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How to remedy corroded mast base?


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I am intending to buy this Catalina 34, late 80s. It all checks out, except the base of the mas has some corrosion. 

1) What are the dangers? is this just cosmetic?

2) How should I fix this?

 

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Appears to be cosmetic only. Probably caused by water trapped inside the mast section. There should be a drain hole, but most are easily plugged and/or no drain to start with. Repair - strip off bubbled paint, clean/etch aluminum, re-prime with appropriate paint systems. Color paint if you wish

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I'd sure poke at the corrosion with a sharp awl and see if I could poke a hole in the mast. The corrosion might well be worse on the inside of the mast wall and the outside in better shape however. If it is really bad you can cut off a few inches and built up the step a few inches higher.

Did you get it surveyed and if so, what did the surveyor say?

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Cannot speak to your specific case, but my boat showed signs of similar paint bubbling and corrosion at the mast base at pre-purchase inspection. Being young(er) and (more) foolish (than I am now) I crossed my fingers and paid-up.

Subsequently, I pulled the mast and sanded off all the paint. Underneath the paint, in the corroded areas, the damage to the mast was minimal... slight surface pitting / corrosion, but not sufficient to cause any alarm with a couple of shipwrights and an Insurance Surveyor who inspected...

If you do strip the mast and repaint, it is worth putting effort into cleaning the corroded areas very thoroughly or the paint will most likely just bubble again.

YMMV

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I had a corroding deck stepped mast foot. About 35 years of service. Knew it was getting thinner with time. One blustery day the rig got a little wobbley. Lo, the base had mushed 2 inches quite elegantly. I wanted a new rig anyway. The local rig guy, Buzz, could have done any number of sleeve tricks to extend the life of the old mast if I had so wanted. He had easily done such on another boat I had. 

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The mast foot and mast step  are high maintenance

this is one of the reasons why  you pull the mast every  couple years 

also keep an eye on goosenecks , mast partners an any mechanical fastened dissimilar metal 

 

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IMHO you would be best off to pull the rig and thoroughly inspect the foot of the mast, the cast aluminum mast step and the material it sits on.
It is plain to see that water has been standing inside the rig and as Longy pointed out it is likely cosmetic. However, and I do not know the specific practices Catalina used to form the stringer the step is standing on/fastened to..... but if they used a piece of plywood and glassed over it, the wood itself may be compromised.
And again as Longy pointed out, the drain holes are likely clogged and you want to remedy that as well, probably enlarging them and sealing any exposed materials that may wick water, become saturated and turn or has already turned spongy.

Probably not what you wanted to hear but best to pull the rig so it can be properly inspected in any event. 

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12 hours ago, Migus said:

I am intending to buy this Catalina 34, late 80s. It all checks out, except the base of the mas has some corrosion. 

1) What are the dangers? is this just cosmetic?

2) How should I fix this?

 

Image 1601.png

Well first is to remove and inspect, needs to be taken down to bare metal and sealed. If chipped, pitted on the bottom? cut off a inch so its clean and undamaged.

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10 hours ago, Zonker said:

I'd sure poke at the corrosion with a sharp awl and see if I could poke a hole in the mast. The corrosion might well be worse on the inside of the mast wall and the outside in better shape however. If it is really bad you can cut off a few inches and built up the step a few inches higher.

Did you get it surveyed and if so, what did the surveyor say?

Lower your purchase price to pay for the repair. Anything you find wrong should get you a lower price. Too many things wrong then give it a pass and look for another boat in better shape.

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47 minutes ago, Benytoe said:

Well first is to remove and inspect, needs to be taken down to bare metal and sealed. If chipped, pitted on the bottom? cut off a inch so its clean and undamaged.

If you trim the bottom, make up the distance by raising the mast step. A plate of G-10 does a great job. 

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Thanks for the very helpful replies! 
If I purchase this boat I will pull the mast and do a thorough inspection with a surveyor. The mast will be pulled anyway because I would have to ship this boat to my port. 

This is my first keelboat, and the feedback I was looking for was whether it may be cosmetic, in which case, how to I repair? Or if it was something definitely costly/problematic, that I should stay away from (for instance, I would stay away from any deck delamination requiring recoring).

 

Thanks!

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1 hour ago, Migus said:

Thanks for the very helpful replies! 
If I purchase this boat I will pull the mast and do a thorough inspection with a surveyor. The mast will be pulled anyway because I would have to ship this boat to my port. 

This is my first keelboat, and the feedback I was looking for was whether it may be cosmetic, in which case, how to I repair? Or if it was something definitely costly/problematic, that I should stay away from (for instance, I would stay away from any deck delamination requiring recoring).

