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Melges 24 Repair


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Hi,

have bought a Melges 24 boat 366. Have some issues and questions.

Issues:

1. Split trailing edge of keel.

2. Damage trailing edge of rudder

3. Hull damages

4. Mast scratches

 

Questions:

A. What paint is used on rudder and keel blade?

B. Any description on repairing the trailing edges, saw posts where clamping has been done.

B.1 Have anyone tried just epoxy glueing the halfs together, is it enough?

B.2 What is inside rudder and keel, does it absorb water and do we need to drain it? The boat has been dry-sailed.

B.3 Do one grinde away carbon material before applying new layers or do you allow it to get a little thicker?

C. Could one use polyester for the hull repairs or should/must vinylester be used?

D. Which gelcoat code does the Melges 24 have och hull and cockpit?

E. What paint type is it on the mast?

F. What type of distnce material is it in the hull sadwich, does it absorb water?

G. Why does the hull get osmosis if it is made of Vinylester, shouldn't it handle water better than polyester?

 

 

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I'll take a stab at a few of them...I have a sibling, #330, have some of this work to do and have done some recently.

A. After repairing my rudder I used Underwater Epoxy on the whole blade.  I need to paint it again but it came out well so far

B. Skipping this one as I have to do the same

C.  Use epoxy for everything.  I think all lamination on the boat is epoxy (see G below, I may be wrong)

D. I used white for repairs and it's a good match.  Just standard white gelcoat.

E. Likely something like Awlgrip which is what I would use to repaint the mast if I was going to do that.  Luckily for me my mast is in pretty good shape.

F. Melges are known for absorbing water which is why so many teams have a dehumidifier for night time use at events with a lot of waves and the cabin gets wet

G. Is the boat Vinylester?  Still think any repairs are better in epoxy or vinyl, don't use polyester.  New vinyls are so good, why use a poly.

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Best advice is to call the guys in Zenda and seek advice.

Interlux performance epoxy for the foils.  

Standard white gelcoat

Keep the foils thin. R/P did a great job on the design.  Rebuilding the trailing edge is tricky. With out pics it is hard to tell how far you have to go. 

Most of our small hull repairs have been done with epoxy.

White awlgrip for older masts, newer ones use clear coats. I've seen older ones painted silver, or black too.

 

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The trailing edge has just split 10-20 cm in two places, doesn't see cracks in the paint of the keel halves carbon material. Question is if gluing them back together is enough or if reinforcement needed before the rest of the trailing edge cracks too.

If reinforcing, how many layers are enough and do one bend it round the edge? Do one grind down some carbon to get space for the reinforcement or is it enough to use the space created by grinding away the paint.

Can one paint Performance epoxy on-top of existing performance epoxy?

Also found osmosis, have anyone handle it on Melges 24, is i just pinholes with water or the whole Vinylester that has dissolved.

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On 9/26/2021 at 4:52 PM, Karukera said:

Hi,

have bought a Melges 24 boat 366. Have some issues and questions.

Issues:

1. Split trailing edge of keel.

2. Damage trailing edge of rudder

3. Hull damages

4. Mast scratches

 

Questions:

A. What paint is used on rudder and keel blade?

B. Any description on repairing the trailing edges, saw posts where clamping has been done.

B.1 Have anyone tried just epoxy glueing the halfs together, is it enough?

B.2 What is inside rudder and keel, does it absorb water and do we need to drain it? The boat has been dry-sailed.

B.3 Do one grinde away carbon material before applying new layers or do you allow it to get a little thicker?

C. Could one use polyester for the hull repairs or should/must vinylester be used?

D. Which gelcoat code does the Melges 24 have och hull and cockpit?

E. What paint type is it on the mast?

F. What type of distnce material is it in the hull sadwich, does it absorb water?

G. Why does the hull get osmosis if it is made of Vinylester, shouldn't it handle water better than polyester?

 

 

Hi Karukera,

 As asked above, any photos of the issues?

 I use a multitool with most thin blade available. This is a very surgical effort. Drive the blade into the trailing edge using little to no force pushing until you hit the void.. You want that blade to cut a clean gap. It's easy to push the teeth past the damage into the void. This pries the halves apart. You want to "hog" (evacuate) material out. I'm not sure if that term translates.  

 The goal is to create a gap between halves without while leaving outside skins in faired plane. Pressure on the inside can cause that crack to open up worse. 

 I laminate a single skin of 3k carbon on a plate surface over mold release. This sheet is gap filler. Once a gap is created I cut the sheet (with scissors) to fit the gap and slide it between halves. You can use any thickened epoxy, I like to use black toughened ProSet. 

