Primers, undercoats and top coats

[authun]

I'm looking for some advice on finishing my build. The boat is unlikely to spend much time in the water, only a handful of times in any year and always in fresh water.

The outside has been sheathed and epoxied whilst the inside just has an epoxy coat rollered onto the ply.

I'm not looking for a showroom finish, just something that looks OK and won't flake off. The problem is of course the current epoxy coatings. Does it need a primer in this case or is it possible to go straight to an undercoat? I intend to use a decent quality marine paint, but nothing fancy like a two part. What bonds best with what in this case?

cheers
authun

[Mark Harvey]

Try asking this company they seem to know all things paint.

http://www.wilsonspaints.co.uk/

[Anders]

Remember to wash down the epoxy after it has cured for 10 - 14 days.

I would use a simple 1 comp. basecoat or primer ( 2 layers ) and a good quality household paint on top. Maybe a 1 comp. Marine paint. On the inside, I prefer a semigloss finish.

Here in Spain, they sell fishermens marine paint. Its cheap and does the thing very well. It semigloss.

[Timmo]

Paint and finish questions tend to stimulate lots of discussion and reveal conflicting views!

Provided you've scrubbed and sanded the epoxy to ensure there's a good key and no amine blush (stops paint curing and sticking) then a decent undercoat and gloss (I've used Dulux Weathershield successfully) works fine. No primer needed, the epoxy is a non porous base. Proper yacht enamel does have the advantage that it's a little more abrasion resistant than house paints tend to be. Two pot finishes are even more robust. 

You might want to check the thread on Jeremy's Aerowherry. He's experimented with plastic paint coatings that sound quite interesting and would work just as well on epoxy.

Tim.

From: "authun [via UK HBBR Forum]" <[hidden email]>

I'm not looking for a showroom finish, just something that looks OK and won't flake off. The problem is of course the current epoxy coatings. Does it need a primer in this case or is it possible to go straight to an undercoat? 

cheers
authun
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[authun]

Thanks for the replies. I couldn't see the need for a primer if it was already epoxied, it's just that I saw a West Epoxy's page where they tested different primers on epoxied ply. I know about the different household, one pot and two pot paints. From what I have read, most household paints will work but it's good to have a brand name. Household paints these days seem to come in as many varieties as marine paints.

It is a practice build and I need to practice even the painting. I'm not going to blow a lot of cash on the expensive stuff, it'll still look a bit bodged. I understand the need to clean any traces of amine blush too and key the epoxy surface. Anders' fishermen's marine paint sounds like it would be just the job if I could source some here.

cheers
authun

[Paul H (admin)]

I'm experimenting with ASDA quick dry paint on Illusion. £3 for undercoat, £4 for sheen finish topcoat. Brushes wash out in water and less pollution.

I primed the outer hull with 1 or 2 coats of epoxy, internally the ASDA undercoat primes the plywood nicely.

-Paul

[authun]

It's not a bad idea to experiment at this stage, ie. on a practice boat. The only two questions are will the paint adhere and how does it stand upto scrapes, mostly getting it on and off the trailer I imagine. Everything I have read suggests most household paints will adhere.

I have seen some forums where people have stated that it should not be left immersed in water for more than a few days, but that's not a problem in my case. I'll be happy with a few hours. It's not as if it is to spend a season on a swinging mooring subject to wind, sun and sea.

Again, from what I have read, the main selling point of the more common marine paints are statements along the lines, 'lasts upto 3 times longer'. There doesn't appear to be a super ingredient which makes it completely different. You have to go to the two packs for that.

cheers
authun