Barrier Coat Yes or No?

[lingerfeltja]

I am having the bottom blasted to remove many layers of old bottom paint. I will let the bottom dry over the winter under cover. I have read MANY forums on this question - barrier coat yes or no - with no clear decision.

If the owners of 37C s recommend a barrier coat is there any consensus on which one(s) work effectively. Thank you.
Jim

 

[wufibugs]

I am also going to soda blast the bottom of Windmistress. I decided to repaint with SCX copper pro hard. I checked with the Blue Water regarding a barrier coat. Their rep recommended 3 coats bottom protect primer, and 2 coats of SCX, with a 3rd topcoat at the water line. No barrier. Course, I am in year round salt and you are in fresh so the advice might not apply.

 

[Sanfelice]

You didn't say if you have any blisters now. Blisters, repair and prevention, is a black magic. This article may just leave you more in doubt but is an interesting read.

http://www.yachtsurvey.com/BlisterRepairFail.htm

 

[Jim Legere]

My 1983 H37C has no barrier coat and no blisters.10 years ago, when I had the bottom stripped down to the gelcoat, I debated applying a barrier coat and decided that it was not required. The boat spent the first 18 years in the northern Chesapeake and has been in Nova Scotia for the next 12 years. Colder water and spending 5 months of every year on the hard are not conditions conducive to formation of blisters on a well-built hull. If the boat was in Florida and wet year-round, I would probably go with barrier coat just for peace of mind.

 

[TLW]

If I were blasting the bottom, I would absolutely barrier coat. More importantly, if I were in Michigan in the Holland to Whitehall area (which I am,) I would be VERY, VERY CAREFUL about who was doing the blasting/barrier coat work. Message me privately, if you like.

 

[Dalliance]

These boats need a barrier coat. Even if they are out of the water half the year. InterProtect 2000 seems to be the standard around here. I put it on my '82 H30 last spring after stripping the bottom the previous fall, drying it out indoors over the winter, and repairing a few minor (1/8" to 1/4" diameter) blisters that had been hidden under layers of old bottom paint.

 

[Dalliance]

I am also going to soda blast the bottom of Windmistress. I decided to repaint with SCX copper pro hard. I checked with the Blue Water regarding a barrier coat. Their rep recommended 3 coats bottom protect primer, and 2 coats of SCX, with a 3rd topcoat at the water line. No barrier. Course, I am in year round salt and you are in fresh so the advice might not apply.

Wufibugs

Three coats of primer sounded unusual so I went to the Blue Water web site and, if I was looking at the "bottom protect primer" you refer to, it's called Bottom Protect High Build Epoxy Primer and the bullet points include:
- "seamless high build epoxy creates a[n] impermeable water barrier"
- "heavy duty 3:1 epoxy coating that prevents water absorption and blistering"
They call it primer but functionally it's a barrier coat.

Their Copper Pro SCX Hard is interesting. It's 67% copper!

 

[wufibugs]

Dal, you're right. Their primer does seem to amount to a barrier coat. I went with the SCX because it was highly rated by Practical Sailor and the high copper content. Probably the last year it will be permitted in the Bay.

 

[Leroy McMillan]

There are varying degrees of "Barrier". At the top in my opinion is the west system method of adding aluminum plates to the resin then building up layer after layer. Inter protect 2000 and the like are next, then come your standard "primers". I live in Florida so we see great benefits from a true properly applied Barrier Coats.

 

[DianaOfBurlington]

Short answer: yes.

http://dianaofburlington.blogspot.com/2013/09/waterline-stripe.html