Jim Donovan

20+ Footer - Building in Hawaii

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I would think the same.

However the tactical dude that was on the 20 with us said blow the halyard, I did. (he has won a few big events) The boat came up quickly followed by horking the spin right back up, before it totally shrimps. I think it was quicker than jumping on the keel. The boat didnt seem to have any desire to come up otherwise.

 

 

How much wind was there?

 

This is true in the 24 and 32 also, if it's blowing hard enough (20-25+) the boat is still very difficult to get back on its feet even after blowing sheet and vang. If the halyard gets blown halfway the boat will turn down much easier. The kite won't shrimp as long as you are quick to get it back up with the sheet eased. There are a few examples of this on youtube, most noteable Bilksem training video in Sardinia:

 

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I would think the same.

However the tactical dude that was on the 20 with us said blow the halyard, I did. (he has won a few big events) The boat came up quickly followed by horking the spin right back up, before it totally shrimps. I think it was quicker than jumping on the keel. The boat didnt seem to have any desire to come up otherwise.

 

 

How much wind was there?

 

This is true in the 24 and 32 also, if it's blowing hard enough (20-25+) the boat is still very difficult to get back on its feet even after blowing sheet and vang. If the halyard gets blown halfway the boat will turn down much easier. The kite won't shrimp as long as you are quick to get it back up with the sheet eased. There are a few examples of this on youtube, most noteable Bilksem training video in Sardinia:

 

 

That guy dragging in the water on the leeward side is going to be a problem - the spinnaker needed to come down in that episode.

Wipe-outs on the M24s in Kaneohe Bay are the norm and afflict even the best crews.

We never drop the halyards - simply roll-out the jib and hike the best you can on the near vertical deck will always get the boat back upright. It might take a minute, but at least your right back into the race with the spinnaker up.

 

But all of this is slow compared to a boat like my design with higher stability and a deeper rudder.

I can't guarantee the boat will never wipe-out (a bad gybe is typically the cause), but I can assure you that the much heavier bulb on a deeper fin will definitely right the boat much quicker.

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Finishing up cockpit details including footbraces, jib and vang cleat box, and started on the sprit today.

My friend Harold brought by an I14 mast a few months ago asking if I could fix it.

Fixing it "right" so it didn't have any hard spots caused by the repair would cost more than a new mast tube.

So Harold has his new mast and he has donated the broken top part to my boat project.

Today I started fitting it to the bow - I need to cut it down a bit and it will need reinforcing to handle the compression and bending loads.

I'm going to start with a 1.20m (4 ft) long sprit to see how that goes.

This gives me a TPS approx 8" longer than a Melges 24.

I figure I can always cut it down if it seems too long - I suspect we will like the length.

Footbraces (upside down) in the foreground - should glue down the fwd set tomorrow - the shorter aft set are adjustable and removable.

 

 

Would be a shame to cut it Jim!

 

Don't do it! Don't do it!

 

(on the shaw we had a 3m prod which gives a nice amount of lift)

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Finishing up cockpit details including footbraces, jib and vang cleat box, and started on the sprit today.

My friend Harold brought by an I14 mast a few months ago asking if I could fix it.

Fixing it "right" so it didn't have any hard spots caused by the repair would cost more than a new mast tube.

So Harold has his new mast and he has donated the broken top part to my boat project.

Today I started fitting it to the bow - I need to cut it down a bit and it will need reinforcing to handle the compression and bending loads.

I'm going to start with a 1.20m (4 ft) long sprit to see how that goes.

This gives me a TPS approx 8" longer than a Melges 24.

I figure I can always cut it down if it seems too long - I suspect we will like the length.

Footbraces (upside down) in the foreground - should glue down the fwd set tomorrow - the shorter aft set are adjustable and removable.

 

 

Would be a shame to cut it Jim!

 

Don't do it! Don't do it!

 

(on the shaw we had a 3m prod which gives a nice amount of lift)

 

Finishing up cockpit details including footbraces, jib and vang cleat box, and started on the sprit today.

My friend Harold brought by an I14 mast a few months ago asking if I could fix it.

Fixing it "right" so it didn't have any hard spots caused by the repair would cost more than a new mast tube.

So Harold has his new mast and he has donated the broken top part to my boat project.

Today I started fitting it to the bow - I need to cut it down a bit and it will need reinforcing to handle the compression and bending loads.

I'm going to start with a 1.20m (4 ft) long sprit to see how that goes.

This gives me a TPS approx 8" longer than a Melges 24.

I figure I can always cut it down if it seems too long - I suspect we will like the length.

Footbraces (upside down) in the foreground - should glue down the fwd set tomorrow - the shorter aft set are adjustable and removable.

 

 

Would be a shame to cut it Jim!

 

Don't do it! Don't do it!

 

(on the shaw we had a 3m prod which gives a nice amount of lift)

I agree but you really didn't have to say it 4 times.

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The past week has been mostly devoted to adding reinforcements for the rigging and sanding and painting and sanding and painting and . . .

I got a second "final" coat of primer on the deck tonight - I think it's finally ready for the final paint.

 

The bow laminate is complete, and I've added the fairlead for the forestay and a folding padeye for various uses; towing, mooring, etc. . .

 

Splicing the mast together now, and getting ready to build the sprit.

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I’ve got the entire boat primed and sanded to 180, pretty much ready for finish paint. Still working on the chines - this takes a lot of patience and is "complicated" with the boat right side up.

 

Talked to a friend about spraying the topsides and deck – he’s one of the the best yacht painters in Hawaii – got to get the paint right to have the boat look it;s best.

 

Been working on the mast – joined the broken halves, and I’m building the little 20” long piece I need to add to the bottom so I can keel step it.

Want to get the rig ready to paint alongside the boat

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Interesting snapshot I took from Charleston Race Week video today. M20 planted in a knock down with a crew needing to jump on the keel to get the boat back upright.

Looks like it's blowing about 20+, which is an average day here in Hawaii.

 

Wonder what 30 knots will be like?

 

 

Keel bulb on my boat weighs the same as a Melges 24 (approx 580 lbs).

In all my years of sailing M24's in big breeze, I have never even gotten close to jumping out on the fin to get the boat upright.

This heavy bulb on my smaller design will speed up the recovery of the boat in a knockdown - I want to be able to sail in 30 knots without dealing with the prolonged wipe-outs, and never want my crew over the side to get the boat back upright.

 

 

That's funny Jim. I was just watching the same video before checking on how your build is coming....I do have to compliment the guy who jumped on the keel, must be a dinghy sailor...but I sail in SF and like your thoughts on having a bit of lead down there....

 

 

The smaller sporty keel boats paired with dinghy sailors you tend to get a dinghy sailor or two who by instinct head for the keel when its blowing hard and you park it on the side. I've had to yank a few dinghy crew back in the cockpit on the U20 over the years and explain what a keel is for. LOL

 

I was discussing this with my friends who sail Melges 24s here in Hawaii.

