Bottom paint & warm freshwater

[Mark Melchior]

I have a year-old Catalina 250 that I keep on its trailer at the marina. The hull has gelcoat that looks like a mirror and I hate to bottom paint it, but my wife thinks she might enjoy the boat more if we wetslipped it. Our Texas lake is freshwater. Temps range from the high 50s during the late winter to almost 90 during the late summer. I've been told that warm water speeds the development of blisters.I'm thinking of using VC-17. Even if I allow the marina to do the work, I want to know the best method to prep & apply the bottom paint.What prep work needs to be done below the waterline? I know about acetone to remove the mold release wax. What else? Would a barrier coat void the Catalina warranty? David Graas at Catalina tells me that after the gelcoat is sprayed in the hull mold, a vinylester resin/chopped glass layer is applied as a barrier coat before the remaining fiberglass laminations. Is the "barrier coat" he refers to sufficient to prevent blisters?My boat is the water-ballast model and the centerboard trunk will need special attention.Your thoughts on VC17 in warm water or other recommendations would be greatly appreciated. I will occasionally pull the boat out of the water on my trailer for maintenance. I want a bottom paint that can take this type of "abuse".

 

[LaDonna Bubak - Planet Catalina]

I've heard that too

Hi Mark-I sail on the Columbia River which is pretty cold but I've heard that fresh water tends to speed up blisters so I'm guessing that WARM fresh water could speed it up even faster.The "barrier coat" David is talking about is for the fiberglass, not the gelcoat. I would call him again about the warranty issue (and get it in writing if necessary) and an exterior barrier coat. It would definitely help in preventing gelcoat blisters (which are generally what you have when you get blisters although not always). I had hundreds of them when I hauled out last year. Fixed every last one

 

[Chuck Minges]

Bottom Paint, etc.

Hi Mark,I bought a 1984 Catalina fixed keel from the original owner about five years ago. The best I can figue out, it had an ablative paint put on when it was new. I know that it had not been taken out of the water for at least 12 years until 2 months ago when I stopped procratinating. Much of the antifouling paint was still there, and the green moss would slide off easily when I would dive under the boat with a soft brush. I was amazed that the bottom was in such great shape. Yes, I probaby dough out a couple hundred blister. and faired with epoxy, but structure-wise the boat was in fine shape--no cracks in the gel coat or fiberglass, etc.

 

[Chuck Minges]

PS Bottom paint

Hi Mark again,Somehow the first email got sent before I finisned. So, I just got finished puting four coats of Pettit ACP 50 on my boat, and by the way, Practical Sailor magizine rated it best.As for blister, my understanding is that they are mayby caused by the humidity conditions in the boat factory as much as any thing else. Practial Sailor did a long article on the subject years ago. I'm no expert, but my understanding is that the problem comes from the inside not the outside.By the way, I live in Columbia, SC, and keep my boat in a slip on Lake Murray, a fresh water lake with similar temps. that you mentioned.Don't worry too much about the blisters --I've never seen a fiberglass boat the didn't have them.Hope this is some help. Get a West Marine Catalouge, or check into their Web Site--They have great explations and advice on just about all topics.Chuck Minges