Need Advice on Bright finishing occume ply

[Richard Jones]

It's almost time to stain the outside of my 15' Rushton pulling boat build. I know that occume is best painted, but I prefer a bright finish. Anyone with experience at this? I've bright finished one other occume boat, but feel it could have been done better. Does this wood need a grain filler prior to stain and varnish? Any other pointers would be great. Thanks.

[eastern270]

I finished my transom bright. After I glassed the transom I laminated a quarter inch sheet of okuome over it. Sanded it with ending with 400 grit sandpaper. Stained it with minwax stain from home depot. I experimented with everything first on scrap okuome. After the stain dried I sanded again with 400 grit sandpaper just to remove the little bit of raised grain from the stain. Coated it with three coats of system three resin. Sanded again and sprayed it with eight coats of system three clear lpu paint. http://i250.photobucket.com/albums/gg280/eastern270/boattransom.jpg

[Thorne]

My understanding is that grain fillers are more for indoor furniture than outdoor boats. Can we take it that the ply is completely raw, or is it coated with epoxy in places?

My only experience with varnish over ply has been to coat it with CPES first, then hot-coat the first layer of varnish over that. Seems to have held up fine and makes a great base-layer for the varnish.

But the downside is that you get a UV-sensitive coating that must either be protected by varnish or sanded back to the wood when the varnish fails and needs revarnishing.

You'll want to experiment with various color stains, and I think that the oil-based products work better with traditional oil-based varnish. If your ply surface varies the color may also, so you'll need to test on various scraps.

[David G]

You're right that occoume is not startlingly beautiful plywood. The color is ok, but not gorgeous. Because it's typically rotary cut, the grain is not particularly lovely. I'd agree that a stain would be in order if you intend to bright finish.

To fill the grain or not is primarily and aesthetic decision. Unfilled will give a slightly more minutely-speckled look because the stain will collect in the open pores and remain darker there. It will also tend to give less of a mirror-smooth varnish finish, until/unless you've laid down a lot of varnish and sanded it back to dead flat at points along the way. I never fill unless a client wants it.

To stain, I would use an oil-based pigment stain, or one of the brands (like Old Masters) that combines pigment and dye stains. Apply and remove per instructions. Let dry thoroughly. That can be as little as overnight in hot dry conditions, or as much as 2 - 3 days. Apply two coats of thinned varnish, then a full-strength coat. It is after this first full-strength coat that I first sand. Before then requires too much care to avoid sanding thru into the stained area. Touching up such a burn thru ranges from difficult to impossible. I prefer not to take the chance. Then go ahead and apply your normal 318 to 542 coats of varnish, like normal.

Or... you can skip all that rigamarore and pick a lovely paint color ;)

[JimConlin]

I once built a mahogany pram for the deck of a Concordia yawl. The yawl's topsides were being re-varnished at the same time by the Concodia Company and we wanted to get as close a match as possible. Here's the 'system' recommended by the Concordia paint foreman at the time, as best as I recollect it.:

Sand fine, raise grain, sand again.
Apply one even thin coat of of Pettitt #2018 sealer.
thin Pettitt #1081 red mahogany and #1082 brown mahogany filler to the consistency of cream, mix them in approximately equal quantities. Apply a full coat, let soak for a while and rub off with rags across the grain.
Apply a coat of conventional varnish thinned 50%.
Sand very lightly.
Apply another coat, thinned 25%.
Apply 4 + more coats, thinned only as needed to be workable.
Go easy sanding early coats, to avoid blowing through the stain.
I can't remember what their norm was, but on my small dinghy, it was easy to get carried away.

I recollect that we used Epifanes varnish.

There are similar filler stains from Interlux and others.



Okoume has a pretty bland color, so it badly needs staining. I prefer the marine filler stains because they fill well and I have found that they keep color pretty well when exposed to sun. I'm not convinced that stains compounded for cabinet use or analine stains will do as well.
I don't use epoxy sealers over soft woods like okoume because the woods are easy to dent and when they're dented, the epoxy film will fracture, creating a much bigger repair problem. I'm also not convinced that epoxy will adhere well to oil based stains.

[AstoriaDave]

Richard,

I've used occume quite a bit for sng boats, and for various parts of a couple small boats, one a pram and one my 20-ft Bartender. I like its subtle grain patterns, and feel it is a good contrast to painted surfaces, unstained. Some have alluded to the need to test stains to make sure that resin will stick to the surface after the stain is applied. This is critical. If you check the System Three Epoxy Book, I think you will find they recommend not using oil-based stains. Others have done so with good success, but testing is mandatory.

David G warned about the paradox of a UV-sensitive layer (resin) under a protective layer (varnish), such that if/when the latter needs renewing, often some or all of the resin underment needs work, also. This depends on how hard you use the boat. Myself, I erred on the toe rails of the Bartender, failing to leave enough resin over some mahogany (not occume), and the two-part clear "varnish" over it is not enough UV protection to prevent the thinner areas from changing hue. My bad. In a couple years, I'll have to refinish them, a real PITA.

Myself, I am a low-maintenance guy, and prefer to lay some serious very protective two-part paint over the occume which will receive abuse (hitting things and/or weathering from sun and bikini-clad visitors), and bright-finish the parts not subject to wear and tear.

Take a look at the helm area here to see both kinds of treatment: http://www.pbase.com/bartenderdave/image/90184887

For contrast, to see how a huge expanse of "bright" occume might look, this may help: http://www.pbase.com/bartenderdave/image/89184824 This photo is of the helm and cuddy access area (both finished, the former bright), with the floorboards in the foreground, with only resin on them -- no varnish and no paint. With varnish over the resin, the floorboards would have the same hue as the helm.

BTW, I don't use varnish any more. I use the two-part WR-LPU from System Three, for better durability, and easier application (in my hands; others hate this stuff and find it hard to work with; YMMV).

[CundysHarbor]

The only problem with staining wood before varnishing is that when it is time to scratch and patch, it is nearly impossible to dulicate the stain in those areas that need it. Better, imho, to go with plain old varnish.

[Richard Jones]

Thanks, all. Lots of good advice. Posts #4&#5 look like what I want. I'd rather not epoxy entire boat. I do love my varnish. And I know that to patch a scratch on a stained surface is a pain, but plain ol' occume needs something to liven it up.