 

Thanks!

Have you gone to contract?
Is the contract dependent on passing survey? They usually are.
Why not ask the seller to unstep the rig for further inspection?
If it is okay, and you intend to buy the boat with only this issue raising a red flag, then offer to reimburse the seller if there is no real issue and you go to closing.
As Zonker said, it is the inside that you cannot be sure of.
And as Longy said, a G10 spacer if the remedy is loping 1.5 inches or so off the bottom of the extrusion.
In any event, don't just roll the dice. The seller should understand this and since his/her goal is to get to closing, you do have a bit of leverage.

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7 minutes ago, quod umbra said:

Have you gone to contract?
Is the contract dependent on passing survey? They usually are.
Why not ask the seller to unstep the rig for further inspection?
If it is okay, and you intend to buy the boat with only this issue raising a red flag, then offer to reimburse the seller if there is no real issue and you go to closing.
As Zonker said, it is the inside that you cannot be sure of.
And as Longy said, a G10 spacer if the remedy is loping 1.5 inches or so off the bottom of the extrusion.
In any event, don't just roll the dice. The seller should understand this and since his/her goal is to get to closing, you do have a bit of leverage.

No. If the buyer wants to pull the rig, that is done at the buyer’s expense same as any other survey expenses. As to price reductions due to survey, all is negotiable but degradation clearly visible on a 40 YO boat is generally in the “as presented” and unless it is a significant survey finding, not picking an old boat is likely to get you a canceled sale if you get too greedy.  

All depends on the motivation of the seller. 

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1 hour ago, Innocent Bystander said:

No. If the buyer wants to pull the rig, that is done at the buyer’s expense same as any other survey expenses. As to price reductions due to survey, all is negotiable but degradation clearly visible on a 40 YO boat is generally in the “as presented” and unless it is a significant survey finding, not picking an old boat is likely to get you a canceled sale if you get too greedy.  

All depends on the motivation of the seller. 

Thanks guys! 

Yes, the plan is to have an offer with contingencies on the survey. The mast will be pulled anyway for inspection and transportation, and the surveyor is aware. If the mast is in a bad shape, or any other piece of the survey being negative, I will either negotiate or back out. 

If the transaction moves forward, the boat gets on a truck, otherwise the seller owns the cost of stepping back the mast and relaunching the boat.

Does that sound fair to you guys?

Thanks for all the support. 

 

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5 hours ago, longy said:

If you trim the bottom, make up the distance by raising the mast step. A plate of G-10 does a great job. 

thats what we did exactly, better then new and it carried us to Hawaii on the transpac

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47 minutes ago, Migus said:

Thanks guys! 

Yes, the plan is to have an offer with contingencies on the survey. The mast will be pulled anyway for inspection and transportation, and the surveyor is aware. If the mast is in a bad shape, or any other piece of the survey being negative, I will either negotiate or back out. 

If the transaction moves forward, the boat gets on a truck, otherwise the seller owns the cost of stepping back the mast and relaunching the boat.

Does that sound fair to you guys?

Thanks for all the support. 

 

Do you have a broker?  Survey is normally from slip to slip (if in the water) and returned to condition when presented to the buyer/buyer’s surveyor. Sea trial is normally done at the time of survey and cost to launch and recover belongs to the buyer. 
 

 You want me to sign a contract that says you can take my boat out of the water, take it apart and then walk away leaving me with any costs to return it to how it was?  Good luck. As a seller, I would not sign that contract. What about having a professional rigger give an estimate to repair the mast step given how it looks (which isn’t terrible). Make that a withhold /escrow condition (seller will cover repairs to the mast step up to a value of xxx). If the survey reveals massive problems, walk away or renegotiate. 
 

In general, advice to nit pick the survey is poor advice. You are expected to assess the condition of the boat as presented and the survey is all about damage/deterioration not obvious to the intelligent buyer. Your offer should consider the boats condition as presented and obvious. If the engine is listed as “inoperable” in the listing, you aren’t going to get it fixed by the seller based on a survey report. If electronics are installed and not noted to be inop, dead displays would be a survey finding to discuss. 

You can execute any contract that you and the seller sign. Good sellers will represent the boat honestly and truthfully.  Greedy buyers often get told to GTFO when their demands are out of line. Desperate sellers may sign anything.  
 

I bought a boat cheap from a desperate seller We agreed at the time of the offer that minor survey findings would not be negotiated the survey would be a settle within 3 days/walk decision.  Of course, I could have tried to negotiate post survey but would have done it gently through the seller’s broker and only if a safety/structural funding came out and I still wanted that boat.

