I have been using Transtint dyes for the past five years in my cabinet finishing.
My usual finishing schedule:
1. Sand wood to 150.
2. Mix Transtint per directions with distilled water.
3. Apply liberally on wood, with sponge, or rag, or foam brush. Thoroughly coat wood, to even out color as best I can.
4. Wipe off excess dye.
5. After dye is dry, spray on sealcoat cut 50% with alcohol.
6. Scuff sand with 220.
7. Apply gel stain.
8. After stain is dry, apply sealcoat.
9. Apply waterborne top coats.
Most of the time this method works very well. Right now, I am making samples for a project I am building of hard maple. The color to be is a golden to medium brown tone. I donít really like the way the samples are coming out, they are too blotchy after the dye goes on in my opinion, so I am looking for some help.
My questions are:
a. If I pre-wet the wood, with water before applying the dye, will that help? If so, how long do I wait to apply dye after wetting the wood?
b. If I spray the dye, can someone help me with technique on spraying the dye?
I have tried this a few times in the past, and I had a hard time trying to get an even pattern. I have read that guys recommend spraying several light coats, so how do you know when you have reached your final color? When flooding on the dye by hand, I can tell when the wood stops absorbing color, but with spraying I donít know how to tell, unless I spray it on heavy enough to have to wipe it off. I should mention that I donít have a spray booth, so I am limited to the water based dye. I also was wondering if with the dye the blotchiness is reduced by spray no wipe method? I appreciate any feedback!
From contributor K:
You are probably going to receive dozens of different methods on this and most of them will work; you just have to find which one works for you. Here are my thoughts:
1. Maple is a splotchy wood, no matter how stain/dye is applied directly to the wood.
2. Dye stains are meant to be flooded on. By trying to spray it on lightly, you stand the chance of streaking and uneven color, depending on your spraying expertise. The larger the project, the more difficult it can be to achieve uniform results. If you want a lighter color, thin the stain. Others may prove me wrong, but I personally don't think that pre-wetting the wood will solve the splotch issue (some areas will still be wetter than others). Having said that, maybe it would act much as a wood pre-conditioner does.
3. Using a water-based finish over a water-based stain can cause bleeding. The rule of thumb is to not use the stain and finish that use the same type of solvent.
4. You can try using a lighter stain as your base color, then add tint to your finish to achieve your desired tone. Using this method, it is best to tint the thinned finish less, and control the color by the number of (thinned) coats. Then apply your regular topcoat. Caution, it is easy to add "just one more tint coat", then find out that the piece now is too dark.
5. Test, test, test. The technique that appears to be ok on a 12"x12" sample piece may not work as well on a large project.
5a. I think that I would sand maple to 220.
When using a solvent like acetone, the solvent flashes off so quickly once it hits the wood that the dye does not have a chance to soak up into the open pore areas of the wood causing that blotching. If you want to use a gel stain after your seal coat go ahead.
This is one area where you have to practice on both solid wood and plywood as a veneer will take the dye different than the solid. I know that everyone in this forum helped me out a lot when I was in the same position as you right now. Practice and experimentation is key but I would limit the amount of water on maple and birch. I would go to a 180 or 220 before the dye. Pre-wetting isnít good, don't do it. I make a sample board and topcoat only half of it so you can see what the final color is as well as the dry stain color. Keep it beside you as you work. With acetone you can go back and tone your topcoat slightly if you are too light. Your spray pattern should be fairly high volume of air to finely atomize the dye. It should not be so low that you see large droplets (say 1-2mm is too large) it should look fine, not like drops.
Grit size is used by some as a color control - the finer the grit, the lighter the color for a given stain. This holds true more for pigmented stains than dyes. As the sanding scratches become smaller and finer, there is less area for the pigment to lodge in. Personally, I seldom rely on this method; since I almost always do toning after staining, that becomes my method of color-control.
One might ask, "If 220 is good, won't 400 (or 500, 600, etc) be better?" The answer is, "No." At some point you will start burnishing the wood - sort of creating a barrier against stain absorption and adhesion. Since the burnishing would be uneven, the resulting staining would be uneven, and the results would be un-satisfactory, and the customer would be unhappy.
2. Water dye is useless on maple use spray NGR. You can still use the Transtint but you need an acetone/glycol ether solvent mix. 8 parts acetone, 1 part butyl cellosolve and 1 part glycol ether PM.
3. Spray using an HVLP gun at low pressure - 5 psi at the aircap which for most guns is 15-20 psi at the gun.
4. Spray in multiple light passes. Never have liquid dye sitting on the surface.
5. With this method maple can be stained as dark as you like with perfect uniformity.