Barrier coat or Epoxy for coating bare wood hull

[tomtriad]

If you saturate with Petit clear sealer you will need to overcoat with a non epoxy paint; an oil base or urethane paint or a traditional varnish would work. You will have to keep after it as it wears.

[ajay73]

Tomtriad, according to Pettit any of their paints or varnishes will work over the sealer. I don't mean bottom paints, of course. I don't want to use varnishes. I want a painted surface. I just have never run across anyone who has used a "sealer" to keep moisture out of wood. But then I've not been in the realm of wooden boats to know. I did build a 15 foot stitch and glue day sailor with plywood, fiberglass and epoxy but that is where I got sensitized to epoxy. Epoxy is the right solution but I'm just looking at alternatives given the boat won't be in the water on a permanent basis. I wonder if you could varnish and then put a paint over the varnish below the waterline. Just thinking that maybe varnish is a better "sealer" from water intrusion. Then use this EZ Sealer above the waterline with paint.

[tomtriad]

I've used the Petit sealer on bare wood cabin sides as a base under varnish. You can apply coat after coat to get a good build as it drys quickly, then topcoat with 2 or 3 varnish layers, allowing them to dry and scratching them up between coats (overnight). I have never used the clearcoat under the waterline.

Now that I have a cold molded wood epoxy boat I always clear coat any bare wood (the tiller and all interior surfaces) with epoxy before varnishing. I would not put anything under the epoxy. The entire exterior of the boat is covered in light 'glass in epoxy. I use Awlgrip 545 primer and Imron LPU (truck paint) sprayed on the topsides (nasty stuff but wears like iron). All fasteners are potted in epoxy. Boat is 38 years young and going strong.

[tomtriad]

I must defer to those who have successfully tried your proposed method. Offhand, I dont see why you couldn't 'glass the bare wood with vinylesther resin then paint over it.

The best resource would be to talk to the technical department at the coating manufacturer to make sure you are using compatible materials.

Do you know the FB group Duckworks? They are small boat building affecionados with tons of hands on building experience.

[ajay73]

As I noted before I talked with LBI Fiberglass and they said no problem glassing and vinyl ester over plywood then paint. That will be what I go with if I don't get a solid feel about sealer and paint. I'll call Pettit and ask about the sealer. Actually I could live with a sealer and varnished bottom and paint above the waterline and sealer/paint inside. That would look ok to me.

[tomtriad]

I just looked at the specs on your meranti hydrotek BS1088 plywood. It looks like it has very good characteristics, and the finish surface is blemish free. If I were building a nice little boat that lives on land, I would be tempted to finish it bright. Meranti is a very pretty wood (I have some trim pieces in high wear areas) that wears like iron - more durable than teak.

Have you considered Awlwood coatings? Very durable and designed for bare wood. They have two colored primers if you don't want the wood grain to show. A friend of mine uses the clear topcoat on his carbon fiber spars.

https://www.jamestowndistributors.co...t-detail/97753

[ajay73]

Have decided what to do. In talking to Pettit and other coating suppliers I never got a definite feel as to what to do. So, got the idea to call a small boat builder and find what they would recommend. Luckily I hit the right builder on the first call. Cottrell Boatbuilding in Searsport Maine. They are building all small boats. I explained my situation and asked if just a primer paint like Pettit EZ Prime and then EZ Poxy or should I go varnish. Just so happened they build a little 10 foot rowing dinghy that is put together kind of like mine will be (frameless) and they do the primer and polyurethane paint on all their boats. No epoxy just primer and paint. Of course, the boats don't stay in the water, like mine won't. Their boats last decades. It's a family business and talked to a lady that was more than willing to share their knowledge and knew where I was coming from. They were so forthcoming and didn't want to hide their methods. Almost made me want to buy a boat from them. So that's it. Primer and paint and no worries. Obviously the simplest way to get the job done.