All of these guys have sailed high powered dingies - one of them has an Olympic silver medal.

We've all taken M 24’s out in way too much wind and really "scary" conditions where wipe-outs are a certainty.

I asked them if they've ever even considered jumping out on the fin on their 24's - they said "never have, no need too".

 

In that video the M 20 looked fairly well pinned down and staying on it's side. That changed when the guy got out on the fin.

 

I've sailed some keel boats that have a similar low limit of positive stability, and the long recovery period from a wipe-out will take you out of the race.

 

 

I've been racing SF Bay a long time did foredeck for years and years on the J/24's and Express 27's then some bigger boats. The one thing I learned having raced the U20 since 99 along with afew other Asymmetric boats like the Antrim 27 is that the symmetric sailors when we get blown flat will keep the symmetric up and essentially wait for the boat to get back on its feet unless of course its clear that the boat is not comming up then we douse. On the asymmetrics the kites tend to be larger vs the size of the boat so when you get blasted flat with the Asymmetric and its clear the boat is down for the count - you just douse the assymetric while your on your side get going again and reset. It took a shreaded kite and busted instrument wand on of the big boats I sailed on before the owner former symmetric sailor agreed that there is a very clear point at which the Asymmetric rig just needs to be doused and the old Symmetric wait it out is not a good idea.

 

Keep in mind the assymmetric boats these days are light flat platforms with big kites the amount of wind you need to pin your self down is no where near what the older symmetric rigs could take given the kites were way smaller vs the weight of the boat ie keel etc.

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I’ve got the entire boat primed and sanded to 180, pretty much ready for finish paint. Still working on the chines - this takes a lot of patience and is "complicated" with the boat right side up.

 

Talked to a friend about spraying the topsides and deck – he’s one of the the best yacht painters in Hawaii – got to get the paint right to have the boat look it;s best.

 

Been working on the mast – joined the broken halves, and I’m building the little 20” long piece I need to add to the bottom so I can keel step it.

Want to get the rig ready to paint alongside the boat

 

Jim,

Can't wait to see the painted and rigged boat. I think I check for this thread at least five times a week at this point. Fun stuff...

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Interesting snapshot I took from Charleston Race Week video today. M20 planted in a knock down with a crew needing to jump on the keel to get the boat back upright.

Looks like it's blowing about 20+, which is an average day here in Hawaii.

 

Wonder what 30 knots will be like?

 

 

Keel bulb on my boat weighs the same as a Melges 24 (approx 580 lbs).

In all my years of sailing M24's in big breeze, I have never even gotten close to jumping out on the fin to get the boat upright.

This heavy bulb on my smaller design will speed up the recovery of the boat in a knockdown - I want to be able to sail in 30 knots without dealing with the prolonged wipe-outs, and never want my crew over the side to get the boat back upright.

 

 

That's funny Jim. I was just watching the same video before checking on how your build is coming....I do have to compliment the guy who jumped on the keel, must be a dinghy sailor...but I sail in SF and like your thoughts on having a bit of lead down there....

 

 

The smaller sporty keel boats paired with dinghy sailors you tend to get a dinghy sailor or two who by instinct head for the keel when its blowing hard and you park it on the side. I've had to yank a few dinghy crew back in the cockpit on the U20 over the years and explain what a keel is for. LOL

 

I was discussing this with my friends who sail Melges 24s here in Hawaii.

All of these guys have sailed high powered dingies - one of them has an Olympic silver medal.

We've all taken M 24’s out in way too much wind and really "scary" conditions where wipe-outs are a certainty.

I asked them if they've ever even considered jumping out on the fin on their 24's - they said "never have, no need too".

 

In that video the M 20 looked fairly well pinned down and staying on it's side. That changed when the guy got out on the fin.

 

I've sailed some keel boats that have a similar low limit of positive stability, and the long recovery period from a wipe-out will take you out of the race.

 

 

I've been racing SF Bay a long time did foredeck for years and years on the J/24's and Express 27's then some bigger boats. The one thing I learned having raced the U20 since 99 along with afew other Asymmetric boats like the Antrim 27 is that the symmetric sailors when we get blown flat will keep the symmetric up and essentially wait for the boat to get back on its feet unless of course its clear that the boat is not comming up then we douse. On the asymmetrics the kites tend to be larger vs the size of the boat so when you get blasted flat with the Asymmetric and its clear the boat is down for the count - you just douse the assymetric while your on your side get going again and reset. It took a shreaded kite and busted instrument wand on of the big boats I sailed on before the owner former symmetric sailor agreed that there is a very clear point at which the Asymmetric rig just needs to be doused and the old Symmetric wait it out is not a good idea.

 

Keep in mind the assymmetric boats these days are light flat platforms with big kites the amount of wind you need to pin your self down is no where near what the older symmetric rigs could take given the kites were way smaller vs the weight of the boat ie keel etc.

 

The bigger kites on modern boats definitely pin you down longer, but what really matters is the stability of the boat.

The more stable the boat, the quicker the recovery.

In the old days (late 70s/early 80s) we sailed these dagger keel boats that had ridiculously light keel fins with all the ballast in the bilge.

You'd even raise the keel downwind, so there was almost no lead below the bottom of the hull.

After some extremely frightening knockdowns in those awful boats, you get an appreciation for high stability keel solutions!

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I’ve got the entire boat primed and sanded to 180, pretty much ready for finish paint. Still working on the chines - this takes a lot of patience and is "complicated" with the boat right side up.

 

Talked to a friend about spraying the topsides and deck – he’s one of the the best yacht painters in Hawaii – got to get the paint right to have the boat look it;s best.

 

Been working on the mast – joined the broken halves, and I’m building the little 20” long piece I need to add to the bottom so I can keel step it.

Want to get the rig ready to paint alongside the boat

 

Jim,

Can't wait to see the painted and rigged boat. I think I check for this thread at least five times a week at this point. Fun stuff...

 

I have to apologize for the thin posts these past days, but the seemingly endless process of getting the boat ready for the topcoat is not photogenic, unless you like looking at photos of white paint.

 

I'll get a few shots of Brett's rudder and the little mast part I'm building.

Also hope to get the laminate for the sprit base laminated on the stem today.

 

Had a minor success story yesterday - "tweaked" the port chine so it's looking good.

Of course I sanded through the primer in a few spots, so guess what?

I get to re-prime and the chine (it will take at least 2 coats)and It looks like a few more hours of sanding . . .

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On a slightly different subject (I'll start a separate topic for this later):

 

I am working on a design a for a very similar boat to the D6 for the many people who have asked if they can just buy the plans to build the entire boat themselves.

