Michael Dresdner

straight talk about wood finishing

Not always the answer you want to hear…

Q: My floor is half sanded with some shiny areas and some bare wood. Do I have to remove all of the old finish before refinishing?
A: Yep

Q: I recently made an octagonal table top out of leftover red oak flooring. I wiped an oil based red mahogany penetrating stain on the sanded, raw wood. When I put on the second coat there appeared one strip about an inch wide where the stain just wiped off leaving an unsightly light area in contrast to the deep color of the rest of the table top. There is some variation in color and shade, obviously, from board to board, which I expected and am fine with, but this area is almost the shade of the raw wood and sticks out like a sore thumb. What can I do?
A: The easiest way to blend colors after staining is with tinted topcoat applied between the first and second coats of clear finish. You can mix your own or buy some finishes, such as polyurethane, already in tinted form, both in liquid and aerosol versions. Some companies, like Varathane, match their tinted polyurethanes to their wood stains, making blending a fairly easy task.

Q: What is a good, sprayable gloss finish for a bass guitar made of several woods?
A: Lacquer is certainly the most user friendly for instruments. It is easy to apply, repair and buff, and it dries quickly. Because you are using multiple woods, it would be wise to seal the instrument first with one coat of Zinsser SealCoat.

Q: How do I stop the oil from coming out of woods like wenge, cocobolo and rosewood when I apply lacquer?
A: The term oily wood is a misnomer. While some woods are highly resinous, there is no oil in wood, so there is no oil to come out. Some woods may bleed color, meaning the color can migrate into the lacquer. Usually, that’s not a serious issue, but if it is, seal the wood first with a coat of Zinsser SealCoat. Once it dries, it should block further bleeding. Incidentally, wenge is neither particularly resinous nor likely to bleed, though the other two, both of which are dalbergias, are resinous and will bleed color.

Q: I plan to sand interior mahogany doors with 180 and 220 grit, stain one coat, let it dry, sand it with 320 grit, then apply three coats of polyurethane, sanding between these coats with 320 grit. After the final finishing coat, let it dry and cure for one month then follow your recommend scrubbing process, sanding 1000 grits and 000 steel wool with paste wax and then buff it with buffer. Is the right process for interior doors?
A: Nope. Let’s go through this a step at a time, starting with sanding. Unless someone else already sanded the door to 120 or 150, you need to start with a coarser paper than 180. Typically, we start sanding at 80 and go up from there. You can stop at 180 garnet, or 220 AlOx.
Stain should be flooded on liberally, then wiped off completely, leaving only what the wood has absorbed. Never sand after staining, since it will remove the stain you just applied, and do it unevenly at that.
Once the stain is dry, apply your finish at the rate of one coat per day. Sand between coats only if you need to in order to smooth roughness, dust nibs or brush marks. Otherwise, sanding between coats is not necessary as long as the next coat goes on the next day.
To rub to satin, wait a couple of weeks, remove any dust nibs with 400 or 500 grit paper, then rub with the grain using 0000 steel wool lubricated with paste wax. For gloss, wait six weeks, sand through the grits from 600 to 1200 or higher, then rub with automotive rubbing and polishing compounds.

Q: I am trying to refinish an oak floor that is in a home built around 1960. It has a clear finish, but when I start sanding with the ezV sander, the finish clumps, sticks to the sandpaper and clogs. I have no idea what the finish is, but I am looking for suggestions on removing it so that I don’t have to stop every couple of minutes and scrape the flakes off the sandpaper.
A: The ezV sander is very user friendly, but not very aggressive. You might want to switch to a more aggressive type of sander, such as a drum sander, to remove the finish. That allows you to use a coarser paper at first, such as 24 grit. There’s no easy way to avoid clogging if you are removing a soft finish, but there are methods other than sanding. For instance, scraping off the finish with a ship’s scraper, then sanding afterwards, is more labor intensive but less frustrating. The same is true of stripping the floor first with paint remover; messier and smellier, but it does eliminate clogging expensive paper.

Michael Dresdner
www.michaeldresdner.com
Metaphors be with you.