Bottom Paint

I had been a sail boater for over 30 years until I bought our Mainship 430. Sailboats generally have a barrier coat of paint under the bottom paint. I need to get 20 years of paint off the Mainship and will have it sodablasted before painting again. My question is do trawlers (specifically Mainships) have a barrier coat? My broker says they do not. Applying a barrier coat is twice as expensive as bottom paint.

John Welsh

I would not go with sandblasting but rather soda blasting. Sandblasting is much more aggressive and if the operator isn’t really good it can easily damage the hull. As to barrier coating, absolutely! Now is the time to do it if it does not have a barrier coat already. It is easy to do technically but can be hard on your back. Contact Interlux and find out how much epoxy barrier coat you need to use on your boat and then use at least that much. The number of coats is not the determining factor because my coat may be thicker or thinner than your coat, but rather the number of gallons of paint. Keep coating the hull until you use up the proper number of gallons. It is critical to recoat at the proper time or else you will have to sand in between coats. Then you apply the bottom paint at the proper time so you don’t have to sand before the bottom paint. I do my own bottom painting, it isn’t too hard except the crawling around part. Good luck.

You absolutely want barrier coat under bottom paint. There are tables that will tell you how many gallons of barrier coat to develop the proper mil thickness. The best application technique is to roll on thin coats. Alternating colors allows you to see if you missed any spots. There are 4 thin coats on my hull which gives uniform thickness and complete coverage. This is a job you will likely only do once. Worth the effort to do it well!

Ted

The Mainship factory does not put barrier coats or bottom paint on the boats that they ship to dealers. The dealer will do it, often as part of an all inclusive "commissioning" add on. Most responsible dealers will do a barrier coat, but maybe some don't.


David

Second all the above. Each paint is a little different as to cost, number of coats needed and application techniques. Yes, you want to avoid sanding between coats! I remember when I went through this process. All the info is on the web. Page 13 of the 2018 Jamestown Distributors Catalog has a list of barrier coat products and prices. Then go to the tech info on the manufacturer site to see how many coats and what the application process is. They are all different. Good luck!