HELP!!! Gelcoat leprosy, is my season over?

[Doug W]

I am at a loss and borderline heartbroken. My boat's bottom had wax but no other barrier coats. I trailered it the first 3 years and put it into a marina last year. It spent May thru October in the water, the longest single period in the water was about 7 weeks. The first time I pulled it out after a few weeks, it had slime below the waterline that pressure washers were hard pressed to fully remove. I scrubbed the bottom clean nearly every weekend in the water--as far as I could reach. I could feel the slime that wouldn't always remove and that could have been blisters forming but I didn't see any.

I pulled it out, pressure washed it at the end of the season and stored it in my barn. running late this year, I had a detailing service come out and clean/wax/treat/buff the hull. I was so impress with what I could see that I didn't look below the trailer.

Today, I jacked the boat off of the trailer a few inches so that I could clean and wax the points where she rests on the trailer. That's when I noticed that the hull wasn't clean underneath towards the center. THEN my heart stopped when I saw leprosy or pimples by the thousands some where it was not clean and some closer to the trailer where it had been cleaned. I Quickly cleaned off a dirty area with an Oxy hull prep and they are still there. I was hoping it was droplets of their chemicals hardened below. I'm heading out with poliprep, acetone and any other chemical I can find to see if the pimples scrub off. My fear is that I have severe blistering and I don't know what to do or where to take it for repair. I see my entire season flashing away starting with canceling our long sail vacation plans.

Here is a picture of an area I cleaned/scrubbed with the oxy cleaner and a close up.


Doug

[Russ]

Yup, you have tiny blisters. I have 'em too. I've had them for a few years and I haven't repaired them.
Don't sweat it. You can enjoy your summer. If you want to fix them, you can at your leisure. I doubt they will get worse or do any long term damage.
Pop one and see what happens. If nasty wet acid like substance oozes out, you may have some worries. I doubt it will though.

I suppose I'll eventually sand mine down and fill them and barrier coat the bottom.

--Russ

[mrron_tx]

Hi Doug : Glad to see Y'all made it through this round of Tornado's as well.... sorry to hear about he blisters .. But ... Ya gotta admit that only Russ could deliver that news in such a calm and non-alarming manner Ron.

[mastreb]

Firstly, there's nothing to worry about even if you do nothing. It's like getting your first real scar.

Also, the correct repair is to sand it rough, put two coats of epoxy barrier coat on, and then three coats of ablative bottom paint. I had a boatyard do mine when I had half-inch thick barnacles on the bottom.

Seriously, every boat on the planet is going to wind up with bottom paint at some point in its life. It's basically just a rite of passage.

Matt

[NiceAft]

If you only use the boat in fresh water, you can get away with only a barrier coat. That is what I did nine years ago, and never painted. The original barrier coat is still there, and at the end of each season I get rid of the slime with Slimmy Grimmy. I think the barrier coat was Interlux 2000 or something like that.

Ray

[Doug W]

Hi Doug : Glad to see Y'all made it through this round of Tornado's as well.... sorry to hear about he blisters .. But ... Ya gotta admit that only Russ could deliver that news in such a calm and non-alarming manner Ron.

So true! Thanks for the quick encouragement Russ,Ron,Matt & Ray! I REALLY appreciate it. I am returning to my customary humor now that the initial shock, panic and heartbreak is past. I rarely get anything brand new like my boat so I've babied her so much.

I am thoroughly scrubbing the bottom with polyOx which works really well. I have VS721 to coat and buff with this year instead of rain dance liquid wax. I was planning on that before I found the blisters. I continue to do that and will look at fixing the blisters in the fall complete with a barrier coat.

Now that my boat is a leper, I am already practicing the ancient phrase, "Leper, outcast, unclean" for anytime someone gets within 50 meters of me.

We will have it in salt water for a week next month.

Thanks again! I am canceling my slip and will keep her dry and 'trailered'.

Doug

p.s. The tornadic storms slid just miles north and south of us yesterday..We were very lucky!

[NiceAft]

Don't forget the quarantine flag

Now that my boat is a leper, I am already practicing the ancient phrase, "Leper, outcast, unclean" for anytime someone gets within 50 meters of me

.

Ray

[reastmure]

Yeah I have a few of these little pimples on my boat too - just in one location. Good to know this is not uncommon. I was mildly concerned and wondering if they might spread? My boat has never been in salt water so far as I know. Maybe they help to break the surface tension so I go a little faster?

[mastreb]

Blisters are most common on freshwater boats that have been slipped in their first few years of life. My problem wasn't blisters, it was bottom growth, which is far more common in saltwater tropics.

Atmospheric variables on the day of manufacture are partly to blame; cold humid days result in boats with more blistering problems. Slipping while the resin is still curing speeds up the process dramatically, so its actually most common on new boats.

In any case, its my opinion that all boats should have an epoxy barrier coat from the factory, but that's also best applied the more cured the FRP resin becomes, so it's arguably better to wait until the boat is two to three years anyway.

