What is the REAL scoop on leaving newer boats in the water?

[Ron V]

Hear a lot of talk about blistering of the gelcoat. Have they changed the resins over the years? Never even HEARD of this bull**** years ago. I know people who have left boats from the '70s in the water 5-6 months out of the year since they were new and still don't have a blister on them. Yes, the bottom gets dirty and if they were metalflake bottoms they get crazed and rough, but never seen a problem with plain gelcoat. Now everything you read does nothing but cry about blisters.

The reason I ask is I'm starting to get tired of jockeying a 19' boat around every time I want to go for a 1/2 hour blast. I'm convinced anything over 17 feet is too much of a hassle to take in and out when you use it several times a week. The village where I just bought my house has slips at the public beach for something like $350 per season for village residents and is 3 blocks from my house. Can't put a shore station in. The boat has a few small blisters, mostly on the side, that were on it when I got it. I know it was left in the water by the previous owner but it's hard to say if that caused it since it has a blister the size of a silver dollar on the dash. Almost seems like it happened when it was curing.

Any thoughts?

[10.5' Tunnel]

My dads boat is mid 80's and developed osmosis. His is in the water for 5 months. My boats always get a coat of anti-foul on the bottom. I think this is the only way to go when leaving them in the water. By the end he only loses 2 mph tops from the osmosis, and it always dries out over the winter. Osmosis is the transfer of water from an area of high concentration to an area of low concentration. Because of this I would say it is very likely that almost all gelcoated boats will develop them if left this long.

[Techno]

From what I rememer this was a problem during the 80s before and after it shouldn't be.

The cause seems to be water vapor passes through the gell and glass into a small void. There it condenses and grows.
If there isn't a void there shouldn't be a place for the water to condense. Having one on your dash kind of proves this concept.

In a way you might as well leave it in the water and let the blisters form, then grind all of them out and fill them once and for all. Apparently its going to happen no matter what you do.

[heath brinkley]

I've left boats in the water with no problem. The only boat I ever had blister was a PAINTED boat, and it blistered within a month. Imron at that, Imron's tough paint and it didn't stand a chance. I've never experienced that problem with gelcoat , maybe I was just lucky though, I'm no expert.

[David]

I think any boat will blister if left in the water long enough. How long will you keep your boat?

It has taken 10 years for small blisters to develop in my brother's boat. It is left in the water May 24-Oct 10.

Big boats that must be left in the water get an epoxy coating on the bottom.

I heard someone claim that earlier resins, gelcoats, etc were more resistent but were banned for environmental reasons. Could be true.

[transomstand]

Pretty much the standard now is to apply an epoxy barrier coat primer and then paint. All the marine paint manufacturers sell a system that would be suitable.

Pete

[Forkin' Crazy]

My mentor and trainer, who was a high performance boat builder for 20 years, says it is porocity in the gel because of lack of air pressure when it is shot in the mold. In other words, the gel didn't have enough air to break it up into small droplets.

[chris_lacey]

My V-King spends 6 month a year in the water and has since '91. I use bottom wax and have never had a problem with blisters.

[gap1949]

Re-gelcoating a 93 Ranger right now and have been doing a lot of investigating. Below water line some say to mix final coat with styrene that has wax (paraffin) in it to prevent problems.

[blkmtrfan]

gap1949 the wax in the final coat allows the gel coat to dry without a mold surface. Gel just put on a surface without a mold or milar film barrier will never dry.

The blister problem was in the later 70's to mid 80's. At the time, the major builders were getting allot of heat form the EPA and changed something in the gel process. Forkin' Crazy theory could have some merit, less air pressure would atomize less gel = less air pollution. Whatever they were doing by the late 80's earily 90's they figured how to gel and keep the EPA happy so blistering is reduced.

Also, most cruisers that stay in the water have anti fouling paint on the bottom mainly to prevent growth (weeds, barnicals, etc.) not blister prevention, but it probably dosen't hurt.

[captain fun]

I have been around boats for 40 years, the 1st time I had a fiberglass boat blister was in 1985, could be a # of reasons why this happens, but who cares, you just want to leave the boat in the water for a length of time and not worry about it, answer:
VC liquid speed, this is a teflon coating I tried that is suppose to make a boat go faster, "ha, ha" it did not go faster, BUT, no more bottom goo or gunk, anything on the bottom blew off the minute I got on plane, and no more water blisters! VC products were avail. through West Marine, but remember liquid speed, not bottom paint, VC liquid speed teflon coating!!! If you cannot find that, Boat Armor has Easy On bottom coating that is suppose to be good, but I have not tried it.......good luck, Steve

[10.5' Tunnel]

My friend tryed that stuff, liked it so much he even did the deck with it. It just doesn't shine like gel/paint, but it easy to wash:)

[bearclaw]

I worked at inland lake marinas through high school and college, and I washed more boat bottoms than I care to remember :( . Blistering from sitting in the water was definitely a problem back then, but hard to predict which boats you would see it on. My buddy's Baja did it in two weeks, but only on the sides below the waterline - not on the bottom (clear gel over flake), ditto for his dad's IMP (solid color gel).
Others could sit in all seasons, haul 'em out and scrub the algae off and they're fine. :confused:

I'd never leave anything that I cared about in the water more than overnight.

[mendo]

I can't find VC Liquid Speed at West marine. Is it called something else?

[pyro]

I used to own a 1986 Baja. Its previous owners had left it in the water, and it was messed up! It was black and red with prism pepper fleck in the clearcoat. The clearcoat below the waterline had a bumpy, hazy, light-colored texture to it. It was permantly damaged. Wiping oil such as trans fluid over it would help a little bit, but you could still see it. The same damage was evident in the splashwell, where its poor design prevented the water from draining out completely.

Seeing as many boats that had problems with under-wetted layups (not enough resin in the glass), it wouldn't surprise me if this water absorption could penetrate into the balsa core and rot the inside from the outside in some cases. Hey, it's a possibility...-

My Hydrostrteam has never been left in the water overnight, since the day it was new.

[Riverman]

I believe pyro is right WRT the cause of gel-coat blistering. Dry strands in the layup wick water into the layup through capillary action. Gelcoat is NOT impermeable to water.

I leave both boats in from May to October, the big one since 1990. The previous owner repaired some blisters (it is a Bayliner after all:rolleyes: ) painted on an epoxy barrier coat and antifouling. I redo the antifouling every other year.

I plan to paint the bottom of my little runabout next year, and I will paint the bottom of a high performance boat, (if I ever get one) as it makes fall cleanup so much easier.