Thread: Painting my plywood boat.....

Painting wood boils down to a couple of issues. Is the wood stable or not.

Stable wood is epoxy encapsulated, though there are other ways, this is the primary method in marine applications. Stabilized wood can be treated as if it's plastic or metal and fancy two, three and four part paints can be used.

Unstabilized wood, needs to be sealed (not the same as encapsulation), though preservatives are a whole different can of worms. I personally don't use them any more, preferring to use rot resistant species or epoxy (or both). Unstable woods will move with environmental changes, so the fancy, really hard paints will not stay stuck.

This leaves you with the single part polyurethanes, modified alkyds, straight alkyds and acrylics as the choices on unstable woods.

Plywood is a different animal. It's much more stable then solid wood. In fact it's treated as a "wood product" not real wood. This is similar to cheese spread being a food, not actually a cheese, but a cheese like product.

Plywood doesn't move nearly as much as solid woods, so it's dimensionally stable. It does change moisture content though, which can affect the grip a paint has on it's surface. So, in this regard, it's best to avoid the fancy paints and stick with the list I mentioned above.

On the other hand, if the solid wood or plywood surface is encapsulated in epoxy (properly) you can paint it with anything you want. I have a 4 part, solvent based paint system in the shop now that costs about $400 a gallon. It's shinnier then fresh drooled on a baby's cheek, hard as guessing the winning lottery numbers and durable as your in-law's appreciation of your addition to their family.

There's quite a bit about paint on line and in books. Most of it is out of date and doesn't address some of the latest offerings from the paint manufactures. As a rule, use the single part paints unless you have encapsulated the part(s). Naturally, encapsulation is another subject entirely.

A gold star to PAR for services to literary imagery.

MIK

Very well put Par!!!

We usually recommend epoxy over ply then a 2-pack epoxy high build undercoat over that. This goes quite hard over a few day so is best sanded next day. We also have a pigment to put in the high build so you can tint different coats to see how far you sane.
Finally a range of top coats, mostly polyurethanes, depending on application method.

Whatever you do remember surface prep is 90% of having a lovely finish!!!

Mez

If using a single pot paint over epoxy an undercoat is important.

Sometimes a single pot topcoat will not dry properly put straight over epoxy - only about one in twenty - but it is pretty tough to be the one that gets the prob.

Best to use an undercoat first if going this route.

Best wishes
Michael