View Full Version : Finish on miranti step box

01-16-2005, 11:16 PM
I just made a boarding step box for my boat with some leftover 3/4" miranti ply that I was planning on painting when done. Turns out it came out better than I expected and thought maybe I should varnish it or something. Any suggestions out there for a LOW MAINTENANCE natural finish that's relatively easy and durable? I already epoxied the exposed edges of the plywood, so that has to be taken into account.

I'm new to finish work, so a few questions that are probably '101' to most of you: Can I varnish over a couple coats of epoxy? Should I? What can I do to make the top surface non-skid? Should I only do the outside and leave the inside untouched, or encapsulate the whole thing? This will be out in the weather ALL THE TIME, so something easy to maintain would be great (the rest of the boat will be quite enough maintenance for me).

[ 01-16-2005, 11:36 PM: Message edited by: CJ ]

Bob Smalser
01-17-2005, 08:48 AM
Good looking box.

Here's what I'd do to it:

1) Cut a centered, 1X4-inch slot in the top for one-hand lifting without bending down as far as necessary to reach the handles.

2) Cover the end grain on the sides with 1/4-inch thick strips of H. Mahog and putty or plug all of the screw and brad holes after countersinking.

3) Fill the grain with an oil-based, mahogany-color wood filler and varnish with whatever UV-resistant spar you are using.

Grain fillers are oil stains full of diatomaceous earth applied thick with the grain, allowed to set up and rubbed off with coarse cloth across the grain to make a level surface. Then each subsequent coat of varnish is sanded to again level the surface with each coat for 4-6 coats worth.

Plywood has very thin veneer on the wear surface and "low-maintencance" finishes that don't form hard films won't protect it enough.

Sprinkle some sugar or table salt on the varnished top while it's still wet...let cure....and hose the salt off for a nonskid finish.

[ 01-17-2005, 12:12 PM: Message edited by: Bob Smalser ]

01-17-2005, 10:49 AM
Yes, you can varnish over epoxy with very attractive results. Many bright finished plywood boats are finished that way. Since you're going to be standing on it a lot f you wanted a very durable finish you might even consider a layer of 4 oz fiberglass, but if you go any epoxy route you may end up with a very slippery step when its wet.

Keith Wilson
01-17-2005, 12:28 PM
"Low maintenance" and "natural finish" are, unfortunately, mutually exclusive. A long-lasting clear finish that looks as good as varnish is the Holy Grail of varnish manufacturers, and they haven't found it yet. The problem, as I understand it, is UV light. Pigments in paint are excellent UV absorbers; a really good clear UV absorber is almost a contradiction in terms. Even if the clear film itself stays intact, the UV will break down the top few molecules of the wood and the varnish will lift. Epoxy also breaks down under UV radiation.

That said, the longest lasting clear finish Iíve found is four of five coats of Cetol over CPES. CPES cures very slowly, and seems to glue the bottom of the varnish layer to the wood. Cetol, or one of its knock-offs, is sort of semi-transparent, in between varnish and paint with LOTS of UV absorbers, which give it a muddy brown appearance. I prefer West Marineís house brand, which is a nicer color than Cetol, not so orange, and goes well on Meranti ply. Itís not as pretty as varnish; not as shiny and not as clear, but it lasts almost as well a cheap white latex house paint.

01-17-2005, 02:33 PM
The wood and epoxy needs to be protected from UV and water. A minimum of seven coats of clear fininsh (aka varnish) will be required as UV protection. Nicks and scraps will have to be repaired in a timely manner to retain protection. 1-3 fresh coats of varnish will be required each year to keep the finish effective.

If you're willing to put in this kind of effort you'll have a beautiful entry-way for your vessel. If not there's nothing wrong with a good lasting paint job.

Try 3M's non-skid clear or white tape on the step for traction. Durable, easy to clean and simple to replace when needed.