 This is where you saw the clamping. I've used old vertical keel guides, wood and aluminum to clamp edges together. For small repairs 2 putty spreaders work beautifully clamped with squeeze clamps. Use thin strip to avoid bridging the trailing edge hollow. Clamp close to the trailing edge to control thickness.

 I'll try to find photos in an old hard drive.

 You cannot perform this repair from the outside without difficult fairing to replace the hollow. I suppose you could perform the repair from one side of the blade but only if you do not feel comfortable with the multitool.

 When the crack has cured you can perfect the outside and trim the skinny repair with ease. Save the sheet of carbon, you will use it again and again.......

 Core is contour foam. Water does get in that core and travels anywhere it can in the open Kerfs.

 Blisters occur at trailer bunks, mostly just gelcoat. 

 Agree vinylester is resin of choice but nearly impossible to source with proper shelf life these days. Go epoxy. However If all you have access to is polyester, you have no choice.

 FYI, IF you need to gel coat over epoxy just wash epoxy with water to remove blush. No soap with water, water alone then sand and coat gel coat. Color will have faded over the years, no good answer on matching.

 

 

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3 hours ago, PeterRoss said:

Hi Karukera,

 As asked above, any photos of the issues?

 I use a multitool with most thin blade available. This is a very surgical effort. Drive the blade into the trailing edge using little to no force pushing until you hit the void.. You want that blade to cut a clean gap. It's easy to push the teeth past the damage into the void. This pries the halves apart. You want to "hog" (evacuate) material out. I'm not sure if that term translates.  

 The goal is to create a gap between halves without while leaving outside skins in faired plane. Pressure on the inside can cause that crack to open up worse. 

 I laminate a single skin of 3k carbon on a plate surface over mold release. This sheet is gap filler. Once a gap is created I cut the sheet (with scissors) to fit the gap and slide it between halves. You can use any thickened epoxy, I like to use black toughened ProSet. 

 This is where you saw the clamping. I've used old vertical keel guides, wood and aluminum to clamp edges together. For small repairs 2 putty spreaders work beautifully clamped with squeeze clamps. Use thin strip to avoid bridging the trailing edge hollow. Clamp close to the trailing edge to control thickness.

 I'll try to find photos in an old hard drive.

 You cannot perform this repair from the outside without difficult fairing to replace the hollow. I suppose you could perform the repair from one side of the blade but only if you do not feel comfortable with the multitool.

 When the crack has cured you can perfect the outside and trim the skinny repair with ease. Save the sheet of carbon, you will use it again and again.......

 Core is contour foam. Water does get in that core and travels anywhere it can in the open Kerfs.

 Blisters occur at trailer bunks, mostly just gelcoat. 

 Agree vinylester is resin of choice but nearly impossible to source with proper shelf life these days. Go epoxy. However If all you have access to is polyester, you have no choice.

 FYI, IF you need to gel coat over epoxy just wash epoxy with water to remove blush. No soap with water, water alone then sand and coat gel coat. Color will have faded over the years, no good answer on matching.

 

 

@PeterRoss as usual you have such good advice.  I'll be saving this for my M24 keel repairs soon.

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Big thank you @PeterRoss!
Will send you pictures. It has split 10-20 cm and at most one can hear by taping that it is 3 cm deep, mostly 1 cm. Only one place with one crack in the paint, so I guess its mostly a split.
Is a Carbon plate needed, isn't the gap tight enough to just use silica thickened epoxy to fill it?
My idea was also to use fiberglass for repair, has the same strength but is more elastic and a little heavier. So shouldn't make a difference. 
Is it a hurry to fix the keel if it splits again, does it accumulate water?
Is the contour foam absorbing water?

Also has scratches due to delrins.
Do you normally fill these with Epoxy filler or paint?
If repainting the keel, does the paint stick to the flour contained in the VC performance epoxy?
Are there alternatives used instead of VC performance epoxy when repainting?
Does the VC performance epoxy handle to be in water a whole season?
Do one need to sand down the old paint to not get a thicker keel?

The bottom delrin fits tight. 
But does the delrins get harder by age and its a good idea to change them to get less scratching?, also guess the collect dirt over the years?
Is it simpler to get a copy made then fitting the ones from Melges?, read that they doesn't fit directly.

Sorry for all questions, but very glad to get answers!

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1 hour ago, Karukera said:

Big thank you @PeterRoss!
Will send you pictures. It has split 10-20 cm and at most one can hear by taping that it is 3 cm deep, mostly 1 cm. Only one place with one crack in the paint, so I guess its mostly a split.
Is a Carbon plate needed, isn't the gap tight enough to just use silica thickened epoxy to fill it?
My idea was also to use fiberglass for repair, has the same strength but is more elastic and a little heavier. So shouldn't make a difference. 
Is it a hurry to fix the keel if it splits again, does it accumulate water?
Is the contour foam absorbing water?

