Bottom paint, petit horizon right on gelcoat?

[tribologist]

My understanding is that the A25 is not known to get blisters and we are not keeping it in the water. Im thinking of sanding it down to the gelcoat and then roll two layers of pretty blue petit horizons.

1 gallon should be ok for two coats? Right? (500 ft2/gal)

[nebulatech]

Tribologist, I can't speak to coverage from experience, but that seems close. Regarding application to the hull, page two of the product data sheet is instructive:
http://www.pettitpaint.com/media/4014/p ... pds-17.pdf

I'm very surprised to see them calling for 80 grit sandpaper. I used to own a small coatings distribution which sold to mostly cabinet and furniture makers. Our recommended grits were 120 for bare wood and 220-320 between coats. For painting boats and cars, its much finer, 400-800 grit. Sanding anything with 80 grit ought to provide plenty of rough surface to form a strong mechanical bond. Regarding the designer hull prep solvents Petit recommends, I would feel comfortable replacing them all with acetone. It won't harm the fiberglass, but it's aggressive enough for removing most contaminants.

Out of curiosity, why are you wanting to sand it to bare glass/gelcoat?

[WillieC]

Correct on the lack of blisters.

If you are going to this much trouble, all the way to gelcoat, think about putting on at least a couple coats of two-part barrier paint. Pettit instructions recommend this.

I highly suggest following their instructions to a tee.

We also bought a gallon of their bio-blue hull cleaner for removing any residual wax. I was glad we did that because, as daunting as the job looked when I finally got the boat off the trailer, whatever bottom paint was on there started peeling off in big chunks. I was able to use a 2" carbide paint scraper for removing almost all fifty coats of bottom paint. It appeared that nobody bothered to remove the original gelcoat wax before the very first coat of bottom paint.

No getting around it, it was tedious. I really was glad the paint came off so easily with the scraper. I was concerned about sanding it off for fear of driving the gelcoat mold release wax into the hull. Once scraped, then Bio-blue, then sand, then Bio-blue again...two coats of two part (I used Pettit's) then bottom paint. Timing is a bit critical so following instructions will save you a lot of extra work.

We used Hydrocoat-Eco, but there is a new product that might work well too. I am a bit disappointed that the hull grows slime, we are going on year three. (Normally, I understand that two years is considered not bad for bottom paint.) New bottom paint just arrived today but this time, with all the proper prior prep, other than getting the boat off the trailer, it will be a breeze.

One gallon of Bio-Blue goes a long way. Share with a buddy.
One gallon kit each of two-part barrier coat, gray and white. Plan how much to mix, you won't use it all. Have other projects ready to use up what you over-mix.
One gallon of bottom paint will give you almost three coats on the A25.

I am not now, nor have ever been a member of the Pettit Paint Party.

[DesertAlbin736]

Been there done that, just like WillieC (past posts have shown pictures, but I'm not at the desktop PC to upload again). Triboligist, as you know my hull # is literally one number behind Driftless. In 2016 I sanded through 4 layers of old bottom paint down to gelcoat, did the Bio Blue treatment thing & painted with Pettit Hydrocoat ECO. Saw absolutely no sign of blistering. In fact everything I've read about A25s is that they generally don't have a reputation of blister problems. I didn't do a barrier coat, but my boat stays on the trailer full time & the longest time it's in water is a max of 7 weeks once a year & otherwise only 2 or 3 nights at a time. If I was in a position to keep La Dolce Vita full time in a marina I'd probably do a hard epoxy type paint rather than ablative.

[jerridsc]

DA. Doesn’t keeping your boat on the trailer much of the time cause the anti fouling paint to become inactive over time?

[Bob Noodat]

DA. Doesn’t keeping your boat on the trailer much of the time cause the anti fouling paint to become inactive over time?

That has been on my mind too. I found this review from 2017:
https://www.sailmagazine.com/diy/eco-fr ... ntifouling
In the article there is this quote:

Luritek Inc., on the other hand, employs what it calls “stenopropholicity,” as the basis for a multi-season hard antifouling it calls Eco-Clad Bottom Paint. Once applied, Eco-Clad slowly biodegrades to create a food source for a friendly biofilm that naturally repels any other organisms trying to hitch a free ride. Eco-Clad also employs a tough epoxy resin that makes it tough enough for true multi-season performance.

For the expense of these paints, and with a boat that is out of the water 90% of its life, I don't want to be doing this every season. I am actually wondering if there is any reason I should even apply antifouling with a boat out of the water as much as mine.

[DesertAlbin736]

jerridsc,

Yes that is the case. Picked up a lot of slime on the 2018 Desolation Sound cruise when the paint was 2 years old, but the green slime washed off fairly easy. Repainted again last year at the same time we did the deck painting project & went back to the Gulf Islands again June & July last year & didn't get slimed. Folks you do not want to know how much $$ I've put into this boat.

If we weren't doing 2 month cruises & subject to AIS inspections in transit on the road & only did occasional overnights on the lake I would leave it bare gelcoat. Fact is, having done so since 1998, just buzzing around the lake & occasional anchoring in coves, and considering in summer it's hotter than Hell, is so boring I would have given up boating long ago. Or at least stayed with sailboats, but even that is so been there, done that since I'm not interested in racing.
In fact that's probably why many of our older long time sailing club members have sold their boats & moved on to RV'ing and the club has added land based camping events in an effort to retain & attract membership. For whatever reason the younger demographic is not interested much in sailing. Likewise doubt much interest in slow trawlers.

[Bob Noodat]

In fact that's probably why many of our older long time sailing club members have sold their boats & moved on to RV'ing and the club has added land based camping events in an effort to retain & attract membership. For whatever reason the younger demographic is not interested much in sailing. Likewise doubt much interest in slow trawlers.

Not surprising that it's generational. The same is to be seen in classic car clubs, white and grey hair. It is interesting that in the UK canal boats, or as they are usually known narrow boats, have become a young family thing, having pretty much died out into the 80s. Very gratifying that people in their 20s and 30s are restoring and using these lovely old things.

However, if you are young, or any age, and live in BC, you won't feel that the Albin classics are very interesting, or at least not open to any new interest. Go to the Albineers website and there is no possibility of registration, no contact address, and quite obviously they don't want anyone new. I went to the lengths once of emailing the webmaster, but did not receive the courtesy of a reply. I guess I they're doing just fine without new members.

[nebulatech]

However, if you are young, or any age, and live in BC, you won't feel that the Albin classics are very interesting, or at least not open to any new interest. Go to the Albineers website and there is no possibility of registration, no contact address, and quite obviously they don't want anyone new. I went to the lengths once of emailing the webmaster, but did not receive the courtesy of a reply. I guess I they're doing just fine without new members.

I noticed it is near impossible to communicate via the Albineers website, but they are a friendly lot. You have to message them through the Google Groups link. Took me a while to figure that out...

[Bob Noodat]

nebulatech: I'll take your word for that. A pity the webmaster apparently did not think it worth communicating in any form. If you have a web site to encourage an interest and disseminate information about some thing, and neglect to facilitate or even respond to the sort of interest you might hope to stimulate, then it strikes me that really you are saying that only the private door is open.

Which is of course their right.