 

The design will be for strip planked construction; either wood or core cell planking.

 

 

The plans for the hull and deck will sell for approx US$650, which will include a full size mylar for the hull mold stations and internal framing.

 

 

We will also start construction of a strip planked hull (to be used for the D6 production plug) built exactly the same as a boat described in the plans.

 

We’ll photograph the plug construction and write up assembly notes and post them on our website.

 

Plan purchasers will be able to sign in and view, ask questions, add comments, and use the website as their construction manual.

 

 

I’m also thinking I will offer 25 and 28 foot versions utilizing the same construction methods.

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On a slightly different subject (I'll start a separate topic for this later):

 

I am working on a design a for a very similar boat to the D6 for the many people who have asked if they can just buy the plans to build the entire boat themselves.

 

The design will be for strip planked construction; either wood or core cell planking.

 

 

The plans for the hull and deck will sell for approx US$650, which will include a full size mylar for the hull mold stations and internal framing.

 

 

We will also start construction of a strip planked hull (to be used for the D6 production plug) built exactly the same as a boat described in the plans.

 

We’ll photograph the plug construction and write up assembly notes and post them on our website.

 

Plan purchasers will be able to sign in and view, ask questions, add comments, and use the website as their construction manual.

 

 

I’m also thinking I will offer 25 and 28 foot versions utilizing the same construction methods.

 

NICE - Bigger versions? Cool. B)

 

I've wanted an updated Olson 30. Basic, fast, stable, offshore capable with no extras (engine, head, galley - make those options).

 

D28 aka 'Stretched D20' with sitting room should fit the bill nicely.

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On a slightly different subject (I'll start a separate topic for this later):

 

I am working on a design a for a very similar boat to the D6 for the many people who have asked if they can just buy the plans to build the entire boat themselves.

 

The design will be for strip planked construction; either wood or core cell planking.

 

 

The plans for the hull and deck will sell for approx US$650, which will include a full size mylar for the hull mold stations and internal framing.

 

 

We will also start construction of a strip planked hull (to be used for the D6 production plug) built exactly the same as a boat described in the plans.

 

We’ll photograph the plug construction and write up assembly notes and post them on our website.

 

Plan purchasers will be able to sign in and view, ask questions, add comments, and use the website as their construction manual.

 

 

I’m also thinking I will offer 25 and 28 foot versions utilizing the same construction methods.

 

NICE - Bigger versions? Cool. B)

 

I've wanted an updated Olson 30. Basic, fast, stable, offshore capable with no extras (engine, head, galley - make those options).

 

D28 aka 'Stretched D20' with sitting room should fit the bill nicely.

 

I think I should start a new topic now ?

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More Photos:

 

Started the bow sprit base

 

The 20" long mast bottom extension part was not cured enough to fit to the mast, so I used the Hawaiian style "oven" to post cure the part - you can get black carbon parts up to 160 degrees, but you have to be careful and rotate the part.

 

The deck primer is complete with footbraces, parrot perch base, and jib sheet/vang thru-deck riser installed on the cockpit sole. Helm footbraces are movable/removable - I want to have some adjustment for various sized drivers, and then take them off completely for "cruising to the sand bar. With the aft footbraces removed, the cockpit aft of the traveler is huge (for a 20 footer); approx 4 ft x 5 1/2 ft - plenty of room to stretch out and relax. A full deck awning is going to be an essential piece of cruising gear.

 

Brett's rudder halves with the primary structural laminates are completed - the blade is VERY long at almost 7 feet long, although the upper 18" sticks into a cassette. The lower 4.5' of the blade is the same as for my 20. I always error on making rudders longer than you might you need - it's always easy to shorten them (never happens).

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Lot's of small projects going simultaneously in the shop:

 

Glued sprit to the base - next step is to add some bonding laminate then some foam wedges to increase the section size at the inboard end. Over the foam will be the structural laminate - the current I-14 topmast tube acts more like a mandrel for the sprit - it'll be quite strong in compression, but it needs to be bigger in cross-section to handle bending loads.

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Added small extension piece to mast - ready to get structural laminate added today.

 

Cleaning up the excess laminate from Brett's rudder blades - ready to get some faring before bonding the halves together.

I added a sketch of the D6 rudder head on Brett's blade to give an idea of the size.

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What are you using for footbraces? I'm interested to see how they would shorten.

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What are you using for footbraces? I'm interested to see how they would shorten.

 

The helm footbraces simply screw into 4 x threaded inserts in the cockpit sole.

I have them positioned fairly far outboard initially, and will add other positions as needed.

You can see them in the photos - they are the short footbraces aft of the traveler,

I'll try and remember to get a photo of them - they are really simple parts.

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More progress on sprit today - added foam on centerline and sides, another layer of twill added to the base molding

I will fill in between with more foam to give the sprit a triangular section as it comes to the stem.

 

Added more laminate to the mast extension at the bottom - one more structural laminate goes on tomorrow.

Thin pass of microlight filler over the +/- 45s I added in the repair area - just wanted a little extra "just in case".

 

"Dialed in" the starboard side chine toady, then painted the chines P&S before leaving the shop (after I took this photo).

I like the look of the boat with it's sprit a lot!

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More progress on sprit today - added foam on centerline and sides, another layer of twill added to the base molding

I will fill in between with more foam to give the sprit a triangular section as it comes to the stem.

 

Added more laminate to the mast extension at the bottom - one more structural laminate goes on tomorrow.

Thin pass of microlight filler over the +/- 45s I added in the repair area - just wanted a little extra "just in case".

 

"Dialed in" the starboard side chine toady, then painted the chines P&S before leaving the shop (after I took this photo).

I like the look of the boat with it's sprit a lot!

 

 

Jim I have been following the costruction of the little fella since it had started and the boat is really impressive but as a Structural-Bridge Engineer I am a bit worried about the loads and the bending moments that your sprit has to withstand and the resulting compressive-tensile loads on the stem. Why didn't you go for a pinned sprit solution (the sprint is fixed at the bow with one or two pins and a bobstay)as they do it on the TP52????

 

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More progress on sprit today - added foam on centerline and sides, another layer of twill added to the base molding

I will fill in between with more foam to give the sprit a triangular section as it comes to the stem.

 

Added more laminate to the mast extension at the bottom - one more structural laminate goes on tomorrow.

Thin pass of microlight filler over the +/- 45s I added in the repair area - just wanted a little extra "just in case".

 

"Dialed in" the starboard side chine toady, then painted the chines P&S before leaving the shop (after I took this photo).

I like the look of the boat with it's sprit a lot!

 

 

Jim I have been following the costruction of the little fella since it had started and the boat is really impressive but as a Structural-Bridge Engineer I am a bit worried about the loads and the bending moments that your sprit has to withstand and the resulting compressive-tensile loads on the stem. Why didn't you go for a pinned sprit solution (the sprint is fixed at the bow with one or two pins and a bobstay)as they do it on the TP52????

