Seeking professional gelcoat peeling service off-site (South Coast)

[siravingmon]

Hi all,
I’ve just acquired an old Freedom 30 cat ketch with osmosis and I’m looking for someone who could peel the gel coat and sandblast it for me. Can anyone recommend someone reliable? The boat is located on the hard at Ridge Wharf (Wareham) but peeling is not a service they offer in-house so I need to bring someone in.

Simon

 

[Boathook]

Hi all,
I’ve just acquired an old Freedom 30 cat ketch with osmosis and I’m looking for someone who could peel the gel coat and sandblast it for me. Can anyone recommend someone reliable? The boat is located on the hard at Ridge Wharf (Wareham) but peeling is not a service they offer in-house so I need to bring someone in.

Simon

Welcome to the forum.

How bad is the osmosis. Do you really need to peel the gel coat.

Any pictures ? Need to be a fairly small file size to post here.

 

[siravingmon]

Thanks for the welcome
Quite a lot of blisters with most of them around 15 cm with some as big as 20 cm. They’re on the hull, the centre board and the rudder after the boat was left in the water for 10+ years by the previous owner.. I’ll have a go at shrinking some of the pictures I have tomorrow.

 

[wrr]

Although my hull cannot suffer from osmosis, being pitchpine, I have used the services of Symblast, whom I found very good, to remove decades of antifouling. I believe that they also peel gelcoat.

 

[Rappey]

You do realise that peeling the gelcoat does not stop the blisters from coming back or new ones forming ?
Dont do it..it cant be undone... unless you have more blisters than gelcoat just chisel or grind them out, epoxy fill and enjoy sailing with all the money you have saved ?

 

[wiggy]

I can not recommend Hayling Yacht Services, someone I know had a terrible time with them, result was strip of new epoxy, dry and re-apply.

 

[catalina1]

I have used Symblast , Done 5 years ago, no problems

 

[siravingmon]

Although my hull cannot suffer from osmosis, being pitchpine, I have used the services of Symblast, whom I found very good, to remove decades of antifouling. I believe that they also peel gelcoat.

Thanks for that

 

[siravingmon]

I have used Symblast , Done 5 years ago, no problems

Thanks!

 

[siravingmon]

I can not recommend Hayling Yacht Services, someone I know had a terrible time with them, result was strip of new epoxy, dry and re-apply.

Thanks - I’ve already been warned off them. Inadequate rinsing after peeling and sandblasting before drying/epoxying apparently

 

[siravingmon]

You do realise that peeling the gelcoat does not stop the blisters from coming back or new ones forming ?
Dont do it..it cant be undone... unless you have more blisters than gelcoat just chisel or grind them out, epoxy fill and enjoy sailing with all the money you have saved ?

Thanks for the warning. I have too many blisters to just chisel them out, I’ve been told by someone I trust. Still have to decide whether I just live with it or have it peeled/sandblasted/rinsed repeatedly/dried epoxied. Cost is obviosly a factor, as is the fact that the balsa core extends a bit below the waterline, but apparently the osmosis hasnt got into thel glass fibre and as I won't be using the boat until 2026 time is at least on my side for the drying process,

 

[Tranona]

Thanks for the warning. I have too many blisters to just chisel them out, I’ve been told by someone I trust. Still have to decide whether I just live with it or have it peeled/sandblasted/rinsed repeatedly/dried epoxied. Cost is obviosly a factor, as is the fact that the balsa core extends a bit below the waterline, but apparently the osmosis hasnt got into thel glass fibre and as I won't be using the boat until 2026 time is at least on my side for the drying process,

Gel coat peeling has gone out of fashion, primarily because it is economically not viable on the sorts of boats like yours. Not sure why you are being advised that the osmosis has "not got into the glass fibre". It is where it comes from and has been in the moulding from the day it was laid up. The blister are caused by styrenes reacting with the water coming in from the porous gel coat. The best you can do is to open up the blisters and let the fluid out. Almost impossible to dry it out to the point where it is worth replacing the gel coat - which is what you will need to do after peeling.

The best you can do is have it blasted to open up the blisters and remove any loose gel coat, then fill and epoxy. That is still a huge amount of work.

For blasting I have used Symblast twice and OK, but for my last job I used Dan southerndustlessblasting.uk who now does all the blasting in our club (Poole Yacht Club)

 

[siravingmon]

Many thanks for that and for the recomendation.
Sorry I wasnt clearer about how deep the osmosis has penetrated. I've been told that it appears to be quite shallow, penetrating the outer layers of polyester resin but probably not yet going as deep as the underlying glass fibre/polyester mix, with the caveat that initial peeling should be exploratory to see how deep the osmosis has gone (and if it's got into the underlying glassibre layer, not to proceed with it due to the huge expense).
I could I just go for your suggested sandblasting and individual grinding instead, although there are scores of blisters (about 10 to 30 cm apart )and as the moisture levels in the hull are high, there wiil be more blisters on the way, so only removing the gelcoat completely might allow the hull to dry out enough to stop future issues. Then again it sounds like it might not…
So taking on board what you and others are saying, it seems like I should perhaps just live with the osmosis and accept that it will shorten the life of the boat. I’ll be keeping it out of the water most winters so hopefully that will at least slow the process down a little bit (I acquired the boat knowing about the issue and the possible consequences).

