Blister repair

[grewvin1]

Have 22 blisters all in a 10ft radius. did knocked off the blister and water came out and small cavity showing glass weave approx. 1/32 deep. Best plan to make repair? Have read one suggestion to countersink area and fill with West epoxy. But need some guide on the complete repair. What to do after fill hole, coat with F/G or anything before replacing anitfoul.

 

[tpenfield]

Re: Blister repair

I am doing some blisters on my boat as well . . .

Open them up like you did . . . grind into any 'loose' layers and apply epoxy and fair to the surrounding gelcoat. Then you should really barrier coat before antifouling to keep the blisters away.

 

[grewvin1]

Re: Blister repair

Question Barrier coat is that a product name or create barrier coat with layer of fiberglass resin?

 

[a1964rn]

Re: Blister repair

Here's some good info on repairing gelcoat blisters. It calls for West System epoxy, but any good epoxy with cabosil thickener should be OK.
http://www.westsystem.com/ss/assets/HowTo-Publications/Fiberglass-Boat-Repair-and-Maintenance.pdf

 

[ondarvr]

Re: Blister repair

There are several factors that come into play when deciding on what method will be needed to do a blister repair.

There may be some reason this particular area blistered. It could be a repair that was done poorly, contaminated products used to build the boat, or other things. It could also be just the start of a much bigger problem that will eventually affect the entire hull bellow the water line.

If the blisters are caused by something that may only affect this area, then you can repair them and things may hold up well for a very long time. But if this is just the start of a much larger blister problem you either need to do the entire hull, or do nothing at all.

There is much more to blister repair than just digging them out and filling them, to do it right can be a rather long and costly project.

Pics will help a great deal in providing a good answer.

 

[tpenfield]

Re: Blister repair

Question Barrier coat is that a product name or create barrier coat with layer of fiberglass resin?

Barrier coat is usually an epoxy-based paint.. Interlux "Interprotect 2000" is a popular product for barrier coating.

I'll be barrier coating my boat, once I get the blisters filled. Keep in mind that they should be allowed to dry out for a 'while'. . . . I opened up the blisters on my boat last Fall, letting them dry out over the winter, will fill them this Spring.

 

[ondarvr]

Re: Blister repair

Just repairing (filling) the blisters doesn't complete the job, the problem is the blisters will likely continue to increase in number as time goes on if no further measures aren't taken, these are just the first blisters to show up, so in a few years you are right back where you started, with a blisterd hull.

The reliable method is to remove the gel coat and glass down to a depth where no more blisters are detected, then let it dry, or be force dried until as much moisture as possible can be removed. After that you rebuild the surface with epoxy and glass, or VE and glass (I think epoxy is better) back to its original thickness and shape, this involves a good deal of fairing and then painting. The owner needs to decide up front to either go all in, or do nothing, in between methods can yield disappointing results and almost be a waste of time and money.

 

[ondarvr]

Re: Blister repair

Have 22 blisters all in a 10ft radius. did knocked off the blister and water came out and small cavity showing glass weave approx. 1/32 deep. Best plan to make repair? Have read one suggestion to countersink area and fill with West epoxy. But need some guide on the complete repair. What to do after fill hole, coat with F/G or anything before replacing anitfoul.

If you have 22 blisters in a 10 foot radius it?s most likely due to something other than typical blisters due to osmosis. If it?s not an old repair, it probably has to do with a problem during construction that that only affected this area.