 

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You are correct, and I have always planned to have a large pin at the aft extent of the "base" that will take all the compressive and bending loads.

I want to be able to pull this pin easily so I can remove the sprit without too much drama.

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You are correct, and I have always planned to have a large pin at the aft extent of the "base" that will take all the compressive and bending loads.

I want to be able to pull this pin easily so I can remove the sprit without too much drama.

 

Ok I thought it was going to be a permenant fixed sprit....I really like your project I check it every day for new posts and I think everybody that reads your this topic apreciates all the effort in educating us on boatbuilding technics.....

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You are correct, and I have always planned to have a large pin at the aft extent of the "base" that will take all the compressive and bending loads.

I want to be able to pull this pin easily so I can remove the sprit without too much drama.

 

Ok I thought it was going to be a permenant fixed sprit....I really like your project I check it every day for new posts and I think everybody that reads your this topic apreciates all the effort in educating us on boatbuilding technics.....

 

 

I'd need to be able to easily remove it to park the boat in it's parking space, and I'd like to be able to remove it before coming into the dock.

Today, Robert correctly identified the project; his very own carbon fiber perch - he sat there quite content for hours toady - must be a good view from there . . .

 

Thanks for the positive remarks re: my project. I'm very ready to stop building and start sailing.

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You are correct, and I have always planned to have a large pin at the aft extent of the "base" that will take all the compressive and bending loads.

I want to be able to pull this pin easily so I can remove the sprit without too much drama.

 

Ok I thought it was going to be a permenant fixed sprit....I really like your project I check it every day for new posts and I think everybody that reads your this topic apreciates all the effort in educating us on boatbuilding technics.....

 

 

I'd need to be able to easily remove it to park the boat in it's parking space, and I'd like to be able to remove it before coming into the dock.

Today, Robert correctly identified the sprit project; his very own carbon fiber perch - he sat there quite content for hours toady - must be a good view from there . . .

 

Thanks for the positive remarks re: my project. I'm very ready to stop building and start sailing.

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No love with the file opening Jim.

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Big day for the boat - on it's trailer and out of the shop!

Next it'll be heading down the road for a paint job.

Going to be a few weeks before that happens - plenty of other work to tackle right now, including sourcing and installing a trailer hitch for the car.

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Bing! Looks fabtastic Jim!

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Polars are cool...how does ORC factor stability?? I find it tough to believe 9 knots @75 true is achievable without traps?

 

Can I buy polars for other boats from the ORC? Its all relative so comparisons are more important than theory vs actual.

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Polars are cool...how does ORC factor stability?? I find it tough to believe 9 knots @75 true is achievable without traps?

 

Can I buy polars for other boats from the ORC? Its all relative so comparisons are more important than theory vs actual.

 

There is a very good document available on the ORC website that explains their VPP.

You can "buy polars" from the ORC by either gettng a rating from them, or purchasing the designer's version software.

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Can you buy polars for existing club rated boats? I do not know the data fields for the designers software package so if you, as a designer, wanted to do some analysis and comparisons for your boat, a Melges 20 and a Viper 640 how do you go about doing that.....how do you input the Melges and Viper data??

 

Or for the guy who wants a single handed sportboat could you get the polars fro a Melges 24 and a Mini6.5 ( I see that they both have certificates) and design a 23 footer that takes all the best features of both and morph new design criteria to shoot for?

 

Or in designing your GP26 can you get the matrix for existing boats.....not the lines or measurements but just the polar matrix??

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Can you buy polars for existing club rated boats? I do not know the data fields for the designers software package so if you, as a designer, wanted to do some analysis and comparisons for your boat, a Melges 20 and a Viper 640 how do you go about doing that.....how do you input the Melges and Viper data??

 

Or for the guy who wants a single handed sportboat could you get the polars fro a Melges 24 and a Mini6.5 ( I see that they both have certificates) and design a 23 footer that takes all the best features of both and morph new design criteria to shoot for?

 

Or in designing your GP26 can you get the matrix for existing boats.....not the lines or measurements but just the polar matrix??

 

In a very brief message you have asked for a rather large amount of information.

Let me start:

 

You can typically buy certificates for any rated boat - the information is exactly the same as what appears on the certificate, so the amount of information is dependent on the certificate format.

 

If there is a Melges 20 or Viper 640 that have an ORC or ORR certificate (doubtful), then you could purchase those and gain what information you like.

 

To make the VPP runs you need to have accurate hull, keel, rudder, rig and sail dimensions. Without these you have to guess and the output is only as good as your guess.

 

For GP26 you can get any IMS or ORC certs for existing boats, but the information from the certs is not really that informative, especially for a box rule boat like a GP26 where most of the major performance criteria are defined in the rule.

 

I think it's these box rule boats that really make designers explore the shapes that yield the best performance.

You can see quite a subtle but significant evolution in the TP 52 class, with more refined hull shapes appearing in each generation.

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Can you buy polars for existing club rated boats? I do not know the data fields for the designers software package so if you, as a designer, wanted to do some analysis and comparisons for your boat, a Melges 20 and a Viper 640 how do you go about doing that.....how do you input the Melges and Viper data??

 

Or for the guy who wants a single handed sportboat could you get the polars fro a Melges 24 and a Mini6.5 ( I see that they both have certificates) and design a 23 footer that takes all the best features of both and morph new design criteria to shoot for?

 

Or in designing your GP26 can you get the matrix for existing boats.....not the lines or measurements but just the polar matrix??

 

In a very brief message you have asked for a rather large amount of information.

Let me start:

 

You can typically buy certificates for any rated boat - the information is exactly the same as what appears on the certificate, so the amount of information is dependent on the certificate format.

 

If there is a Melges 20 or Viper 640 that have an ORC or ORR certificate (doubtful), then you could purchase those and gain what information you like.

 

To make the VPP runs you need to have accurate hull, keel, rudder, rig and sail dimensions. Without these you have to guess and the output is only as good as your guess.

 

For GP26 you can get any IMS or ORC certs for existing boats, but the information from the certs is not really that informative, especially for a box rule boat like a GP26 where most of the major performance criteria are defined in the rule.

 

I think it's these box rule boats that really make designers explore the shapes that yield the best performance. With the hull parameters, rig size, keel draft, etc. all "locked up", the hull forms become the focus for performance gains.

You can see quite a subtle but significant evolution in the TP 52 class, with more refined hull shapes appearing in each generation.

The VPP data will struggle to accurately predict the actual performance gains from the improved hull forms.

