I'm assuming you are talking about model maker's Birch ply. the wood conditioners mentioned are a good idea and where I would start. then seal the wood with a thinned acrylic varnish and sand lightly. coat and/or recoat sufficiently to close the pores, but not entirely, leave surface still porous enough to accept filler . Use a thinned water base wood filler, Elmer's interior wood filler is good, has a nice neutral color akin to boxwood. Thin with water and wipe on, filling the the grain. wipe off excess with a damp rag. Do not be too aggressive. A couple of passes. allow to dry in between. The Elmer's is water soluble and can be reworked ad infinitum. Allow to dry thoroughly and sand lightly until surface is smooth. a patient gentle approach with fine sandpaper, 150-250 grit or so. Use patience until a pleasingly soft tactile surface is achieved, still porous enough to hold glue and colorants. Seal again with thin satin or flat acrylic varnish. sand lightly in between a couple of very thin coats.( Or as many as are required to achieve the surface you want.)
Most old Admiralty models with exposed wood are boxwood which is a creamy, smooth pale yellowish (emphasis on the "ish") color. You may already be there at the end of this process. The ply edges will probably require an opaque coating to approximate the flat surfaces after having been treated in the same way described above.
For further coloring I recommend glazing with artists oil colors ( of which there are an infinite variety of colors) thinned with the appropriate artists oil solvents. This is slow, but has the virtue of being malleable, with a long working time.
and is reworkable if desired. Japan drier can be used to speed the process, but remember ,speed is not the objective here, patience with yourself to acquire the required technique is. I like to use old soft cloth as an applicator, sometimes in combination with brushes.
Also prior to this , a few very thin coats of amber shellac (50-50 denatured alchohol to shellac) lightly brushed on, will impart a warm glow ,either as a final look , or a golden glow beneath glazing which adds depth to the final finish. Once thoroughly dry, an artist's (thinned) varnish will seal the colored surface.( fat over lean , never lean over fat.)
Purchase a sheet of modeler's ply wood, cut into 4 to 6 inch squares to experiment on. keep a recipe log of each, so that you can reproduce any desired result.
I bet there is a U-tube video on glazing, which is ,in short, the process of laying one translucent coat of color over another, using either a brush or a rag.
Remember, the final surface must still be porous enough to hold glue, not shiny.
I am, as you may have surmised by now ,Old School. also, feel free to contact me at
petergutterman@yahoo.com (if this is considered kosher at SOS). let us know what your results are if you stick your toes in this water. Lots of experimenting before you commit.
Good luck.
Pete
These are some images that I meant to share, just now uploading.
the model is an 18thc. Spanish ship of the line, "El Terrible" that I have been restoring for Roger's collection at The U.S.N.A. museum. The bulkhead was recreated from birch plywood cut out with a laser. The birch ply was used for its ability to hold up accurately cutting a multitude of tiny parts. It was finished to match the late !8th c. original wood using the method I described in my earlier post. Also, I employed glazing in matching repairs to the original finish, in particular the hull bottom. I used a pencil to recreate the crackle in the finish of the bottom where necessary.
