what do do next after antifoul removal?

[chubby]

Setting: 32 year old GRP boat worth about 25K, not planning to change in foreseable future, wintered ashore each year.

eventually bit the bullet and got 25+ years of antifould blasted off to gel coat, previous layer of blakes epoxy ( the red brown one) at least 25 years old largely came off with the AF, not surprisingly some blisters, a bit like telling a bloke of my age you have grey hairs!

Presumably any osmosis may have been present for years.

A deluxe solution would be gel peel, rebuild with solvent free epoxy etc about 5-6K and loss of first half of next season.

A pragmatic solution of to fill the bad bits and odd dings and gelshield ( easier to apply and more tolerant of low temperatures) about 1K or less including albour and materials or less if I do some myself.

A minmalist approach would just be to fill the bad bits, antifoul primer, paint and go sailing taking the view that osmosis is over rated and boats dont actually disintergrate under you and a 1970s hull is probably over specified and has plenty of reserve strength.

What do forumites suggest allowing for value of boat etc, a bit like respraying an old car costing about 25% of the value of the car or just put up with a few rust patches?

 

[SvenglishTommy]

A minmalist approach would just be to fill the bad bits, antifoul primer, paint and go sailing taking the view that osmosis is over rated and boats dont actually disintergrate under you and a 1970s hull is probably over specified and has plenty of reserve strength.

I would definately take that approach, especially as you're not intending to sell in the near future. You can pour so much money into old boats, and you'll never get it back. I reckon I've spent 10K on my boat, which is worth about 10K, over the last six years and the boat is still worth 10K.

 

[Elessar]

Setting: 32 year old GRP boat worth about 25K, not planning to change in foreseable future, wintered ashore each year.

eventually bit the bullet and got 25+ years of antifould blasted off to gel coat, previous layer of blakes epoxy ( the red brown one) at least 25 years old largely came off with the AF, not surprisingly some blisters, a bit like telling a bloke of my age you have grey hairs!

Presumably any osmosis may have been present for years.

A deluxe solution would be gel peel, rebuild with solvent free epoxy etc about 5-6K and loss of first half of next season.

A pragmatic solution of to fill the bad bits and odd dings and gelshield ( easier to apply and more tolerant of low temperatures) about 1K or less including albour and materials or less if I do some myself.

A minmalist approach would just be to fill the bad bits, antifoul primer, paint and go sailing taking the view that osmosis is over rated and boats dont actually disintergrate under you and a 1970s hull is probably over specified and has plenty of reserve strength.

What do forumites suggest allowing for value of boat etc, a bit like respraying an old car costing about 25% of the value of the car or just put up with a few rust patches?

don't gelshield it if it's wet, it will encourage bubbles. Remember it is as wet in the non bubbly bits between the bubbles.

so it's 1 or 3.........

you can part DIY 1 though.

 

[alahol2]

I got to the point you are at about 15 years ago with a previous boat. I decided to go the 'middle' way. I went over the gelcoat with an orbital sander to key it up. Filled any dints and scrapes. Used Blakes SFE200(?) (grey and cream) as, at the time, it seemed to have fewer temperature restrictions. I only put three coats on and it was very easy to do.
I have seen the boat again recently and it is still looking OK with no obvious blisters that I can see. Mind you, it may well have been OK without the epoxy, who can tell?

 

[dmmbruce]

Chubby, please can you say, why did you bother in the first place?

Did you have a fit of shiny bottom racey madness, or did you fall for the sales talk of the A/F commercial interests?

Is it possible that you were inviting work and expense for no particular reason?

Sorry for the question, but I have wondered about doing this on various boats and have never, in the end, done so.

Mike

 

[chubby]

About 33% of the antifoul was flaking off and had done for years, each season i planned to strip it for the last 10 years, i would have an hours scrapping, get fed up and think blow it, patch prime the worst, pop on some af and not worry once back in the water, any reduction in speed is insignificant for a motorsailor with a three blade prop that tows the dinghy. What happened th is year? I came down to the yard just to see where they had put her, not by the fence next to trees full on craping birds, found the af removal van was there, got talking to the guy, unusually for me made a rash decision, now 25 years of built up antifoul has suddenly gone. The danger is you get dragged into a bigger job than you bargined for, hence the post to see how much is really needed!