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Thank you, Jim that helps. I really like the box rules because of the reasons you mentioned. I also really like the Mini's but I think they are wrong. I do not know how to test without anyone to sail against. The boats are way too wide and cant be fast to be that fat. The evolution is clear in that the the 10% static heal rule made the boats get wide for increased stability. The 3 basics of speed are DSPL, SA and stability. Since SA is constant then the stiffest boat will perform over the widest range of conditions given nominal weight differences.

I think they have evolved to be too fat and too downwind oriented and the newest boats simply win because they are the lightest best built and have the best sailors.

 

The B/L ratio on the boats is so far off the scale that the boats are crabbing on the keels when heeled. The boats with the shortest cords then induce the least added drag. The worst condition must be tight reaching when healed as the boat wants to sail on the bow to rudder axis but the dagger and the keel are 15% off angle for that???

 

I am just thinking of trying a narrower heavier boat that will out preform the current fatties upwind in all conditions, reaching and in light air.(less wetted)

 

How can I measure the trade for downwind losses in breeze and how steep they would be? The other factor is leg angle % and breeze over the race course.

 

Everything is a trade so If I can trade 10% more speed on 35% of the race course against a 12% loss on 30% and even speed on the other 35% can I win.

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Thank you, Jim that helps. I really like the box rules because of the reasons you mentioned. I also really like the Mini's but I think they are wrong. I do not know how to test without anyone to sail against. The boats are way too wide and cant be fast to be that fat. The evolution is clear in that the the 10% static heal rule made the boats get wide for increased stability. The 3 basics of speed are DSPL, SA and stability. Since SA is constant then the stiffest boat will perform over the widest range of conditions given nominal weight differences.

I think they have evolved to be too fat and too downwind oriented and the newest boats simply win because they are the lightest best built and have the best sailors.

 

The B/L ratio on the boats is so far off the scale that the boats are crabbing on the keels when heeled. The boats with the shortest cords then induce the least added drag. The worst condition must be tight reaching when healed as the boat wants to sail on the bow to rudder axis but the dagger and the keel are 15% off angle for that???

 

I am just thinking of trying a narrower heavier boat that will out preform the current fatties upwind in all conditions, reaching and in light air.(less wetted)

 

How can I measure the trade for downwind losses in breeze and how steep they would be? The other factor is leg angle % and breeze over the race course.

 

Everything is a trade so If I can trade 10% more speed on 35% of the race course against a 12% loss on 30% and even speed on the other 35% can I win.

 

Think this is for a different topic.

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JD,

 

I know Jimmy is spraying a bud's Moore24 at present in the Mapunapuna shop - yours next ?

 

How are the blades coming along ? I'd like to lend a hand ( and see how it's done...)

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JD,

 

I know Jimmy is spraying a bud's Moore24 at present in the Mapunapuna shop - yours next ?

 

How are the blades coming along ? I'd like to lend a hand ( and see how it's done...)

 

Hope so - want to get the mast ready to paint alongside.

 

Blades are probably going to be built in Kauai - big repair project going on over there and I'll have a great shop close by to work on them in the evenings.

Come on over and help!

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what sails are you planning on using?

 

Farrar Sails of course.

Kevin has the spinnaker done, and will start on my main and jib soon.

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This thread needs a bump....

 

Jim where are you at now? Paint shed still?

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This thread needs a bump....

 

Jim where are you at now? Paint shed still?

 

Here's exactly where I am - under the starboard hull now that the port hull repairs are complete and getting fairing now.

This is the 56 catamaran that is getting repaired in Kauai - I'm heading up the composite repairs - should be a few more weeks until we're done with that part of it.

post-3763-127638610267_thumb.jpg

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Last Monday I extracted the boat and trailer (after spending 4 hrs on Saturday dismantling, cutting and drilling, & reassembling the back half of the family "truck" to get the hitch installed.

The hitch manufacturer's 2 hr install estimate assumes you had done the job before and had found all the mistakes in their instructions.

The end result was worth the effort.

 

Photo is from last Monday - spent 4 days working on the big cat on Kauai and today I am still collecting misc parts and equipment from Brett's garage.

Hope to get the boat to the paint shed next week.

post-3763-127638570202_thumb.jpg

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No love with the file opening Jim.

Try again - let me know if this is any better.

 

For some reason the text dropped out on the TWS wind bands on the previous post.

They are 6, 8,10,12,14,16 & 20

 

It raises some questions on the resolution and interpolation of the ORC speed guide polars (look at the 16knot lines) at @130deg true the graphical red assym line bulges out due to trying to fit the curve to the points so that it is infact in excess of the downwind best vmg in the table.

 

Which do you believe ?

 

I would like to see more polars at higher wind strengths considering the winter average of 18knots local to me, but I think thats asking a bit much from the VPP.

 

Though it would be nice to validate the actual speeds for that polar?

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Update please.

 

Too much work on other people's boat projects right now taking me away from my boat.

Boom and rudder construction are underway, so keel fin is the next step to start concentrating on

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You should have a bunch of folks that read this site coming your way in two weeks or so- would you be able/interested in setting up a "viewing" of the boat for the folks that want to see it?

Absolutely - the boat is about 1 mile by water, and 4 miles down the road from Kaneohe Yacht Club.

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You should have a bunch of folks that read this site coming your way in two weeks or so- would you be able/interested in setting up a "viewing" of the boat for the folks that want to see it?

Absolutely - the boat is about 1 mile by water, and 4 miles down the road from Kaneohe Yacht Club.

Swell- I'll look here or give a shout when we're there and see what works.

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You should have a bunch of folks that read this site coming your way in two weeks or so- would you be able/interested in setting up a "viewing" of the boat for the folks that want to see it?

Absolutely - the boat is about 1 mile by water, and 4 miles down the road from Kaneohe Yacht Club.

Swell- I'll look here or give a shout when we're there and see what works.

 

So Joe and I wrapped up the composite repairs on the big cat in Kauai and I have a week or so off at home.

I need to reinstall my hitch fitting on the 20 (had to shortened the trailer tongue to fit in my parking space)to go mobile.

Possible to drag it by KYC if I can get the kind folks over there to open the gate.

Let me know when you'll be around and I'll try and arrange a "showing".

Note that the boat is stripped of hardware and still wearing primer, so not a finished yacht yet.

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Much thanks for the chance to see the work up close, Jim.

 

And to others- Jim has a clear idea of what this boat is about, and has hit his targets quite precisely- you could tell how as he explained how each curve was meant to create which effect on each portion of the overall envelope. Being one's own client can be rewarding that way- no concessions to the wayward client's whims. A boat with a clear design vision seems always to come out better than one with too many "features" requested- 10 pounds of sand in a 5 pound box sort of issues. None of that here...

 

Jim's work is uber clean and tidy, makes me feel like like a carbon butcher. Oh well, something to shoot for isn't it?

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Much thanks for the chance to see the work up close, Jim.

