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| Leave it to the pro. Michael Dresdner, a nationally known wood finishing and woodworking expert, has answered hundreds of common wood finishing questions in Varathane’s Q&A library to help you successfully complete your project. Click on a link to the left for help and solid advice. |
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| "Do you have any suggestions for hiding/minimizing the appearance of
larger knots before applying a stain and clear finish?"
You can patch them either with wood or putty, or "paint them out" prior
to staining.
I have to admit that I find the question odd, since knots are part of the
figure of wood, and part of what makes it nicer than plastic. However, if
you need to remove them, there are several ways, all of which will leave
some visible evidence of your tampering with nature.
One method is to rout out the surface of the knot about .035" deep, and
inlay a patch of veneer that matches the rest of the wood. Called a
"Dutchman" in the old days, these patches can be any shape, but football and
amoeba shapes are often easiest to hide. Naturally, you want to line up the
grain and color on the patch to match the surrounding wood.
If you are adept at touch up, create a shallower void and fill it with wood
putty that is the color of the very lightest value in the wood. Once it is
dry and sanded flush, paint in some grain lines to hide the putty patch.
Another method, that avoids routing, is to carefully paint over the patch
with artists colors to match the color and grain pattern on the surrounding
wood.
All of these methods will show to one degree or another, but a dark, 100%
pigmented stain, or a lacquer toner, will hide them better than a light
colored stain or a dye stain. |  | |
| "My biggest problem is grain filling the backs of my guitars which are
made from porous woods. I have been using a water based grain filler under
spray lacquer and following directions, but after 2 months the grain sucks
in and becomes visible. What product would you recommend? Also, lacquer is
too soft and takes too long to cure and I tend to apply it too thick. For a
novice, what product and procedures do you recommend for a finish that
sands/levels easily, cures fast and hard, and cleans up easily?"
You have described just what you are using - nitrocellulose lacquer. It
is very user friendly, sands easily, and cures fast and hard, relatively
speaking. The only finishes that cure faster and harder are two-part
crosslinked coatings, and there are too many trade-offs involved for them to
be right for you. Instead, you need to learn to slow down and be patient.
Apply the lacquer in thinner coats, no more than one coat per day, and you
will have fewer shrinkage problems. Wait at least four to six weeks after
the last coat before buffing the finish to gloss.
As for the pore filler, I find the Behlen waterbased pore filler to be quite
good. You will get better results if you fill over wood that already has one
coat of sealer on it.
Seal the wood with a coat of Zinsser SealCoat, and when it is dry, go to the
pore filler. Thin it to the consistency of heavy cream, and scrub it onto
the wood. I use a piece of Scotchbrite as an applicator, as it helps pack
the material into the pores. Once the filler is on, immediately squeegee it
off using a piece of plastic or a credit card. Hold the card at right angles
to the grain, and draw it in the direction of the grain. That will remove
all the pore filler except what is lodged in the pores. Let the filler dry
overnight, then sand with 220 or 320 grit paper to remove any residue
outside the pores. Reseal the filled wood with a second coat of SealCoat.
Let it dry, then move on to your sprayed lacquer coats. | | |
| "I would like to re-finish a bookcase. It appears to be made of particle board with a real wood veneer. I thought that the best way to do it would be to use a chemical stripper. At the local home improvement store, they said that a chemical stripper might damage the veneer and instead recommended sanding with a 120 grit paper. I don’t think this is going to be a good option. How would you recommend that remove the old polyurethane coating?"
Trust your instincts. You are correct, and the home improvement store clerk is wrong.
If, in fact, the piece has real wood veneer, you will quickly sand through it trying to sand off a finish. However, no chemical stripper will harm any veneer. Strip it chemically, and avoid excess sanding, since it is very easy to sand through a veneer.
One word of warning is in order. Many cheap particle board creations look as if they have real wood veneer, but in fact are covered with a printed vinyl film, over which finish has been applied. These photographic films are very convincing, and some even have textured wood pores cast into them. If this is the case, any stripper that will remove polyurethane will also melt the vinyl. There is no practical way to strip such finishes, and the only way to make them a different color is to spray over them with tinted shading or toning lacquer, or add stain (glaze) on top of the finish, then add more clear coats. | | |
| "I intend to clean and finish a type face frame to hang in my office. I am using a Dremel tool to sand out the dirt, but it doesn’t reach the tiny box corners. Is there a better way? I want to finish it in a dark cherry color. What should I use, and how should I apply it?"
Those flat trays full of a multitude of little compartments are actually called "fonts." In the days of linotype, one font held an entire set of lead slugs, each with a letter on it, that made up one typeface. As a result, the word font came to mean both any particular typeface, and the box that held it. These days, a font or typeface is stored as a program in a computer, making those wonderful trays widely available, often for very little money.
Because they once held lead slugs, the dirt in them may well be lead dust. There is no easy way to sand it out, and yours is as good as any I can think of, but please be aware that sanding lead dust can be hazardous to your health. Make sure you are wearing a good dust mask, and when you are done, vacuum up all the dust and wash yourself and your clothes.
Staining it will be easier, but I would definitely use a pigmented stain (such as Varathane Premium) rather than a dye or pigment-dye combination stain, since it will help hide some of that hard to remove dirt in the corners. Apply it by working with two brushes, one wet, and one dry, and some paper towels. Brush the stain on with one brush, wipe off as much as you can, then use the dry brush to pick up excess stain in the corners. Wipe this dry brush as you go with a clean paper towel to remove the stain from it. In this way, you will be able to stain evenly without leaving puddles of stain in the corners. The fact that there are lots of little recesses will make this a fairly tedious job, so stain one small area at a time, remove the excess, then move on to stain the adjacent area. Do all the inside areas first. Then, if you need to, you can sand the flat frame and the top of the grid and restain it to get rid of any lap marks. |
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