|
The following shop note by Eugene Larson
appeared in the Nautical Research Journal, Volume 43, Number 1,
March 1988, Page 61
Commercial wood fillers come in
many different textures and colors. Fine-grain fillers are excellent for
filling gaps in wooden models. However, there is one major drawback. If a
natural or stained finish is desired, commercial filler colors seldom match
the wood in the model, and the filler's finished appearance detracts from
what may be an otherwise excellent model.
I have found that saw- or
sanding dust from the wood being used in a model provides the best color
match. Of course, the wood's grain is not replicated in the filler, but
when fine-grained woods like box and pear are used, grain is barely evident
anyway. To use wood dust as a filler, a finishing
oil like tung oil works well as an adhesive. Glue
used as an adhesive is strong, but it hinders the penetration and coverage
of stains, oils, varnishes, and other applied finishes. Tung
oil will probably be consistent with the finishing material. In fact, I
prefer to use tung oil for the finish on models
and cases. It is easy to apply, gives a deep rich appearance, and is easy
to recoat and repair.
To make the filler, mix wood
dust and tung oil to a thin consistency. Prepare
plenty so you have enough. A margarine tub lid makes a good mixing pallet.
Apply the thin paste to the gap with the flat of a screw driver, a stick,
or a tooth pick. Let the filler dry for a day, then
lightly sand the area to remove evidence of tung
oil that might have migrated onto the surrounding wood. One application
should be sufficient.
The method is especially useful
for finishing baseboards and wood cases. Cherry, for example, has beautiful
grain, but often there are tiny sap pits that blemish the surface. To
assure that the surface of the blemish is fair with the remainder of the
backboard, sand the surface with 240-grit black wet-or-dry paper used dry.
Do not dust the surface, and be sure the sap pits or other blemishes are
full of wood dust. With a tooth pick, apply a drop of tung
oil to the dust in the blemish. The oil will probably run onto the adjacent
wood, but this is not a problem. As soon as all the blemishes are treated,
sand again until the oil on the wood surface has disappeared. Repeat as
necessary until a good filling is obtained. Tung
oil, when dry, is adhesive enough to hold the wood dust in place;
subsequent coats of finish help, too. The final finish will be smooth, but
the sap areas will remain evident, which is desirable because they add
character to the wood.
Sometimes the end grain of base
boards is rough, especially if a shaping tool was used to mold a decorative
edge and some wood fibers are torn. In this case, the filler is effective
for filling the voids. Allow the treatment to dry for a day before sanding.
A little experimentation should produce excellent results.
Copyright (c)1998, Eugene L. Larson
|