 

And to others- Jim has a clear idea of what this boat is about, and has hit his targets quite precisely- you could tell how as he explained how each curve was meant to create which effect on each portion of the overall envelope. Being one's own client can be rewarding that way- no concessions to the wayward client's whims. A boat with a clear design vision seems always to come out better than one with too many "features" requested- 10 pounds of sand in a 5 pound box sort of issues. None of that here...

 

Jim's work is uber clean and tidy, makes me feel like like a carbon butcher. Oh well, something to shoot for isn't it?

So a guy with a six-pack of beers walks into a parking garage to see a boat, and what happens?

He ends up risking digit amputation while helping the "yacht designer" mangle his trailer.

So the moral of the story - make sure the boat you're going to look at is finished, or wear something that can handle a few grease/epoxy stains.

 

 

Trailer modification turned out good - remind me to tighten those nylocks we couldn't get to before I drive off with the boat.

Thanks for all your help - I'll try and catch up with you at KYC tonight.

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Any more ideas on the kit or plans for home builder ?

 

Have a look at the "homebuilt plans" discussion in the "homebuilt 30 footer" topic.

Same sort of concept for the 20 footer home builder plans - similar boat but design tailored to homebuilt material spec.

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Thanks Jim, though when you started out on th 20 you were thinking of kit boat where some components would possibly be pre manufactured, are you heading more to a set of plans only.

 

Plywood construction ?

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Thanks Jim, though when you started out on th 20 you were thinking of kit boat where some components would possibly be pre manufactured, are you heading more to a set of plans only.

 

Plywood construction ?

Plans still on to build, but economy still looking grim, so we sit and wait until we know there will be eniough buyers to make it all worth while.

 

Have a few interested plans buyers, but need a few more to get the price of the paln set reasonably low. Also need to try and get everyone to line up for a single construction method - the foam and glass boat is not the same as a plywood boat.

 

Maybe it's time for anyone truely interested in a plan set to chime in and let me know their material preferences.

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I am happy to be guided by your recomendation re construction methods,

 

foam and glass probably a bit lighter ?, cost not significantly different ?

 

Who's interested ?

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I am happy to be guided by your recomendation re construction methods,

 

foam and glass probably a bit lighter ?, cost not significantly different ?

 

Who's interested ?

So far today we have 1 plywood and 1 foam and glass.

 

Note that there is no way to build the hull bottom in plywood - so that bit is going to need to be foam and glass.

Since you're already building the hull bottom in foam and glass, it seems natural to build the rest of it from the same materials.

 

But if you have to have wood in our boat, then the topsides and deck panels could be plywood, but don't expect that to be a "cheap" way to build the boat.

The cost savings using plywood for these parts is so small that it is not worth the weight gain.

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I am not sure if I can bring this about, but there is a cheap way to built a hull. A cheap and an easy way. Cold molded plywood.

No critical laminates.

No vacuum needed.

Easy to fair.

Could be done alone.

 

I built mine this way.

 

I used cheap 3mm (1/8) lauwan or meranti door panels, covered inside outside with 200gr (6 ounces) glass epoxy. Weigth about 30 grs/sqf (1.1 lbs) for 3 layers: 10mm (3/8 inches)

It makes a strong and stiff hull resistant to dents and print through.

 

Add to that Mr. Donovan terrific foam and carbon structure designs and you have the best of both world.

 

Voilà

 

Christian.

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I am not sure if I can bring this about, but there is a cheap way to built a hull. A cheap and an easy way. Cold molded plywood.

No critical laminates.

No vacuum needed.

Easy to fair.

Could be done alone.

 

I built mine this way.

 

I used cheap 3mm (1/8) lauwan or meranti door panels, covered inside outside with 200gr (6 ounces) glass epoxy. Weigth about 30 grs/sqf (1.1 lbs) for 3 layers: 10mm (3/8 inches)

It makes a strong and stiff hull resistant to dents and print through.

 

Add to that Mr. Donovan terrific foam and carbon structure designs and you have the best of both world.

 

Voilà

 

Christian.

 

Hi Christian,

 

Your proposed method was quite a common way to build one-off race boats prior to wide acceptance of foam cores for hull construction.

Remember that your 3/8" thick hull panel is not particularly stiff, so you will need to have a lot of framing inside the hull.

Lots of framing equals lots of labor hours.

 

There is a concern in using "cheap . . . lauwan or meranti" in that with lauan you really don't know what species wood you have, and more often than not, the material is very low grade.

 

From Wikipedia: " lauan, is the common name for a wood yielded by some species of the genus Shorea, or perhaps more accurately the name for a group of woods. These are medium density woods, with rather favorable properties, but they are not a mahogany, nor are they comparable in quality. It is not necessarily imported from the Philippines, nor is it limited to species which occur in the Philippines."

 

Okume is a better choice.

 

Also with the typical door panel there is some unknown core material that can be complete crap - better to go with veneers. If you use plywood, make sure it is like "aircraft grade", which uses solid veneers of the same wood species throughout. Brunyzeel is beautiful plywood - not cheap - but I've cut 25 year old pieces of it out of boats that looked brand new.

 

 

For me, I'd look at strip planking the hull bottom with Western Red Cedar. If good quality Port Orford or Alaskan Yellow Cedars are available, they're even better woods.

Strip planking needs a very simple framework, and the grain of the wood is oriented to give the hull better longitudinal stiffness.

 

For all the time and effort you are going to put into building the hull, it makes zero sense to use the cheapest materials. You'll substancially reduce the lifetime of the part, and it's value will probably be reduced by more than the savings in material cost.

 

Below is the strip planked GP26 plug in Turkey - same concept for building a 20 hull, but you could use plywood for the topsides panels.

post-3763-074909500 1284233201_thumb.jpg

post-3763-072201200 1284233228_thumb.jpg

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Jim - Your comments are spot on! One of the reasons I watch this thread is to learn as I dream about taking on such a project.

 

Why on earth would you build something like this using old technology? Wood is great, but get with the times and use foam / fiberglass. The "cost" is not in the material rather it is in the "man hours". Foam core, fiberglass will save time and yield a much better finished product.

 

Keep on, keeping on!

 

 

 

 

I am not sure if I can bring this about, but there is a cheap way to built a hull. A cheap and an easy way. Cold molded plywood.

No critical laminates.

No vacuum needed.

Easy to fair.

Could be done alone.

 

I built mine this way.

 

I used cheap 3mm (1/8) lauwan or meranti door panels, covered inside outside with 200gr (6 ounces) glass epoxy. Weigth about 30 grs/sqf (1.1 lbs) for 3 layers: 10mm (3/8 inches)

It makes a strong and stiff hull resistant to dents and print through.

 

Add to that Mr. Donovan terrific foam and carbon structure designs and you have the best of both world.

 

Voilà

 

Christian.