 

[chubby]

I got to the point you are at about 15 years ago with a previous boat. I decided to go the 'middle' way. I went over the gelcoat with an orbital sander to key it up. Filled any dints and scrapes. Used Blakes SFE200(?) (grey and cream) as, at the time, it seemed to have fewer temperature restrictions. I only put three coats on and it was very easy to do.
I have seen the boat again recently and it is still looking OK with no obvious blisters that I can see. Mind you, it may well have been OK without the epoxy, who can tell?

As an enthusiatic follower of your tightwad style of cruising that is music to my ears, i think one can be too perfectionist about these things when dealing with boats of a mature age. We have passed flying fox and candice many times at sea or seen you at anchor, usually in newtown!

 

[alahol2]

... i think one can be too perfectionist about these things when dealing with boats of a mature age. We have passed flying fox and candice many times at sea or seen you at anchor, usually in newtown!

Yes, we do seem to spend an inordinate number of weekends in Newtown, it's just the right balance between a good sail for me and a 'boring' slog for the wife. We have seen you around.
I should have added to my previous post that a few years ago I scraped the bottom of FF. I took 2 winters to do it, starboard one year port the next. As I was of more mature years too, I decided to forego the chance to epoxy it and took the easy way, primer and A/F.
Good luck.

 

[chubby]

Yes, we do seem to spend an inordinate number of weekends in Newtown, it's just the right balance between a good sail for me and a 'boring' slog for the wife. We have seen you around.
I should have added to my previous post that a few years ago I scraped the bottom of FF. I took 2 winters to do it, starboard one year port the next. As I was of more mature years too, I decided to forego the chance to epoxy it and took the easy way, primer and A/F.
Good luck.

Excellent, and I bet you dont notice any problems, is this bottom treatment thing just to stimulate the EU economy?

 

[GrahamM376]

I would get some meter readings taken to see how much moisture is in the hull and get an idea how long it will take to dry out. If not too many blisters, I would power wash them a few times, preferably with hot water and then fill them. If hull dry enough by end of winter then gelshield it, otherwise just antifoul.

 

[chubby]

I would get some meter readings taken to see how much moisture is in the hull and get an idea how long it will take to dry out. If not too many blisters, I would power wash them a few times, preferably with hot water and then fill them. If hull dry enough by end of winter then gelshield it, otherwise just antifoul.

What actually happens if you just prime and antifoul it?

I suspect nothing much.

My understanding is that boats don`t soak up water like blotting paper and disintigrate like ripe camembert, rather a 20 year old expoxy coating was 10 years beyond sell by date, any water may have been there for years, hulls only soak up 2-3% of their weight in water and structural failure is rare and unlikely in a heavily built 30+ year old boat.

I think the pragmatic approach is to leave it to breathe over the winter and do a moisture check in the spring, if dry enough then gelshield and antifoul. If not dry then just primer and antifoul. To be honest I have been patch priming flaky bits with primer for years and the bottom looked like a patchwork quilt, now it will at least be more uniform and only have one years thickness of paint.

I guess the thing not to do is to gelshield if the moistuere too high, even then what actually happens? The odd blister or will the whole thing peel off like a cooked tomato skin, even if so can`t be any worse other than the effort of putting it on.

Once back in the water forget about it. Do we worry too much about a non or self made problem?

Anything wrong with that approach?

 

[Colvic Watson]

I got a quote for Coppercoat for our 35 footer, it was £1900 including the AF removal; what surprised was the amount of filling and fairing they were prepared to do as part of the preparation for the Coppercoat; bearing in mind it eliminates antifouling for ten wonderful years I think it made it worth it. I know you've already done the removal and your underwater area is probably less than ours so you'd get a nice shiny smooth bottom for about £1200. Cheaper than plastic surgery

 

[GrahamM376]

I think the pragmatic approach is to leave it to breathe over the winter and do a moisture check in the spring, if dry enough then gelshield and antifoul. If not dry then just primer and antifoul. To be honest I have been patch priming flaky bits with primer for years and the bottom looked like a patchwork quilt, now it will at least be more uniform and only have one years thickness of paint.

I guess the thing not to do is to gelshield if the moistuere too high, even then what actually happens? The odd blister or will the whole thing peel off like a cooked tomato skin, even if so can`t be any worse other than the effort of putting it on.

I got fed up with flaking antifoul so scraped it all off and Gelshielded, last winter. Gelshield is easy to apply, it's the scraping off that's hard work. Working in the Algarve winter sun, the moisture readings showed it was dry enough to epoxy without prolonged drying.

Our first boat, a Centaur, had been epoxied over a damp hull before we purchased and it didn't take long for blisters to develop and some epoxy to come off. It took a long time to dry out once the gel removed. An expensive PITA.