Tuesday, June 15, 2010

Staining blotchy woods like cherry, pine or maple.

In my years as a cabinet maker I have repeatedly tried to get an acceptable finish on maple, cherry and pine, all of which are tough woods to stain easily. The bottom line is they look blotchy when you use Minwax stain right out of the can. One obvious solution is to use Minwax's Wood Conditioner on the wood first as a pre-treatment. First you apply the conditioner to the freshly-sanded wood and wait a few minutes for it to dry to the touch. Next you apply the stain over the conditioner. I am not sure why you have to stain right after the conditioner is applied but it must have something to do with how they work together. Other companies make conditioner but just to be safe I would suggest using the same company who makes the stain although I doubt it makes a huge difference. This method works reasonably well but one thing I notice is that unless the wood is sanded properly this method will come up short and even if it's sanded well it could also leave you disappointed. The bottom line is that it is better than not using it and for most homeowners and clients that's "Good enough".

Not one to settle for just "Good enough", I learned a nice trick from an old timer called "Spit Coat". What this amounts to is basically applying a clear finish on the bare wood before applying the stain. You don't want to use polyurethane as the Spit Coat though as this will not work too great and it takes a long time to dry. They key is to use a mixture of 5 parts denatured alcohol to 1 part shellac. There are a few kinds of shellac including one that is tinted amber for a darker color and one that is more clear. Shellac even comes in dry flakes that are dissolved in a solvent before using. Bullseye makes a good pre-mixed shellac so I prefer that. Mix up the 5 to 1 ratio and you can apply it directly to the wood. Shellac adheres to just about any surface except waxy surfaces so it is commonly used in primers. Shellac dries real quick so you can plan on staining within a few hours (or sooner). Next you can lay down a nice coat of stain after you lightly sand the shellac. I would also use a tack cloth to clean off the sanding dust. If you are doing any quantity of trim save yourself some aggravation and avoid the cheap throwaway brushes. They are junk and they shed their bristles and don't lay down the stain very well. I think foam brushes work ok but the best brush I have used is called a Shipmate made by Elder and Jenks. It is a 100% white China bristle brush which is much finer than the black china bristle brushes. Never use a cheap nylon brush because they are not compatible with alcohol and they can dissolve.
The stain can be applied and left to sit for a while before wiping off or can be left on and not wiped off at all. My choice would be to wait several minutes and wipe off the stain and then apply a 2nd coat of stain. This just makes the finish a little richer in appearance. Obviously the longer you leave the stain on the darker it will be. I would suggest testing a few pieces of scrap wood first to get the color just right. Once you are satisfied with the color you will need to let it dry overnight before starting the final coats of finish. You have several different options for the clear finish coat but most people use polyurethane which comes in a few different sheens such as matte, semi-gloss and gloss. You can always start with the more dull finish and work up to the gloss but it's not a good idea to start with a gloss and work down to a matte finish. So if you are not sure how shiny you want it you can start off with the first two coats matte or semi-gloss and then do the last coat in gloss if it's not glossy enough. Again, it is imperative that you use a good white china bristle brush to get a good smooth finish. Avoid the foam brushes for a good finish because the foam introduces too many air bubbles into the surface of the finish. NEVER EVER shake up the polyurethane before you use it. Stir it slowly because shaking it will fill the finish with bubbles resulting a terrible finish.
If you wish to skip all these extra steps, my advice to you would be to avoid using a stain that is much darker than the natural wood color. Using a dark stain on maple is certainly not going to look good. With the cherry it is helpful to know that it will naturally darken considerably over time so if you are patient you can get that rich cherry look without stain. It'll just take a few years. Cherry oxidizes in the presence of air (and sunlight) and that is what causes it to darken. If you set an opaque object on a piece of cherry and sit it outside in the sun for a few hours, there will be a lighter colored area where the sun did not darken it under the object. Sometimes people set cherry outside in the sun to accelerate the aging before finishing. After a few days in the sun it will darken quite a bit. It is very difficult to predict the final color of cherry so try not to introduce too much color. If you do you might be sad in a few years when you discover how dark your kitchen is.
For a little background info on Shellac check out this link http://www.naturalhandyman.com/iip/author/zinsser/shellac.html
Here's another related blog with some photos showing the process