 

Hi Christian,

 

Your proposed method was quite a common way to build one-off race boats prior to wide acceptance of foam cores for hull construction.

Remember that your 3/8" thick hull panel is not particularly stiff, so you will need to have a lot of framing inside the hull.

Lots of framing equals lots of labor hours.

 

There is a concern in using "cheap . . . lauwan or meranti" in that with lauan you really don't know what species wood you have, and more often than not, the material is very low grade.

 

From Wikipedia: " lauan, is the common name for a wood yielded by some species of the genus Shorea, or perhaps more accurately the name for a group of woods. These are medium density woods, with rather favorable properties, but they are not a mahogany, nor are they comparable in quality. It is not necessarily imported from the Philippines, nor is it limited to species which occur in the Philippines."

 

Okume is a better choice.

 

Also with the typical door panel there is some unknown core material that can be complete crap - better to go with veneers. If you use plywood, make sure it is like "aircraft grade", which uses solid veneers of the same wood species throughout. Brunyzeel is beautiful plywood - not cheap - but I've cut 25 year old pieces of it out of boats that looked brand new.

 

 

For me, I'd look at strip planking the hull bottom with Western Red Cedar. If good quality Port Orford or Alaskan Yellow Cedars are available, they're even better woods.

Strip planking needs a very simple framework, and the grain of the wood is oriented to give the hull better longitudinal stiffness.

 

For all the time and effort you are going to put into building the hull, it makes zero sense to use the cheapest materials. You'll substancially reduce the lifetime of the part, and it's value will probably be reduced by more than the savings in material cost.

 

Below is the strip planked GP26 plug in Turkey - same concept for building a 20 hull, but you could use plywood for the topsides panels.

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Oups, I guess me and everyone should forget about lauan.

Thanks Mr.Donovan for all your inputs. It is very eye opening.

I agree with you that using fancy plywood or high quality cedar do not make a cheaper built than foam. I understand your preferences.

And of course, the builder using the grp method needs a good building plan for proper foam density and laminating schedule. And you have demonstrated that you know your stuff. I was quite fascinated following your built in this thread.

I hope that enough readers will make the jump and buy plans. I would like very much to see the D20 take the same momentum than say the i550.

 

Voilà

 

Christian.

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Oups, I guess me and everyone should forget about lauan.

Thanks Mr.Donovan for all your inputs. It is very eye opening.

I agree with you that using fancy plywood or high quality cedar do not make a cheaper built than foam. I understand your preferences.

And of course, the builder using the grp method needs a good building plan for proper foam density and laminating schedule. And you have demonstrated that you know your stuff. I was quite fascinated following your built in this thread.

I hope that enough readers will make the jump and buy plans. I would like very much to see the D20 take the same momentum than say the i550.

 

Voilà

 

Christian.

I highly reccommend for anyone who's contemplating building a wooden boat to get a copy of "The Gougeon Bros. on Wooden Boat Construction". My copy disappeared many years ago - time to get a new copy I think.

post-3763-090387900 1284311850_thumb.jpg

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Guys in my opinion I think that glass/foam is the optimum solution for the amateur builder and for the richer ones the carbon/foam construction. Why not take andantage of the todays tech and the experience of Jim.....(I am following this thread from the start and I think that Jim demostrated to all of us most of the boat costruction in detail and all the possible points that must have the extra care) I am sure that his drawings and the construction guidelines will create no problem at all for the ammateur builder....

 

 

Jim can you give us an update on the status of your boat, have you managed to progress with it at all?

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I think for an inexperienced home builder strip planking is still a good and easy way to built a boat:

1. it is much easier to get the hull form right, because the wood acts as a spline.

2. wood is easy to work with

3. a lot of people have the right tools at home

4. you can see instant progress

5. when you have a look at the shaw 650s the boats seem to be marginally heavier.

 

using foam strips might be an alternative...

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Guys in my opinion I think that glass/foam is the optimum solution for the amateur builder and for the richer ones the carbon/foam construction. Why not take andantage of the todays tech and the experience of Jim.....(I am following this thread from the start and I think that Jim demostrated to all of us most of the boat costruction in detail and all the possible points that must have the extra care) I am sure that his drawings and the construction guidelines will create no problem at all for the ammateur builder....

 

 

Jim can you give us an update on the status of your boat, have you managed to progress with it at all?

I've become extremely busy with other projects the past few months, so the boat just sits patiently waiting . . .

post-3763-040567200 1284402420_thumb.jpg

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Oups, I guess me and everyone should forget about lauan.

Thanks Mr.Donovan for all your inputs. It is very eye opening.

I agree with you that using fancy plywood or high quality cedar do not make a cheaper built than foam. I understand your preferences.

And of course, the builder using the grp method needs a good building plan for proper foam density and laminating schedule. And you have demonstrated that you know your stuff. I was quite fascinated following your built in this thread.

I hope that enough readers will make the jump and buy plans. I would like very much to see the D20 take the same momentum than say the i550.

 

Voilà

 

Christian.

I highly reccommend for anyone who's contemplating building a wooden boat to get a copy of "The Gougeon Bros. on Wooden Boat Construction". My copy disappeared many years ago - time to get a new copy I think.

 

My fourth copy is in a locked lexan case.

The material used in hull construction is partially determined by the shape of a particular design. Round bilge boats, even those with a vestigial chine, lend themselves to strip planking in either wood or foam strips or heat formed panels. Also the progress reports from Kevin Farrar's build of Jim's GP 26 are really neat to follow. If the budget allows use the lightest material to do the job. The Sharpie hull shape (e.g. i550) is a good example of ply as a reasonable building material. Shape , size, Class weight, method of construction, cost of materials and sailing performance all overlap at a sweet spot which is approachable for an amateur, hence its growth in numbers.

I am a great fan of Jim Donovan's work. Maybe a lanyard on your next copy of Gougeons will keep it near.

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Had to dig back to Page 5 to find this thread!

 

It has been a while since I've had any free moments to even think about the 20.

Been working on a BIG boat project; 26m design for a very fast racer/crusier - carbon prepreg, 18ft deep lifting keel, twin rudders, wine cooler, icemaker, washer/dryer, dishwasher, AC in all the cabins.

 

 

I have break right now, so back to the 20 footer:

 

Boom design is progressing and construction should start in a week or so.

 

 

Sprit is getting carbon laminate over the foam and carbon tube (Harold's old busted I-14 topmast).

Want to drill the hole for the pin before painting he topsdies.

 

And hopefully next week I'll drive the boat over to my friend's shop in Mapunapuna for painting!

post-3763-007555000 1290786384_thumb.jpg

post-3763-027357500 1290786397_thumb.jpg

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What could possibly go wrong ? ? ?