 

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25 minutes ago, Innocent Bystander said:

Do you have a broker?  Survey is normally from slip to slip (if in the water) and returned to condition when presented to the buyer/buyer’s surveyor. Sea trial is normally done at the time of survey and cost to launch and recover belongs to the buyer. 
 

 You want me to sign a contract that says you can take my boat out of the water, take it apart and then walk away leaving me with any costs to return it to how it was?  Good luck. As a seller, I would not sign that contract. What about having a professional rigger give an estimate to repair the mast step given how it looks (which isn’t terrible). Make that a withhold /escrow condition (seller will cover repairs to the mast step up to a value of xxx). If the survey reveals massive problems, walk away or renegotiate. 
 

In general, advice to nit pick the survey is poor advice. You are expected to assess the condition of the boat as presented and the survey is all about damage/deterioration not obvious to the intelligent buyer. Your offer should consider the boats condition as presented and obvious. If the engine is listed as “inoperable” in the listing, you aren’t going to get it fixed by the seller based on a survey report. If electronics are installed and not noted to be inop, dead displays would be a survey finding to discuss. 

You can execute any contract that you and the seller sign. Good sellers will represent the boat honestly and truthfully.  Greedy buyers often get told to GTFO when their demands are out of line. Desperate sellers may sign anything.  
 

I bought a boat cheap from a desperate seller We agreed at the time of the offer that minor survey findings would not be negotiated the survey would be a settle within 3 days/walk decision.  Of course, I could have tried to negotiate post survey but would have done it gently through the seller’s broker and only if a safety/structural funding came out and I still wanted that boat.

 

Great thoughts, and they make a lot of sense. Thanks!
No broker. 

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While I do not wholly disagree with I.B., everything can be negotiated. Anyone who out of hand dismisses certain strategies in the negotiation of buying or selling a boat is limiting what the known possibilities are.
Disclaimer, four or so decades ago I was in that biz. Bottom line is if you do not ask, you will never know.

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37 minutes ago, Migus said:

Any chance you can share a picture? Thanks!

I will look for it. it was really easy to cut when mast was out and laying on stands. while mast was out we rewired the whole thing, changed deck and masthead lights to LED and replaced spreader bolts to bigger and stronger. We also riveted a PVC tube inside the mast where all the wiring was then run. It banged inside the mast before. now its clean, quiet and strong. 

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Let me expand on that a wee bit if I may. 

The mast issue is right out there in the open, plain to see. I.B.'s slant is this is to be expected due to age of boat and price reflects that. That may or may not be correct since we do not know what the boat is actually worth (comps) and the asking price.
So seller knows of the corrosion issue and chose not to address it prior to selling it...… next owner's problem. That said I think you could press him/her to yank the rig with the understanding you will reimburse him IF you follow through on the purchase. If the seller didn't wish to be exposed in such a way, he would have addressed the issue and you would either be none the wiser or he/she would be telling you about the work done to keep her up to snuff. Also IF you walk away over the rig, the seller has to take that into consideration.....'maybe I should have fixed that.... maybe I should fix it now before it screws another deal?"
Last point, every seller has "beer goggles" to some degree. There boat is both beautiful and great. The price often reflects that sentimental view. You as the possible future owner have to bear that in mind and not shy away from knowing just what you are buying and how much you are paying both at the closing and in order to get her back up to par.

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21 minutes ago, Migus said:

Great thoughts, and they make a lot of sense. Thanks!
No broker. 

it also depends on how much the boast is going to cost? Paying in the thousand dollar range for a survey makes sense on a expensive boat but not on a cheap one. Also something I did on my last boat that I bought. Since I paid for the survey haul out and got a really good report back telling me to buy it. It made sense to have the bottom done since it was already out of the water in the boat yard. I agreed to buy it so all was good.

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3 minutes ago, Benytoe said:

I will look for it. it was really easy to cut when mast was out and laying on stands. while mast was out we rewired the whole thing, changed deck and masthead lights to LED and replaced spreader bolts to bigger and stronger. We also riveted a PVC tube inside the mast where all the wiring was then run. It banged inside the mast before. now its clean, quiet and strong. 

That's very useful, since I will have the mast on stands for a few days. I intend to replace the masthead like, deck flood light, and install a wind instrument. I will copy your riveting idea.

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7 minutes ago, quod umbra said:

Let me expand on that a wee bit if I may. 

