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Waterproof Paint?

Posted: Sat Apr 15, 2017 2:12 pm
by island time
Ok guys I'm repairing a couple of dings in the bottom of the 23 Commander and getting ready to paint the whole exterior. I've been researching paints to refinish the entire boat and I think Awlgrip looks like a good choice but I found out that it is not made for use below the waterline. I contacted Awlgrip and inquired about this and was told by the sales department that it is indeed not to be used for that purpose. Naturally I asked why and they explained that this paint although a 2-part epoxy finish is NOT waterproof. WHAT? how can this be? Anyway I can use it above the waterline on topsides and decks only so as if this project isn't complicated enough trying to match the "Commander Shark Gray" now I have to do it with 2 different products.
Anybody have such an experience? I don't want to use antifouling paint.

Craig

Re: Waterproof Paint?

Posted: Mon Apr 17, 2017 7:18 am
by Greg Wallace
In my experience the epoxy is OK for occasional / short term immersion when the boat is out of water when not in use. Longest I can recall is about 9 days in the water with no issues. I personally think it is more resistant than mfg will admit or guarantee. Technically speaking, gelcoat is not water proof either.

Re: Waterproof Paint?

Posted: Tue Jun 13, 2017 6:17 am
by island time
Hi Greg,
Thanks for your reply, sorry I didn't respond before now.
I believe you are right about manufacturers not wanting to over-rate the capability of their products. The last time I painted the bottom of the SeaSkiff I used plain old oil based porch and deck enamel and it's holding up beautifully.

Craig Wilson

Re: Waterproof Paint?

Posted: Tue Jun 13, 2017 7:56 am
by jfrprops
there is a guy that has a classic Elco in our marina ...paints the whole hull with white porch and deck paint...best paint job in the sheds and holds up fine....always amazes me....but true.

John in Va.

Re: Waterproof Paint?

Posted: Wed Jun 14, 2017 7:15 am
by mfine
The water proofing needs to start below the paint. Look at something like Interprotect 2000e as a primer/water proof barrier coat. If the boat is trailered or in a lift and will not sit in the water more than 2-3 days you can get away with a topside paint over the barrier coat. More than that and you risk bubbles but it won't hurt the boat if the layer below is sealed.

Try to match manufacturers and products that are designed to work together. Generally you can put a single part paint over a two part, but not two part over a single so choose products before you start. Also, pay attention to application difficulty and safety. Some products like Awlgrip are recommended for professionals only while others are a bit more DIY friendly. Skin and respiratory protection requirements vary greatly.

FWIW, the only non-anti fouling bottom pain I know of is Interlux VC Performance but it only comes in white and they do not recommend tinting it. If it was me, I would talk to the manufacturers and pick out the hardest, most durable two part topside paint that they say is tintable to your desired color or paint it white below the waterline/boot stripe with VC Performance.

Re: Waterproof Paint?

Posted: Wed Jun 14, 2017 7:44 pm
by island time
I did consider a barrier coat but by design this is a thick heavy product much like anti-fouling paints themselves and that would not produce the glass smooth surface I need. It was not recommended for my project due to the fact that I am attempting to reproduce the ultra smooth look of gel coat.
The product that looks the best as an undercoat for this application is Total Boat epoxy primer. I wish I could have used the barrier coat because it is substantially less expensive than the epoxy primer but if it gives the look I'm after it will be worth every dollar.

Craig Wilson

Re: Waterproof Paint?

Posted: Thu Jun 15, 2017 6:31 pm
by mfine
The glass smooth finish comes from your prep work before and between coats and your finish paint. Well done barrier coat plus 2 part finish paint gives a smoother higher gloss finish than gel coat. FWIW, Interprotect 2000e is an epoxy primer from Interlux. Total Boat is another paint brand the also makes epoxy primers along with Awlgrip, Petit, and others.