 

[Boathook]

Just grind out the biggest blisters and fill with thickened epoxy after they have been allowed to dry. If you can get to the boat occasionally to carry this work out they will soon reduce in number !

 

[Tranona]

Many thanks for that and for the recomendation.
Sorry I wasnt clearer about how deep the osmosis has penetrated. I've been told that it appears to be quite shallow, penetrating the outer layers of polyester resin but probably not yet going as deep as the underlying glass fibre/polyester mix, with the caveat that initial peeling should be exploratory to see how deep the osmosis has gone (and if it's got into the underlying glassibre layer, not to proceed with it due to the huge expense).
I could I just go for your suggested sandblasting and individual grinding instead, although there are scores of blisters (about 10 to 30 cm apart )and as the moisture levels in the hull are high, there wiil be more blisters on the way, so only removing the gelcoat completely might allow the hull to dry out enough to stop future issues. Then again it sounds like it might not…
So taking on board what you and others are saying, it seems like I should perhaps just live with the osmosis and accept that it will shorten the life of the boat. I’ll be keeping it out of the water most winters so hopefully that will at least slow the process down a little bit (I acquired the boat knowing about the issue and the possible consequences).

Osmosis is a process, not an end state. The blisters and craters are formed by the liquid produced by osmosis breaking down the laminate. The underlying cause of the formation of the liquid is embedded in the laminate. You may well find after blasting there are more extensive areas of voids or where the laminate has broken down. Peeling does not help as that just removes the existing sounder gel coat which then needs replacing. Making good damage caused by osmosis is arguably the best you can do, followed by epoxy coating to make it more moisture resistant. In reality the "life" is unlikely to be changed. The laminate is so thick and heavy it will retain its structural integrity pretty much indefinitely. A boat's useful life is determined more by the bits that make it a usable boat than the strength and integrity of the hull. Look around any boatyard for evidence of this.

I think you have to accept that you are never going to be able to get the laminate dry enough to eliminate further osmosis. The best you can hope is to create a surface that minimises water passing through from outside, thus delaying the formation of blisters that need attention.

 

[siravingmon]

Thanks again. When you say “making good damage caused by osmosis is arguably the best you can do, followed by epoxy coating to make it more moisture resistant”, do you mean epoxy coating just the damaged/repaired areas or epoxying the whole hull over the gelcoat? I’m assuming the former but thought I’d better double check with you.

 

[Tranona]

The whole surface. The blasting will remove all previous coatings from thee complete area. Then fill and fair with an epoxy filler such as International Watertite then a 2 part epoxy coating such as International Gelshield. There are other similar products from other suppliers. If you are doing this yourself perhaps you need to do some research and maybe engage a surveyor to give you advice as to the best way to go about it. This is not a trivial job and will be costly in materials even if you do the labour so worth getting more knowledgeable advice than just the general advice here. Googling will lead you to plenty of advice and youtube on how others have gone about it.

 

[Elessar]

You do realise that peeling the gelcoat does not stop the blisters from coming back or new ones forming ?
Dont do it..it cant be undone... unless you have more blisters than gelcoat just chisel or grind them out, epoxy fill and enjoy sailing with all the money you have saved ?

Bad advice.
Peeling then blasting then drying (which you do by jet washing daily) followed by epoxy is a forever job if done properly.

 

[Elessar]

Osmosis is a process, not an end state. The blisters and craters are formed by the liquid produced by osmosis breaking down the laminate. The underlying cause of the formation of the liquid is embedded in the laminate. You may well find after blasting there are more extensive areas of voids or where the laminate has broken down. Peeling does not help as that just removes the existing sounder gel coat which then needs replacing. Making good damage caused by osmosis is arguably the best you can do, followed by epoxy coating to make it more moisture resistant. In reality the "life" is unlikely to be changed. The laminate is so thick and heavy it will retain its structural integrity pretty much indefinitely. A boat's useful life is determined more by the bits that make it a usable boat than the strength and integrity of the hull. Look around any boatyard for evidence of this.

I think you have to accept that you are never going to be able to get the laminate dry enough to eliminate further osmosis. The best you can hope is to create a surface that minimises water passing through from outside, thus delaying the formation of blisters that need attention.

This is complete nonsense. Wrong in so many ways I can’t be bothered to pick it apart. “The sounder Gelcoat” bit is particularly laughable.

 

[Iliade]

I cannot recall a boat sunk by osmosis. Patch repair, as and when you can be bothered, and enjoy sailing the boat. you'll probably be long dead and forgotten before the osmosis becomes actually dangerous.

Back in 1982 I was, to the best of my knowledge, the first person to plane the gelcoat off an osmosis affected hull. It cost me about 18 months of sailing time while it dried properly and was a near complete waste of time and effort and this on a lightly built 1/4 tonner. Unfortunately, I didn't patent the process...