The mast issue is right out there in the open, plain to see. I.B.'s slant is this is to be expected due to age of boat and price reflects that. That may or may not be correct since we do not know what the boat is actually worth (comps) and the asking price.
So seller knows of the corrosion issue and chose not to address it prior to selling it...… next owner's problem. That said I think you could press him/her to yank the rig with the understanding you will reimburse him IF you follow through on the purchase. If the seller didn't wish to be exposed in such a way, he would have addressed the issue and you would either be none the wiser or he/she would be telling you about the work done to keep her up to snuff. Also IF you walk away over the rig, the seller has to take that into consideration.....'maybe I should have fixed that.... maybe I should fix it now before it screws another deal?"
Last point, every seller has "beer goggles" to some degree. There boat is both beautiful and great. The price often reflects that sentimental view. You as the possible future owner have to bear that in mind and not shy away from knowing just what you are buying and how much you are paying both at the closing and in order to get her back up to par.

I agree with your points. The only correction is that, yes, the seller knows the corrosion problem, but doesn't see it as a problem - she sees it as cosmetic only (which could very well be). The contingency is only if the surveyor finds it to be a more serious issue beyond cosmetic.

Thanks! You guys are helping me tremendously.

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Of course she thinks it cosmetic! LOL

You cannot take that risk.
Worked on boats my whole life, it is just a picture on a website...… but I would be hard pressed to conclude it is only cosmetic. What it is, is symptomatic and that needs to be fully investigated. Seller needs to understand that and not just flip you off.
Best of luck.
Enjoy your Evening

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Does this spar have any holes in it? Fiber optic cameras that display thru your phone are common - and a LOT cheaper than pulling the rig. A view of the area from the inside will reveal most of the hidden problems. I just got one such that only needs a 3/8" hole & is 6 ft long. If there is a big problem, you will see the white aluminum corrosion product all over - maybe even the pasty white jello formed by corrosion in/under water

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By the way, guys, this will come up to a total of $40k, including prep, pulling the mast, shipping, remasting, tuning, launching. I know boat prices are very subjective, but, assuming this 1989 Catalina 34 is in great shape (albeit without much electronics, winter cover nor cradle), what do you think of this total cost?

 

Thanks! Mig

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20 hours ago, longy said:

Does this spar have any holes in it? Fiber optic cameras that display thru your phone are common - and a LOT cheaper than pulling the rig. A view of the area from the inside will reveal most of the hidden problems. I just got one such that only needs a 3/8" hole & is 6 ft long. If there is a big problem, you will see the white aluminum corrosion product all over - maybe even the pasty white jello formed by corrosion in/under water

Thank you so much! I didn't have a camera but the mast will be pulled.

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25 minutes ago, Migus said:

Thank you so much! I didn't have a camera but the mast will be pulled.

That is the better idea. I found the corrosion and thinning was precisely between the shoe and mast extrusion. A camera inside would tell nothing. 

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On 2/16/2021 at 2:31 PM, Migus said:

Any chance you can share a picture? Thanks!

I can't find it, I must have deleted it. I had a lot from the project and cleaned up my lap top. It was recommended by the rigger and easy. marked a line around the base about a inch from the bottom where the metal is not damaged and cut with a big hack saw, sanded the cut smooth with a file then painted with a sealer.

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12 hours ago, sidmon said:

Cut it to where the good metal starts, and fabricate a G10 fiberglass pedestal of the appropriate height...

Be alert

If you use g10 instead of an aluminum step you no longer have an electric connection ... lightning earth 

 

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Wouldn't it just be easier to get the exact height/length right if you sleeved it.  There has to be quite a bit of that mast section available to cut off a certain amount of the bottom and add back the same amount with an internal sleeve.

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46 minutes ago, gkny said:

Wouldn't it just be easier to get the exact height/length right if you sleeved it.  There has to be quite a bit of that mast section available to cut off a certain amount of the bottom and add back the same amount with an internal sleeve.

Easier?

I don't think so.

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1 hour ago, gkny said:

Wouldn't it just be easier to get the exact height/length right if you sleeved it.  There has to be quite a bit of that mast section available to cut off a certain amount of the bottom and add back the same amount with an internal sleeve.

Making up 1.5 inches, G-10 is a great option. But if you are talking much more than that sleeving is probably your only real option.
It isn't all that complicated. You used a piece of the same extrusion, cut it long diagonally and insert/afixit to both halves.