Also has scratches due to delrins.
Do you normally fill these with Epoxy filler or paint?
If repainting the keel, does the paint stick to the flour contained in the VC performance epoxy?
Are there alternatives used instead of VC performance epoxy when repainting?
Does the VC performance epoxy handle to be in water a whole season?
Do one need to sand down the old paint to not get a thicker keel?

The bottom delrin fits tight. 
But does the delrins get harder by age and its a good idea to change them to get less scratching?, also guess the collect dirt over the years?
Is it simpler to get a copy made then fitting the ones from Melges?, read that they doesn't fit directly.

Sorry for all questions, but very glad to get answers!

Performance Epoxy is not an anti-fouling bottom paint.  Depending upon where you are, it might not be good enough.  I'm likely to paint a J22 with it in the Spring and leave the boat in but I fully expect that it will yellow and I'll have to swim on it to keep it clean.  The bonus is that it will keep the hull from absorbing water but again, you're likely better off with a racing bottom paint.

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32 minutes ago, WCB said:

Performance Epoxy is not an anti-fouling bottom paint.  Depending upon where you are, it might not be good enough.  I'm likely to paint a J22 with it in the Spring and leave the boat in but I fully expect that it will yellow and I'll have to swim on it to keep it clean.  The bonus is that it will keep the hull from absorbing water but again, you're likely better off with a racing bottom paint.

I am inshore and know it will grow on it, but I can clean it.

Just interested if the Performance epoxy layer starts blistering, like Polyuretane paint that is not made to be in water.

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@WCB, too kind

@Karukera,

 Water does get in keel, freezing, expanding and splitting keel big danger. Getting the water out completely may never happen. It's in the bulb, in the strut and you are going to have to live with it. You just need to control the level somewhat. 

 I highly recommend investing in a resin trap https://www.ebay.com/itm/224556750819?hash=item3448a017e3:g:xXAAAOSweUhhCB9M 

and vacuum pump

 https://www.ebay.com/itm/132268632855?hash=item1ecbd32b17:g:AEMAAOSwEm1gFBi9

Do not buy the pump/ chamber kit. Those are for degassing and will not pull water. I picked up an addition 100ft of tubing.

 This will be your water evacuation tool used often. You can use it to pull an amazing amount of water out of the hull core from interior and even pull water out of the keel through the top plate holes. You won't pull all water but enough to minimize expansion damage. I'm still looking for missing photo albums, photos showing chamber pulling water.

 Re boat kept in water. Interprotect 2000 barrier coat and Micron Trilux 33 white bottom paint entire hull, keel and rudder if left in. Create a waterline using a laser level.

 

 Delrins. Tough call but best to bite the bullet and buy Melges. Of countless delrins changed only one fit with no effort except cutting to length. It's one of those things you just put up with. 

 

 Keel scratches are easy to deal with and don't mean much if you barrier coat then coat with vc performance epoxy or micron trilux 33. However you need to consider mill thickness and existing  delrin clearance. Heavily sand existing finish and previous layers off the strut to gain some clearance. Barrier coat and Trilux are thick. I've done a few fresh water wet sailed 24's. Ideally the keel is completely redone then new delrins fit to new shape. 

 Your lower delrin has rough spots. Check closely and look for heavy crazing. Tight does not always mean it is in decent shape. You should plan for new delrins top, bottom and verticals in the near future.

 Can you take a picture of your mast crane?

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1 hour ago, Karukera said:

@PeterRoss some images. Probably due to pounding against the front there are a crack almost half the keel length in front, see drawing. How does the keel profile look, is it risk of it splitting?

 

20210929_162645.jpg

20210929_163830.jpg

Leading edge crack.jpg

20210929_160917.jpg

It clearly needs some work but aren't you pointing out the kelp cutter track?  I see now...it's a crack on one side of the kelp cutter. 

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@Karukera

 You have the keel out of the boat?

 Kelp cutter groove does not look horrible,, very typical.. Plastic putty spreaders fit in the kelp cutter groove nicely with cutter removed or raised above damage. Use the putty spreader as a dam. Fill damage with putty on both sides at same time. If the repair is longer, find something similar in groove thickness to use as a dam. Putty spreaders release well. I put them in thin side out.

 It you have the Keel out, lay it on its side to let water pour out. Lay it on both sides, water finds voids to hide in. I've stored them upside down for a winter only to find a pint pour out from each when rolling upright. 

 Again, if keel is out, do all the delrins and develop a method of raising and lowering that limits the trailing edge damage.

 Your trailing edge is crying for an internal spline as described earlier. The method allows you to rebuild that trailing edge with strength, not just putty.

 You might be able to get away with woven carbon tape from an online supplier but avoid unidirectional material. 

