Blister basics

My apologies if all of this has been covered before, but I did search around on the site some, and just wanted to see if I understood this correctly.

Blisters are caused by water seeping--probably from the outside, but maybe influenced by how damp the inside spot it corresponds to is--into the fiberglass laminate layup layers, or however that's said. Once the water gets in there, it forms a bump. There can be a ton of these bumps, large or small, and though they might not sink your boat, they will weaken it over time, probably will grow, make it look bad, and, uh, cause other people to stare and point.

The questions I have are these: 1. Is it pretty well established that salt water creates fewer blisters than fresh water? 2. Is it pretty well established that a boat that has been blister-free in salt water for years may well blister when moved to fresh water? 3. Is it pretty well agreed that a boat that hasn't blistered within a certain number of years from its manufacture date probably won't? If so, how many years would this be? 4. I know that blister problems mostly started being noticed in the 1980s. Is there a "window" to avoid due to blistering problems--especially, of course, for Ericsons? 5. Was there a time--back in the 60's or 70's--when fiberglass boats just didn't blister? If so, does anyone know why? 6. Lastly, are there Ericson models or years or model/year combinations that are well known among cognoscenti (yourselves) as being blister-prone? How about blister-proof?

Tons 'o thanks. Sincerely.

Deadpoet

Sombody more knowledgable will straighten me out but my experience is, My 1980 30+ has no blisters but was in the Chesapeake all it's life and pulled for winters.
My 86 38-200 was sailed from CT to FL every winter and has a ton of blisters. So many that I'm taking it to Oriental and spending in excess of 10K to have it peeled and reepoxied this fall. People have told me I'm crazy and just sail it, but I think it's worthwhile and should keep it sailing till my grandchildren can enjoy their inheratance.
I think if you're looking at an Ericson it's clearly old enough if it were going to have a problem it would have shown up by now.
If you're looking at a 27 for 10K just enjoy it and pull it in winter, if it's a 380 for 150K it's a barganing chip.

I don't think there are any definite answers on blisters. General agreement is that they start to occur early, 4-5 years. If they are small gelcoat blisters, don't worry. No boat is guaranteed to stay free etc. A couple of good articles to check out:

http://www.hartoftmarinesurvey.com/guide.html

http://www.sealakeyachts.com/service/blisters.html

There is a ton of stuff out there. It is enough to leave your head spinning. I did do a gelcoat blister repair this past haul-out by grinding and filling with thickened West epoxy and the Interlux Interprotect barrier coat. Did it all myself. Lot's of time. Probably would do it again, but certainly have had my moments where I've wondered if it was worth it.

Ah yes, blisters. The hull of our 1989 E38-200 developed thousands of tiny blisters between the layup and gelcoat the year we bought in 1994. Had the hull peeled - twice - and the blisters still came back.


1. Is it pretty well established that salt water creates fewer blisters than fresh water?
Yes

2. Is it pretty well established that a boat that has been blister-free in salt water for years may well blister when moved to fresh water?
Yes

3. Is it pretty well agreed that a boat that hasn't blistered within a certain number of years from its manufacture date probably won't? If so, how many years would this be?

This is also believed to be true. But my own experience suggests that it takes at least five years to be sure. But a 20 years old boat that is blister free will likely remain so.

4. I know that blister problems mostly started being noticed in the 1980s. Is there a "window" to avoid due to blistering problems--especially, of course, for Ericsons?

Lots of Ericsons made in the late 80's were very blister prone, including both of the hulls for which we paid to have surveys. Should be some references on this site to hulls make at that time in Mexico, that are supposedly much more blister prone. I would buy an '89 again, but only with a very careful survey.

5. Was there a time--back in the 60's or 70's--when fiberglass boats just didn't blister? If so, does anyone know why?

The first boats had hulls and getcoats that were so thick they apparently resisted blistering, though I haven't ever read a definitive reason why.

Hold up a minute. Steve, you had yours redone twice and they still came back? Certainly makes me think about my plan. From what I understand it's supposed to set and dry for a month after peeling then get the epoxy. Did they do that to yours? Or what was their explaination?

Trucker Doug said:

Hold up a minute. Steve, you had yours redone twice and they still came back? Certainly makes me think about my plan. From what I understand it's supposed to set and dry for a month after peeling then get the epoxy. Did they do that to yours? Or what was their explaination?

Click to expand...

I never did get an explaination. Bought the boat spring '94, and found the blisters at haul out that fall. Small ones to be sure, just between the gel coat and the layup, with nothing structural - but thousands of them. In April '95 we launched the boat to take it down the river to the one yard in the area with a gel coat peeler. They peeled the boat, let it dry, and then coated with West System epoxy, delivering the boat to us by mid June - which would seem to have left enough time to dry out.