(Robert didn't have to ride lookout at the sharp end the whole trip)

 

Building the mast cradles and trailer tie-down bar (Melges 24 style) today, so grabbed the mast from the side of Brett's house.

post-3763-055724500 1291080591_thumb.jpg

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This looks like a very promising project done by a very knowledgeable designer.

 

Some of you mentioned the possibilities of providing this boat in the form of a kit. I cannot even dream of having the time to built such boat (in fact, what I dream of is just to sail her) but I always wondered if a guy doing ordinary sunday's carpentry and woodwork could have any success with such a project, just following the instructions. How much twist of hand and art (and time) would one need to get this done reasonably right ?

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I might be wrong but i think if the track was oriented more normal to the axis of travel it might be a good thing. It seems like there would be a lot of torque on the the harken track and i have had issues sometimes with those when they are loaded up normal...

 

I'm using a jib sheet arrangement popular on big boats, that gets the load almost vertical to the track.

The jib sheet enters mast 18 feet above deck, and gets double ended in mast, exits the mast below and is lead aft to cleats in cockpit.

The jib sheet will be 3mm dyneema outside the rig to minimize friction and windage.

 

This gets the jib sheet easily in reach of both the crew and helmsman.

I can have either 2 or 4:1 on the sheet (4:1 shown on image).

 

Hello Jim

 

I am new on this forum and only just found this thread but I was so fascinated by it that I read virtualy the whole thing last night so forgive the question about such an old post.

I see on the CAD drawing you have a tackle for the bob stay inside the boat how do you plan to seal it? Also do the halyards run through the bulkhead into the cokpit? If so same question.

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I might be wrong but i think if the track was oriented more normal to the axis of travel it might be a good thing. It seems like there would be a lot of torque on the the harken track and i have had issues sometimes with those when they are loaded up normal...

 

I'm using a jib sheet arrangement popular on big boats, that gets the load almost vertical to the track.

The jib sheet enters mast 18 feet above deck, and gets double ended in mast, exits the mast below and is lead aft to cleats in cockpit.

The jib sheet will be 3mm dyneema outside the rig to minimize friction and windage.

 

This gets the jib sheet easily in reach of both the crew and helmsman.

I can have either 2 or 4:1 on the sheet (4:1 shown on image).

 

Hello Jim

 

I am new on this forum and only just found this thread but I was so fascinated by it that I read virtualy the whole thing last night so forgive the question about such an old post.

I see on the CAD drawing you have a tackle for the bob stay inside the boat how do you plan to seal it? Also do the halyards run through the bulkhead into the cokpit? If so same question.

 

I may stand correction, but I think that is an adjustable forestay led below decks.

 

I'm also curioius how the lines are run. The aft half of the picture!

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I might be wrong but i think if the track was oriented more normal to the axis of travel it might be a good thing. It seems like there would be a lot of torque on the the harken track and i have had issues sometimes with those when they are loaded up normal...

 

I'm using a jib sheet arrangement popular on big boats, that gets the load almost vertical to the track.

The jib sheet enters mast 18 feet above deck, and gets double ended in mast, exits the mast below and is lead aft to cleats in cockpit.

The jib sheet will be 3mm dyneema outside the rig to minimize friction and windage.

 

This gets the jib sheet easily in reach of both the crew and helmsman.

I can have either 2 or 4:1 on the sheet (4:1 shown on image).

 

Hello Jim

 

I am new on this forum and only just found this thread but I was so fascinated by it that I read virtualy the whole thing last night so forgive the question about such an old post.

I see on the CAD drawing you have a tackle for the bob stay inside the boat how do you plan to seal it? Also do the halyards run through the bulkhead into the cokpit? If so same question.

 

 

The tackle in the bow is for the forestay as Herb points out.

 

The bobstay current plan is to anchor it just forward of the forestay fitting inside the boat against the "bulkhead" that is really the aft face of he foam stem piece.

The stay gets pinned inside the boat and runs through a very small tube that I'll seal with some sealant when I pass the stay through it.

I'm goiing to just string the bobstay to the end of the sprit like a bow - it'll probably end up bent down a little unloaded.

This way I'll avoid excess compression from a tensioner running aft from the sprit end.

 

Other holes for strings use the really-small-hole concept of "sealing". Careful alignment of holes just big enough for the line passing through it keeps 99% of the water out of the boat.

It's about as simple a system as posssible. And in a 20 foot sportboat you are going to have to accept that some water will be inside the boat in higher wind speeds.

 

Here's a picture of the hole for the forestay adjuster right by the hatch.

 

There will be a couple waterproofing boxes for the thru-deck blocks going through the cockpit sole and side. You can kind-of see the cockpit sole "box" going in between the fwd footbraces.

There's a cover that fits over the stand-up in the cockpit - the cover has 4 beer holders in it centrally located :).

post-3763-024637600 1291499511_thumb.jpg

post-3763-089546100 1291499761_thumb.jpg

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So Jim, how has the keel come along ? No laminating agqain until things dry out, I know - but if you need somebody to mix while you are aligning fiber tows, I can run the pumps.

 

And seriously, how about a rudder like that ?

 

 

The keel is next on my list, although getting the boat into a shop to get it painted is a priority right now.

Was supposed to drive over to PDF's Mapunapuna shop today, but the 8 inches of rain that fell yesterday morning has created a rather damp enviornment that is not ideal for paint work.

So hopefully the week between X-mas and New Years?

 

Right now I've got Victor's old stand-up paddle board on my shop deck - the one that peeled his roof rack off and flew across all 4 lanes of H-2 before a rather hard landing.

There's some major cracks across the deck and some internal frame damage (it's a hollow carbon board), but I have a scheme for fixing it and plenty of nice 150 gsm carbon

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So Jim, how has the keel come along ? No laminating agqain until things dry out, I know - but if you need somebody to mix while you are aligning fiber tows, I can run the pumps.

 

And seriously, how about a rudder like that ?

 

Getting the balance correct on a cassette rudder is a bit tricky - I've angled the blade forward in the cassette and reduced the distance from the pin axis to the leading edge to as small a distance as possible. More "normal" outboard rudders are easier to balance correctly and end up lighter. The cassette is also an extra piece to build, so more expensive. I'm having a normal outboard rudder for my boat.

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Guess I'm just pre-disposed to the cassette-style as that's whats on my Sonoma. Never thought abut the additional 'off-set' aft though - just how easy it is to pull it.

 

EVERY Thing is a trade off, isn't it ?

 

Still have the Impulse to loan if you need to get out for a small-boat spin with your birds.

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Guess I'm just pre-disposed to the cassette-style as that's whats on my Sonoma. Never thought abut the additional 'off-set' aft though - just how easy it is to pull it.

 

EVERY Thing is a trade off, isn't it ?

 

Still have the Impulse to loan if you need to get out for a small-boat spin with your birds.

 

Are they still racing at Keehi now or stopped until Spring?

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