 

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5 hours ago, PeterRoss said:

@Karukera

 You have the keel out of the boat?

 Kelp cutter groove does not look horrible,, very typical.. Plastic putty spreaders fit in the kelp cutter groove nicely with cutter removed or raised above damage. Use the putty spreader as a dam. Fill damage with putty on both sides at same time. If the repair is longer, find something similar in groove thickness to use as a dam. Putty spreaders release well. I put them in thin side out.

 It you have the Keel out, lay it on its side to let water pour out. Lay it on both sides, water finds voids to hide in. I've stored them upside down for a winter only to find a pint pour out from each when rolling upright. 

 Again, if keel is out, do all the delrins and develop a method of raising and lowering that limits the trailing edge damage.

 Your trailing edge is crying for an internal spline as described earlier. The method allows you to rebuild that trailing edge with strength, not just putty.

 You might be able to get away with woven carbon tape from an online supplier but avoid unidirectional material. 

 

@Peter RossI have the keel out. Seems dry, according to seller it has been dry sailed and then on land for 2 years. There were no water i the foam I pulled out near the bulb.

Where do you allow water to drain?, the screw holes at the top is closed in the bottom.
My top screws only goes 8-10 mm down the threads, the threads are 15 mm long. Feels short!?, how long are your screws so that I can confirm that mine are correct. Do you know what threading it is 3/8 UNC or UNF?, thinking of cleaning the threads.

Removed material 1 cm into the trailing edge then applied Epoxy, first non-thicked to suck in to the keel carbon and the thicken to fill the void. I also pushed in two sheets of 165 gram fiberglass folded in the middle, so total of 4 layers in the gap. Fiberglass has the same strength as carbon so shall be good enough, a little more flex but shouldn't matter.  
Would say that the trailing edge has a bad construction, there is only 1 mm carbon edge before the foam starts. The foam even sticks out in some places. Have Melges changed the construction on newer boats adding i spine as we do now?

The crack iw inside the kelp cutter track, see my drawing. But hopefully it is just some millimeter deep, saw on top that the carbon continues some centimetres so shall not be a issue if it doesn't continue to split. 

One of the delrin screws underneath is sticking out, don't know the reason yet. Is it metal threads in the hull or just plastic threads?

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@Karukera The water enters through the vertical delrin holes. It can also find its way in some of those cap holes, not sure how but it's water, it will find a way in. Laying keel on its side let's any water run out the delrin holes. The vacuum chamber hose can pull through during holes also, tape other holes. Don't recall thread info.

 The reason I use carbon is the keel strut is carbon. Other glass materials have a negative expansion rate to carbon. Carbon and water both expand in cold. My hopes were to keep enough water out to avoid ice overcoming the carbon trailing edge.

 Are the edges of the lower delrin green? Did you inspect for heavy crazing?  No, the lower delrin does not have threaded inserts. 

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@PeterRossdo you or someone else know the two Jotun/Neste Gelcoat (grey and white) color codes for the Melges 24?

 

No crazing in the lower delerin. Is there any risk of water entering into the boat through the threads for the lower delerin, or are they only in the plastic and not into the foam core?

 

Where do you vacuum suck out water inside the boat, have you drilled a hole through the inner laminate? 

 

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  • 5 weeks later...
3 hours ago, Bandersnatch said:

Does anyone have any numbers handy for clearances required to lift the boat off the keel? Looking at a gantry for the shed at home, yes will measure trailed height etc but some indication would be handy. 
 

thanks

I don't have the exact measurements as I need to do the same but it's got to be about two meters plus whatever distance the bulb is off the ground. 5' of draft, maybe 1.5' through the hull. 

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This may sound crazy but worked for my Hot Foot 20.

I was also no longer racing the boat at a high level  of competitiveness so figured I would  give this idea a try. I had damaged the leading and trailing edges of the keel raising,  launching etc.  I repaired it a couple  or times but eventually it took on enough water to split due to winter freezing.  I repaired and sealed everything  up and then had a crazy  idea.  I bot some water proof gorilla  tape that said it would stick underwater.  I covered the leading and trailing edges with the tape to protect from future  damage and to add another layer of water intrusion protection.  I did this with horizontal  strips about 2 inches long.  I really  had my doubts that this would work  and really expected the tape to fall off over a summer on my mooring ball.  To my surprise the tape was intact after 5 months underwater.  I did not have another freeze and splitting problem.  I also did not notice any change in performance  so fine for beer can club racing. The tape is easy  to apply  and you have to work at it a little to remove but not a problem to remove. I would not do this to a boat racing at top levels but did not regret doing it to my Hot Foot.  Actually should  have done it sooner.  Would have protected the leading and trailing edges. The clear  water proof Gorilla Tape is amazing.  

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