That fall the blisters were all back. As before they were just between the layup and the coating (this time epoxy). Thinking that maybe they botched the prep (not dry enough? not enough tooth?), they peeled it again, and let it dry all winter. Recoated that spring, and relaunched. That fall, and EVERY fall after that we would find more blisters at haul out, but not all over the hull as before. After two complete hull peels their approach was to spot grind the few that kept appearing.

I might assume that they didn't know what they were doing (and maybe they didn't). But Guegoun Brothers (sp?) is just a mile from this yard, and all the workers had been trained by them in applying the West System. We even had the folks from Guegoun stop by to look at the hull and give us their advice, but they too were stumped. If I were interested they suggested we harvest a hull plug for destructive analysis of the layup to see what the problem was, but I wasn't that interested.

This same yard had done dozens of blister peels and repairs, with our Ericson being their only failure. To their credit they never charged me for any of the re-work. But with the blisters still there in the fall of 2004 it cost me another $5000 off the price of the boat when I sold it.

Thanks.

Steve,

Hope I did this right. I was trying to send you a private thanks for your point-by-point answers. Very helpful. I appreciate it.

Regards,

John Rogers

u079721 said:

Ah yes, blisters. The hull of our 1989 E38-200 developed thousands of tiny blisters between the layup and gelcoat the year we bought in 1994. Had the hull peeled - twice - and the blisters still came back.


1. Is it pretty well established that salt water creates fewer blisters than fresh water?
Yes

2. Is it pretty well established that a boat that has been blister-free in salt water for years may well blister when moved to fresh water?
Yes

3. Is it pretty well agreed that a boat that hasn't blistered within a certain number of years from its manufacture date probably won't? If so, how many years would this be?

This is also believed to be true. But my own experience suggests that it takes at least five years to be sure. But a 20 years old boat that is blister free will likely remain so.

4. I know that blister problems mostly started being noticed in the 1980s. Is there a "window" to avoid due to blistering problems--especially, of course, for Ericsons?

Lots of Ericsons made in the late 80's were very blister prone, including both of the hulls for which we paid to have surveys. Should be some references on this site to hulls make at that time in Mexico, that are supposedly much more blister prone. I would buy an '89 again, but only with a very careful survey.

5. Was there a time--back in the 60's or 70's--when fiberglass boats just didn't blister? If so, does anyone know why?

The first boats had hulls and getcoats that were so thick they apparently resisted blistering, though I haven't ever read a definitive reason why.

Click to expand...

Steve, All your money and effort was for nill? I'm going to guess you wouldn't try to correct it if you next boat had the same issue. The one thing beside time that I can't afford to waste is money. I've put a ton of both into this boat and want it to be right before I sail off into the sunset (well, retire and spend a year in the caribbian) and that is the last big money issue I have to deal with, or NOT? I do have to move the waterline up 3" anyway we've so many add ons for this trip. You've been there done that and your opinion has alot of value.

Trucker Doug said:

Steve, All your money and effort was for nill? I'm going to guess you wouldn't try to correct it if you next boat had the same issue. The one thing beside time that I can't afford to waste is money. I've put a ton of both into this boat and want it to be right before I sail off into the sunset (well, retire and spend a year in the caribbian) and that is the last big money issue I have to deal with, or NOT? I do have to move the waterline up 3" anyway we've so many add ons for this trip. You've been there done that and your opinion has alot of value.

Click to expand...

No, if I had it to do over again I probably wouldn't have even started with the whole process. But then again, my blisters were the type that were essentially cosmetic, and never threatened the structural integrity of the layup. And since I didn't race I wouldn't care about the smoothness of the hull.

But with a new (to me) boat at the time I wanted it "perfect", so we went the whole way in trying to fix things. And in the end I guess I didn't really mind the first $6000 for the repair - it was losing another $5000 at the sale that hurt.

u079721 said:

But a 20 years old boat that is blister free will likely remain so.

Click to expand...

I just wanted to emphasise that word. If a past surveyor on my boat is to be believed, the hull developed some pretty severe blistering between age 21 and 25.

I had the same peeling process you described, and about six weeks of drying (San Deigo was the perfect place for it), before an epoxy bottom. Perfect condition ever since - over ten years now. The owner of the company that did the work gave a five year guarantee, on the grounds that if they had not laid it up properly, it would have become evident by then.

Sounds like you have had a rough one to deal with.

Gareth
Freyja E35 #241 1972