Really new boat owners just need to be appraised that they've got a $2000 finishing job coming in two years.

[Russ]

From what I've read, most reports of these occur in fresh water. That may also be because these are where most don't use bottom paint.

My first year I got them. Freaked out like you. Then found it's a common issue. My boat has not gotten any worse and I haven't fixed them. It's a lot of work to do that. Sanding, filling, coating. There's a reason I haven't put bottom paint on. It's a lot of work to prep it right, and then there is getting the boat lifted to paint the trailer spots.

My boat has been slipped for 6 years now, blisters have not gotten worse. Yea, eventually I'll paint it, but that shiny white bottom looks so nice. And it's so convenient to just hop on board with provisions and head out without rigging, launching, waiting for the ramp. Weather gets nasty, we have a home to park her to sit it out.

I used the Aurora VS721 a couple of years. I'm not sold that it does any better than plain wax. In fact, I ran out half way through last year and used regular wax for the other half and didn't see any difference in slime. This year, I may add lanolin to the bottom to see if that helps.

I have a siding brush on a stick that I wipe the bottom with from the dock. Seems to get most of the big junk off. Then if we are beached or something, I'll go over with a brush and get the slime off. Eventually, I'll get tired and just paint it. No boat yards, so it's all me to do this.

--Russ

[Doug W]

Don't forget the quarantine flag

Now that my boat is a leper, I am already practicing the ancient phrase, "Leper, outcast, unclean" for anytime someone gets within 50 meters of me

. Ray

"Leper, Outcast, UNCLEAN" he bellows from the helm...
Already installed a new block at the top of the mast. The quarantine pennant will fly there.

I must remember to anchor downwind of our community raft ups...

Thanks guys, I'm feeling much better already and Russ, you've encouraged me a lot!

Doug (Leper boat)

[Steve K]

If/when you decide to repair the bottom, take a look at these products. (under "Repair, faring and priming applications)
http://www.duratec1.com/ProductList.html#marine

Vinyl Ester primers are being used more often in blister repair. Turns out it is proving to be as good or better than Epoxy as a barrier coating.
Also, you can apply most any paint, or new Gel Coat over it.

BTW,
Although my D boat is stored on the trailer and is usually not in the water more than a couple weeks at a time (wasn't always the case), I stripped and sanded the whole bottom a few years ago and haven't gotten any new blisters. The hull is just wet sanded (forget if I stopped at #220 or #320). I intend to re-finish her one of these days. But nothing is getting any worse.
It is a little freaky though, when I check my batteries (under starboard saloon seat) and see those little specks of light shining through the hull where the, now opened, blisters are.

Really, blisters are nothing to worry about unless you are fairing out a racing hull They just look bad and look worse after you break them open....... all those little dark spots on your pretty white hull.

Hopefully I'll get time to do my hull later this year. I do plan on using the Duratec primers and finishing in nice pretty, shiny Gel Coat. No need for bottom paint on a trailer stored boat and I can easily maintain a truly fared and race ready hull I don't really race the boat much, but just like to get the best out of her......... and she looks so good on the trailer when she is all white and shiny Also, Gel Coat is so easy (for me anyway) to repair and blend so it not a problem to fix those little trailer dings, or where it wears off the bow from beaching etc.

Best Breezes,
Steve K.

[Russ]

I must remember to anchor downwind of our community raft ups...

Doug (Leper boat)

Just remember, you can't see them from above the waterline. So unless your raft ups include scuba diving, nobody will see them.

Enjoy sailing and try not to think about them. It will be your secret.

--Russ

[mrron_tx]

Well...... Now that I've heard that boats made in the winter and used in fresh water .....the only one missing is the slip. My Mac was built 1-14-2011 ( I don't think Cal has that cold of winter tho ) It has only been in the water maybe 60-70 hrs total trailer/inside stored .... And I still could not resist the temptation to slide under and have a look......All's well so far Ron.

[Russ]

Well...... Now that I've heard that boats made in the winter and used in fresh water .....the only one missing is the slip. My Mac was built 1-14-2011 ( I don't think Cal has that cold of winter tho ) It has only been in the water maybe 60-70 hrs total trailer/inside stored .... And I still could not resist the temptation to slide under and have a look......All's well so far Ron.

Salt water is more dense than fresh, so that could be one factor. Fresh water can more easily permeate the gelcoat. I haven't heard boats built in winter are more susceptible, however temps can affect gelcoat curing I suppose as would humidity. Was it raining when they molded your boat?

Also, salt water slipped boats almost always have bottom paint to prevent barnacles etc. So that would provide more of a barrier to water intrusion on the gelcoat.

The first year I slipped my boat (and got blisters) the bottom was factory bare. No wax, no barrier of any kind. Since then, I wax it. I wonder if I had a wax coating to fill gelcoat pores if it would have blistered or as bad. Too late now.

Good thing is I can't see the blisters from the cockpit.

--Russ