|Start your project confidently and get the answers|
to some of the most frequently asked questions
regarding wood staining.
|"I am refinishing one of my interior doors. As I wipe off the excess stain, I notice a bunch of white spots on the door. Also, as I sand the door, more white spots begin to show up. Its as if some parts of the door absorbed the stain well and other parts didnt. Is this caused by the door itself or the sanding? How do I fix it or can I fix it?"|
Without a better explanation of what you mean by white spots, it is impossible to guess for sure what you are witnessing, but there are several common problems associated with refinishing that could fall into the category of what you describe.
Often, islands or spots of finish are left impregnated in the wood during an incomplete stripping of the old finish, and these areas will block stain absorption. This is particularly common when the finish is sanded off rather than removed with chemical strippers. Contamination, such as wax residue from some types of paint remover, can do the same thing. Ive also seen people sand through a surface veneer into the glue layer holding it to the substrate. This glue layer will also resist stain. Finally, some large pore woods are prone to collecting sanding dust or swarf, which may show up as white areas, and more sanding can create more swarf.
The best bet in this case is to seal the wood prior to staining, then use a 100% pigmented stain, which is more likely to color evenly over sealed wood. (Varathane makes a line of premium 100% pigmented stains.)
At this point, as you are halfway through the job, let the stain dry. Do not sand or abrade anymore. When the stain is dry, re-stain selectively, adding color only to those areas that are lighter until they match the hue of the rest of the door. You can also apply your first coat of clear finish over the stain, then use aerosol cans of tinted lacquer to blend the colors. Youll find them at woodworking specialty stores that carry the Behlen line, and online at Mohawk-Finishing.com.
|"My oak dining table has a rustic design with grooves ( saw cuts) in it. Spills fill the cracks, and then my wife goes crazy trying to clean the gaps with a tooth pick. Could you please recommend a finish that will fill these gaps and make it easier to clean?" |
An ornamental groove (called a "reveal" in woodworking lingo) is generally too big to be filled with finish. However, you can fill the grooves with putty, such as "Plastic Wood," sand it smooth, and finish over that. The process is similar to filling gouges in wallboard with Dap spackle.
Choose a putty that is similar in color to the wood, if you want to minimize the reveal lines, or a contrasting color if you want them to stand out. A darker or lighter color will make them look like lines of inlay. Thin the putty so that it is a consistency thats easy to work with, using water for waterbased putty, and mineral spirits or lacquer thinner for solvent based putty. With a broad putty knife or wallboard knife, force the putty into the grooves, scraping it off the flat areas at the same time.
Fill the grooves so they are just slightly proud of the surface, since the putty will shrink a bit while drying. Let it dry completely (this might take more than a day), then sand it flush so that there is putty remaining only in the reveals, and not on the rest of the tables surface. Once the surface is sanded level, continue with your finishing schedule.
|"I recently shellacked a kitchen table, because it was easy and did not smell. However, now I know that shellac is not very water resistant or heat resistant. What should I do?"|
Actually, it is quite water resistant, but it is not heat resistant. Add a thin coat of Zinsser Seal Coat, and when that is dry, add two or three coats of either oil or waterbased polyurethane. That will give you heat resistance as well as water and stain resistance. While polyurethane will not go over normal shellac, which contains wax, it will go over SealCoat, which contains only de-waxed shellac.
|"Help! I am staining a pine end table top and the stain is very blotchy. After the first layer of stain, I tried sanding over the light blotches and using steel wool on the darker areas. The second coat of stain darkened the lighter areas, but it still looks blotchy." |
Let the stain dry, then re-stain selectively, adding color only to the lighter areas. Do not sand or steel wool between coats of stain, as that will only exacerbate the problem. Youll find that with a deft hand, you can make it all come out even. Once the color is uniform, add your clear coats.
I know you did not ask, but please allow me to show you where you went wrong, and what you should have done, so as to prevent the same situation in the future. Avoiding the problem is much easier than fixing it, and the technique is quite different.
If you suspect that a wood will blotch during staining, and if you are using an oil based stain, treat the wood first with "wood conditioner." This is a clear liquid meant to go onto raw wood only before the first stain is applied. (If you re-stain a second time after the first stain coat is dry, there is no need for a second application of conditioner.) Wood conditioner works only while it is still wet, so flood it onto the wood, wipe it off, and stain immediately thereafter. Do not wait until the conditioner is dry or it will not work. Wood conditioner will make the wood stain more uniformly in cases where it is likely to be blotchy. Which woods are likely to do that? All softwoods (pine, cedar, etc), cherry, and sometimes maple, birch, or poplar.
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