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This isn't wood. Cut the ends 90 degrees so that they can butt up against each other with no sheering loads. You want a straight transfer of compression loads. Splice pieces should just keep the two pieces in alignment

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On 2/17/2021 at 11:06 AM, Migus said:

By the way, guys, this will come up to a total of $40k, including prep, pulling the mast, shipping, remasting, tuning, launching. I know boat prices are very subjective, but, assuming this 1989 Catalina 34 is in great shape (albeit without much electronics, winter cover nor cradle), what do you think of this total cost?

 

Thanks! Mig

Current Retail Value Range $26,700-$29,700
120th edition.
Fair Market Value Adjusted for BUC Condition in the Great Lakes & Midwest $27,000-$30,000
Replacement Value $201,500

 

Above BUC condition Has had above average care and equipped with extra electrical and electronic gear Plus 10-15%
BUC Condition Ready for sale requiring no additional work and normally equipped for its size No Adjustment Necessary
Fair Requires usual maintenance to prepare for sale Minus 10-20%
     
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11 hours ago, slug zitski said:

Be alert

If you use g10 instead of an aluminum step you no longer have an electric connection ... lightning earth 

 

Run a ground wire...

 

 

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14 hours ago, longy said:

This isn't wood. Cut the ends 90 degrees so that they can butt up against each other with no sheering loads. You want a straight transfer of compression loads. Splice pieces should just keep the two pieces in alignment

I was referring to the inner piece, not the outer.

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Got a 1972 Islander 36 and the mast has never been pulled.  It's the Lefiell thin wall mast made of swaged anodized aircraft aluminum and there was contact corrosion at the base which was a concern but I drilled a drain hole after purchase in 1989 and it looks the same 40 years later.  Been surveyed several times for insurance purposes and the surveyors all say the corrosion has bonded the mast to the aluminum step so it's actually stronger than manufactured and to pull the mast would involve heavy work with SawsAlls, trimming and a G10 spacer which would probably be weaker than the present corroded mast/shoe interface.  I've had to replace spreaders due to tip corrosion at the SS rigging contact ends, but that's it.

There's more than visual inspection at the mast base, does the mast cant on tacks, when you bone the backstay does the forestay bone and the shrouds become all slack?  Any nasty grinding sounds at the mast base when beating in heavy seas?  Is the mast deck penetration getting beat up 'till it's a leaking mess?

Your photos imply a severe paint failure but paint is not structural.  I'd strip the mast base paint and poke around with an ice pick  and if things seem solid repaint with an etching primer followed by rustoleum aluminum paint.  My surveyors all pointed out yep the mast step is corroding slowly but I'll die before it breaks free.  Alternatively I could spend the 15 grand for a mast pull and mast base repair etc. so a future owner has another 50 years of  comfort. Doesn't pen out if you're selling a boat and isn't a factor if you're buying  a boat  with a a mast base that is acceptable.

BTW the idea that a G-10 insert as an insulator is a lightning risk is bullshit.  I've got a 2guage wire directly from the mast base to a keel bolt and it's kept me from lightning damage for 40 years although I've never been struck <g>.

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On 2/18/2021 at 5:11 PM, SloopJonB said:

IME BUC numbers are meaningless.

I have no idea what your experience is.  But, I have a metric crap load of clients who find the data very useful when proceeding with the purchase of a used yacht.

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17 hours ago, axolotl said:

 

BTW the idea that a G-10 insert as an insulator is a lightning risk is bullshit.  I've got a 2guage wire directly from the mast base to a keel bolt and it's kept me from lightning damage for 40 years although I've never been struck <g>.

Well now you've jinxed it. Please send out a general alert the next time you are on the water so we can all stay home!

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On 2/18/2021 at 8:26 AM, slug zitski said:

Be alert

If you use g10 instead of an aluminum step you no longer have an electric connection ... lightning earth 

 

The step is currently screwed into a GRP box section - no electrical continuity from the factory

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23 hours ago, axolotl said:

a G10 spacer which would probably be weaker than the present corroded mast/shoe interface. 

At 60,000 lbs compression load, its not an issue.

A common remedy on old Pearsons.

 

 

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Listen to the guy who said, ' check the goose-neck' (where  boom attaches to the mast) That is  a high stress area , which might also have aged interestingly.

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6 hours ago, Kraftwerk said:

Listen to the guy who said, ' check the goose-neck' (where  boom attaches to the mast) That is  a high stress area , which might also have aged interestingly.

And inspect the spreader roots 

high failure rate 

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6420F92C-D9C9-453B-A2F8-36FDF41C3935.jpeg

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Not that it matters here, but just as a quick update, the seller sold to the boat after we were already in agreement, 2 days before the survey. :( 
But I found another boat that in better shape, cheaper, the very next day :) 

Awaiting to schedule a survey now.

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