I have a request to build a small dark coffee table. I want to use either walnut or mahogany. However, I cannot find a finish recipe which will hold up to the extensive sunlight where the table will be placed and continue to be a dark wood. I still want to see figure and depth in the finish.
Any suggestions.
ps. The recipes I found to warm up walnut contain dyes, which are said to fade over time in direct sunlight. A pigment stain is fade resistent, but don’t know how it would look and if it would cover up the figure and depth of walnut or mahogany.
Replies
>> I cannot find a finish recipe which will hold up to the extensive sunlight where the table will be placed
Basically there is no clear finish that will work for a much longer than a year. Us boaters wish there was. UV inhibitors put into some marine exterior finishes will lose their effectiveness in about a year. Pigment stains do hold up longer than dye stains but they too, will fade after a few years.
What non clear finish would work?
>> What non clear finish would work
Paint. The more opaque, the less the UV penetration.Howie.........
First a question. Is this sun-drenched location inside, with the sun coming through glass, or is it outdoors with direct unfiltered sun?
Ordinary window glass blocks about 30% of the UV light, and low-e glass even more, perhaps 70% of the UV. Wood and dyes will fade in either case, as will fabrics, but there is at least a prospect for keeping a finish intact, especially with the low-e glass. If important enough, there are glazing solutions that reduce UV even farther.
Pigmented stains, used carefully, can be used on these woods without an adverse impact. They would have to be used over sealed or partially sealed wood. That way, they mostly lodge in the pores, and can even enhance the appearance of grain.
The two woods will behave differently. Walnut will begin to lighten fairly quickly. Mahogany will initially darken, and then fade. After a century they will look very similar to each other. The faded look of the woods after long periods can be quite elegant. It is sometimes the charm of fine antiques. Sometimes we need to accept those things that cannot be changed.
The table will be inside, but I doubt the glass is anything special. Do you have a sealer, pigment, glaze formula I could try on a test piece of mahogany?
I would use a 1lb. cut of dewaxed shellac as a seal coat. Then I would use a pigment only oil based stain. I mix them myself, starting with some varnish as a binder to which I mix japan colors or good artists oil paint for the pigment. For mahogany I use a mix of burnt umber and burnt sienna. Vary the proportions to vary how red it will look. The umber is brown, the sienna is more red. Thin to a workable consistence with mineral spirits. Apply like the typical stain, though since this doesn't have commercial additives, make sure you keep it well stirred. Apply quickly and liberally, and wipe off as usual. You can vary how dark the finished result is by varying the cut of the shellac. Leaving more stain on the surface for extra darkening will obsure more of the grain. You should be able to work out the variations on test boards.
If I weren't avoiding dyes, I would have started with a lemon yellow dye, seal that with the 1 lb. shellac, and then apply a fairly dilue brown mahogany dye, again seal that with 1lb. dewaxed shellac, and then apply the pigmented stain to deepen the color in the pores.
I like a dark shellac as a top coat. Shellac coloration is quite stable over time.
Edited 1/18/2006 10:08 pm ET by SteveSchoene
I will give it a try. What is the easiest (most foolproof) way to apply shellac.
Having had my cherry dining room table bleach due to being at the window, I will tell you that the only answer is shutters or a cloth. The sun will bleach it.Gretchen
Steve,
The recent issue of Wood has an article that also recommends applying yellow dye as a foundation for the process. Color mixing/matching is a true mystery to me so what is the reason for the yellow base. Is this primarily for reds/browns?
Doug
The yellow dye serves to create a subtle golden highlight that shines out under the browns and reds of the main coloration. It replicates a bit of the look of antiques and adds richness and complexity to the finish. It may reflect the long-term fading of the mahogany used in those antiques.
Gretchen:
I absolutely agree that the wood will fade without much more UV protection. As I said in may earlier post the fading is part of life. The pigment in the stain won't fade appreciably and will moderate but not eliminate the color change, unless it is used so heavily as to actually be a paint. Of course the table doesn't have to be bolted to the floor in front of the window. In the coming decades it may find many places to live.
I hope to build a retirement home sometime in the next decade and am already planning for UV protecting windows in the "parlor" where my formal reproductions will abide.
Thanks STeve. I rarely work in the darder tones but I will definitely try this on my next walnut or mahogany project.
Doug
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