** Barrier Coat ? **

scottsnyder

Cadet
Joined
May 3, 2005
Messages
17
I recently purchased a 1993 25 ft center console, that has always been kept dry on a trailer. I am going to be keeping the boat in the water, all spring, summer & fall in Annapolis MD. The boat has never had any bottom paint of any kind on it before. My question is this - Should I epoxy barrier coat the bottom before the bottom paint, and if so, how many coats are required?? Two people I talked to said that a minimum of 3 coats of barrier coat, and 2 coats of bottom paint - another person said one of each, and another person said skip the barrier coat, and just put on bottom paint... And, are there any brands that you recommend?? Thanks - this forum is awesome, and I am learning tons!!!
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,089
Re: ** Barrier Coat ? **

New.. The instructions on the barrier coating will assist you in determining how many coats are needed. Not all barrier coat brands require the same number. Also, since the barrier coats are epoxy-based, the dry time between coats is temperature-dependent. That is, the dry time between coats specifies a minimum and max time prior to recoat, depending on the average temperature. On my 19' bowrider, I used four coats of barrier coat and three of ablative bottom paint. Some barrier coat brands want you to use 6 or more coats to achieve a certain thickness.
 

scottsnyder

Cadet
Joined
May 3, 2005
Messages
17
Re: ** Barrier Coat ? **

Chris: Thanks for the info... I didnt know that the number of coats was brand dependent. My other question is: is a barrier coat even necessary?? I have heard different opinions.. I am assuming that it cant hurt, but is it really necessary on a 1993 hull that has never had any paint on it to begin with??
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,089
Re: ** Barrier Coat ? **

That is a very good question. A barrier coat is only necessary if the fiberglass will absorb water, and then blister. You may ask the manufacturer what kind of resin they used (polyester, vinlyester..) to lay up the hull. It is possible they used something that would not require a barrier coat.<br />If you do not need a barrier coat, you should still use a primer, prior to applying the bottom paint. There are many brands, and your bottom paint will stick much better to a primed hull. We have all seen those hulls with the big chips of bottom paint missing. It is likely those hulls were not primed.
 
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