Hull Blisters under trailer bunks

[gwozhog]

Compete and total bull$hit!!

It is not common for boat gel coat to blister!! Moreover, even more bull$hit for it to happen because of dry bunks. Who at MC came of with that crap? It's damn near the dumbest thing I've heard on these forums and some one at MC corporate office should put a stop to that crap.

Own it!!

How many hundreds of thousands or even millions of gelcoat fiberglass boats out there that never blister? Common? You mean rarely does it happen and more then likely it's catalyst issue if anything.

Want to destroy brand loyalty? This is how you start it.

If its not common how come my last 2 Mastercrafts have had blisters on the hull where it rests on the bunks? I think it has something to do with the way the boat is used. I trailer to and from my river over a 100 times a year. I also ride year round so my bunks are never completely dry.

[WhiskeyTango]

Blisters occur from extended water contact, in this case probably from wet bunks. The polyester gelcoat is inherently porous and eventually water gets through where it reacts with the laminate layers, pulling in more water by osmosis and eventually reducing the strength of the laminate. But that takes a long time.

I read somewhere that it happens faster on thinner gelcoat, but don’t know that for sure.

To the OP… My 2 cents would be that you check it annually and if the blisters appear to be getting worse, have it repaired.

I’d bet many of us have blisters above the bunks…

If you have it repaired, a vinyl ester primer barrier coat under the gelcoat may help prevent recurrence.

By the way, repair is a BIG job. Done right, it requires removal of the gelcoat in those areas and possibly some work on the fiberglass laminate.

[CantRepeat]

If its not common how come my last 2 Mastercrafts have had blisters on the hull where it rests on the bunks? I think it has something to do with the way the boat is used. I trailer to and from my river over a 100 times a year. I also ride year round so my bunks are never completely dry.

Out of 100k boats your two are antidotical at best. You could say, it's common for you but not the lot.

[waterlogged882]

Compete and total bull$hit!!

It is not common for boat gel coat to blister!! Moreover, even more bull$hit for it to happen because of dry bunks. Who at MC came of with that crap? It's damn near the dumbest thing I've heard on these forums and some one at MC corporate office should put a stop to that crap.

Own it!!

Agree.

[gwozhog]

Out of 100k boats your two are antidotical at best. You could say, it's common for you but not the lot.

I would bet many boat owners have them but have never lifted their boats off the trailer on land so they are not aware of them. My current boat I felt them for the first time when I had a ski rope stuck on a skeg and I dove under the boat to free it up. Also if a boat has sat in hot storage unit for a few weeks the gellcoat blisters disappear until you get the boat wet again. So they could very well go unnoticed for most owners

[bturner2]

If we're going to go back to "it's the carpet" again and the carpet is causing a $200K boat to blister after only 2 years (which BTW I don't buy for a second) due to no fault of the manufacture's layup or materials then it would seem obvious to me that the trailer manufactures need to start using a different bunk material or method to support the boat (anyone remember EZ-Loader trailers with their roller setup?). The idea that someone can drop that kind of cash and there be no recourse when their Gel Coat starts to de-laminate (because that's actually what's occurring when a blister forms) after only 2 or 3 years even when the manufacture states a lifetime warranty on the hull seems ridiculous to me. Based on some of the hull warranties stories I've heard over the years there's really much they actually cover. If this was the response I got I'd fix the boat and buy another brand on principle alone.

As to just not seeing the blisters.... For years I had my boat on Shorestations with carpeted bunks and trailers with carpeted bunks. Since the bunks were in different locations between the Shorestation and the trailer I would have seen blisters either while on the lift or when I did the annual bottom waxing but never did. Based on what the OP is being told I'm a very lucky guy since this is apparently so common.

[JohnE]

Here is an old thread with a lot of good info. https://teamtalk.mastercraft.com/for...=20133&page=11

It's not "the carpet", it's "the water".

It does seem fairly rare from all that I've read here over the years. But it doesn't seem surprising. If it happened to me, I'd be pretty upset. But I would say I would have had fair warning.

[TolCarMan]

This might be a dumb question, but why do you care? The blisters are likely out of sight 99% of the time and they aren't affecting performance. I've never noticed them on any of my boats (I exclusively trailer), and even if I did I'm not sure it would be worth the coin to get them fixed knowing they could come back. I'd try to forget about them and go have some fun.

*I realize I'm probably in the minority lol

[CruisinGA]

I noticed hull blisters on my 2001 X9 from carpeted lift bunks. I removed the carpet and installed plastic bunk covers and the blisters seem to have gone away.
Based on responses to me when I discovered this issue years ago, and the other comments in this thread, this condition does seem reasonably common, it does seem to be a cosmetic issue and I'm not convinced it matters.