SailNet Community - DIY Barrier Coat

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DIY Barrier Coat

I am thinking about doing an epoxy barrier coat on an 1986 Tashiba 40 as a preventative measure before taking her to warm tropical waters. Can anyone point me to informative websites about the process (something like a "how to")? What is the best way to remove years of old bottom paint: soda blast, scraper, sanding, chemicals? Once the bottom paint is removed, is the gelcoat removed to the laminate? Or will a sanding of the gelcoat provide enough adhesion for the epoxy to bond? What type of epoxy is used: will thickened West epoxy work, or are their special epoxy barrier coat products? How is it applied? Will the epoxy self-level or will fairing be required? I'm a fairly handy DIY-er, but is this a job thats better left to a professional?

interlux 2000E was what we used on my boat. The largest part of the job is removing the old bottom paint. I had it taken off with 50 grit. big job too! the bond is amazing! I'm just having problems with the new bottom paint sticking, my fault because we didn't sand the barrier coat. Any blisters, or fairing you should do before the barrier coat. it's rolled on, 5 coats is best. it sets up way faster then the instructions say it will. use small batches. We did under the stand locations with 5 coats first. the did the rest of the hull. It's all pretty easy tech wise. just long hours of sanding. good luck!

The spring after we purchased our boat, there was a lot of paint build up and was flaking off, etc. So I had the bottom blasted only to find these...:eek: Mostly little blisters, not deep, with the exception of about 10 that I ground out.

http://i280.photobucket.com/albums/k...7-mar06004.jpg

Here I am sanding ALL the remaining bottom paint off...wear proper safety protection!!! ;)

http://i280.photobucket.com/albums/k...tomPics002.jpg

Still going...all day long...:(

http://i280.photobucket.com/albums/k...tomPics003.jpg

After sanding down to white gelcoat, I washed it about once a week for about 4 weeks to remove bad stuff, acids, reisdues, etc. then let it dry for another 6 weeks or so :D

Then I started to fill and fair the bottom. I used West System with filler which has the brown color you see below. I also tried a vinylester product (forgetting the name at the moment) which you see in blue.

Remember...epoxy over the vinylester okay, but not the other way around ;)

http://i280.photobucket.com/albums/k...tomPics020.jpg

http://i280.photobucket.com/albums/k...tomPics009.jpg

more filling & fairing...:eek:

http://i280.photobucket.com/albums/k...tomPics008.jpg

Finally...the barrier coat application (gray)...starting to see progress, I put 5 coats on the hull with 3 more or 8 total on the bottom and forward part of the keel & rudder...:cool:

http://i280.photobucket.com/albums/k...tomPics024.jpg

http://i280.photobucket.com/albums/k...tomPics025.jpg

Before the last coat of barrier coat cured, about 3 hours in 90 degree Maryland weather, I applied the first coat of bottom paint. Doing this should help form a good bond between the two. I used an ablative paint in black, of which I applied two coats.

http://i280.photobucket.com/albums/k...tomPics027.jpg

Here I start to apply the third bottom paint coat, but in blue, so I can see when its time to re-coat...;)

http://i280.photobucket.com/albums/k...tomPics028.jpg

http://i280.photobucket.com/albums/k...tomPics030.jpg

Finally done painting...yea right...:D

http://i280.photobucket.com/albums/k...tomPics036.jpg

Here you can see where I removed the PO's try at a boot strip, I just took the bottom paint up another 1 1/2"...

http://i280.photobucket.com/albums/k...tomPics034.jpg

Finally this spring I painted a new boot stripe...:D I need to do some repairs to the stripe due to the sling when we splashed her but I'm pretty happy overall.

Its been three years now since I have barrier coated the bottom, leaving the boat in year round. This spring there were no signs of blistering. :cool: ;) :D

http://i280.photobucket.com/albums/k...stonhard02.jpg

Total cost to blast, sand (ended up renting a sander from the yard), fillers, barrier coat and three coats of paint, if I remember correctly was just over $2000.00 and about 60 hours of time give or take.

Good luck, theres lot here that you can search for on the topic...;)

http://i280.photobucket.com/albums/k...stonhard04.jpg
__________________

BTW, I used Pettit Protect
http://images.westmarine.com/full/1938612.jpg

Here's the link to International Paint's (Interlux) pdf on barrier coat application. I think it's the most used and respected barrier coat available.
http://www.yachtpaint.com/usa/hotlin...t_bulletin.pdf
Brian

Thanks guys- Great info!

T37Chef- Was it worth having the soda blasting done since you still needed to sand anyway?

Yes!!!!!! It pops most of the blisters for ya ;)

for some reason I never took pics of mine with the barrier coat on but I have them of her with a bare (blush) bottom http://i230.photobucket.com/albums/e...IMG_0154-1.jpg
http://i230.photobucket.com/albums/e...0/IMG_0161.jpg

T37Chef- I don't think I have any blisters. I thought it would be a good idea to barrier coat because its a boat that has spent its life in New England and I plan on taking it to the Caribbean. Better safe than sorry.
Why did you choose Pettit over Interlux?

I should also mention that there was a lot of paint build up. And I didn't think I had any blisters either ;) LOL. I only choose Pettit because the marina recommended it, I would imagine they are about the same?

I think your right to do the barrier coat, certainly isn't going to hurt :)

First, getting the paint off... If you have the budget for sodablasting the boat, I'd highly recommend going that route. Not only can it remove all the old paint, it will leave the gelcoat fairly well prepared for barrier coating, with only the need for a good washing. There is no need to sand down to the fiberglass. You can use Interprotect 2000E, which is an excellent product and easier to apply and use than some of the regular epoxies are. I wrote a post about applying it, and am posting again here.

Quote:

Alternating the colors helps a lot with determining where you've painted, but it is also very useful for helping you coat the areas around the boat stands. For instance:

The first layer is gray, since the gelcoat is white, and you can paint right up to the boat stand pads. Then you paint a layer of white, and leave about a two-inch margin of gray paint around the pads... then paint a layer a gray and leave a four-inch margin around the pads or about two-inches of white and two inches of gray showing...and then finish with a layer of white—with a six-inch margin around the pads—with two inches of gray, two inches of white and two inches of gray.

Then when you move the boat stands, you can fill in the pads and layer the paint accordingly... adding gray to cover the white square left by the pad.. then white to cover the gray square, and so on.

Also, by alternating colors, you can see if someone has sanded through the barrier coat when you're prepping the boat for re-painting. If there's an area that is gray or grayish, they've sanded through at least the outermost layer of barrier coat. If you had all white, you wouldn't be able to tell if they had sanded down through the barrier coat as easily—if you had all gray, you could tell they sanded through the barrier coat...but not if they've sanded into it...

I hope this helps clear things up a bit.

This isn't a very difficult job and any competent sailor should be able to do it. Having a helper is very useful, especially if you're working in warmer temperatures, as the working life of the IP2000E is temperature dependent.

Quote:

Originally Posted by mrybas (Post 544346)