Larry Martin explains how he uses water born dyes for coloring wood.
I use Transfast water-soluble dyes, a product of Homestead Finishing Products, Homestead Finishing Products On-line the minimum size is 4 ounces but retailers such as Woodcraft or Rockler the minimum is 1 ounce. The dye comes in powder form in small 1 ounce plastic bottles for $9.50, but that makes up an awful lot of dye.
The standard dilution is a 1 ounce by weight, that is a full bottle, into 2 quarts, that is 64 fluid ounces, of hot distilled water. To get a deeper color use less water. To get a lighter color use more water. Whatever you do, be sure to keep a record of the dilution you made up so that you can duplicate the color if you need more. There is no reason you have to make up the full bottle at one time, but the dissolved solution does seem to keep forever.
The different dyes weigh different amounts but you always get 1 ounce in the bottle, so some bottles have more powder in them and some have less. For instance, 1 ounce of the Light Oak dye fills 3 1/2 teaspoons, but (if I'm to believe my older notes) 1 ounce of Dark Red Mahogany will fill 10 teaspoons. For that reason it is not possible to come up with a standard dry measurement for making smaller volumes of dye. The dry measurement will vary between colors.
What I've done is to use a fine cooking scale to measure the weight of one teaspoon -- or even smaller amount -- and then proportionately reduce the water needed to dissolve the powder. For instance, 1 teaspoon of dark red mahogany weighs one-tenth of an ounce so multiply that fraction times the standard solution of 64 ounces to see that you need 6.4 ounces of water to produce a smaller volume of the standard dilution. For light oak dye, 1 teaspoon equals 0.29 ounces, so 0.29 times 64 equals 18.56 ounces of distilled water. When measuring smaller amounts such as one-quarter teaspoons or one-eighth teaspoon, I simply insert the measuring spoon into the dye powder, use a knife to carefully level the spoon and so that the excess powder falls back into the bottle.
For those on metric, 1 ounce is 28.35 grams, roughly 28 1/2 grams so one-eighth teaspoon is 3.5 grams, one-quarter teaspoon is 7 grams, one-half teaspoon is 14.2 grams, etc. The standard dilution of 64 fluid ounces translates to 1.9 liters. The examples used earlier of 6.4 fluid ounces and 18.56 fluid ounces translate to 0.19 liters and 0.55 liters respectively.
OK, so the first job is to mix up the color solution. The manufacturer recommends straining the solution through a fine mesh but I've never done that since the hot water dissolves the powder almost instantly. If you shake the bottle to mix it, be sure the lid is on tightly and is watertight because the dye can make a mess. If you get it on your fingers, I use hot water, soap and a kitchen abrasive pad to scrub my fingers. The sooner you do it, the easier the dye comes off.
Once you have the dye solution. raise the grain on the wood. This can be done by misting water from a spray bottle onto the wood, or by using a wet rag, not dripping wet which makes a mess, but wet enough to leave a light film of water on the wood. Let the water dry, may take an hour or so, then lightly sand the raised fibers with 220 grit paper, or the finest grit you used to sand the wood. I then raise the grain a second time in the same manner, and again lightly sand off the raised fibers. Now you're ready to use the water-based dye.
There are two major ways of applying the dye. One is to use a foam brush, dip the brush about one-half inch into the dye and then lay down an even coat is a straight line. Depending on how long your workpiece is, you may be able to go 2, 3 or 4 strips done before reloading the brush. Work rapidly but avoid laying too much dye repeatedly onto the same area. When you are finished coating the entire work surface I go back and even out the lines. I do this with the same brush but without reloading it. Now you have two choices, either immediately wipe off the wet dye with a lint-free cotton rag, or let it dry untouched. The first method with result in a slightly lighter color and possibly a more even color since you are wiping off any excess or pooled areas. The second method is less messy and will give you a slightly bolder color.
The second method of application is to dip a folded rag into the dye and rub it on the workpiece, either in straight lines or in a circular rubbing action. I don't use this method because I don't seem to be able to apply an equal amount of dye to all areas consistently, and because it is a bit messier.
Unless I'm after a very deep color, I apply only one coat. When the dye has dried, I use a maroon or grey abrasive pad to rub the surface smooth again to remove any dust nibs or raised fibers.
Then I apply two separate wash coats of shellac to seal in the color. I rub the finished surface with an abrasive pad after both coats. Then I apply a topcoat. Lately I've been using a wipe on polyurethane because it's been easy to pick up a can just a couple miles away at the Home Depot instead of making the 30 to 40 minute trip to Woodcraft. by Larry Martin