Dye Stains, Solvents, and Alder
A question about spray dyes for Alder leads to a discussion of sophisticated custom formulations using dyes and solvents. March 26, 2007
Question
I am having trouble getting an even color using Transtint dyes mixed with alcohol on alder. I sanded the wood to 220 then used Target waterborne shellac cut 20% with water as a wash coat. I sanded that back, sprayed on the stain and wiped off the excess. The color is okay for the most part, but what really concerns me are these small rings of dark color around the larger pores. This looks very unnatural to me.
Forum Responses
(Finishing Forum)
From contributor T:
Alcohol dye over an alcohol soluble wash coat that's been sanded back? The alcohol in your dye dissolved or partially dissolved and mixed with the shellac left in the pores and reset before you wiped it down. A good scrub down with alcohol should even things out but you may have to mix a little of your transtint with your shellac and give it another very thin coat or two to get your full color back. If you like that schedule and want to use it in the future, I'd suggest: raise the grain, sand, dye, seal… Or raise the grain, sand, seal and color with dye tinted shellac.
From the original questioner:
I am mostly just looking for a fast way to stain a house full of alder cabinets. Any schedule or other insights would be greatly appreciated. Keep in mind I will be using Target waterbased coatings.
From contributor D:
You can use whatever coatings you wish over the dye stain, but the dye should be methanol or acetone based and sprayed on in layers to achieve uniformity and avoid all tendencies to blotch. I've invented a solvent mixture that works great with the Transtint concentrates made from 8 parts acetone, 1 part butyl cellosolve and 1 part propylene glycol monomethyelther, also known as PGME, or 1-methoxy-2-propanol. This is sold by Sherwin Williams specialty coating stores as PM Reducer (R6K34). This mixture is safer than the traditional mixture of methanol and Butyl Carbitol, which also works very well. Using this solvent mixture and Transtints, you can stain alder beautifully, quickly and uniformly. Much better than you will ever achieve with a pigmented wiping stain.
From contributor D:
Point I forgot. You should never wipe excess NGR stain, as there should never be excess NGR stain on the wood to begin with. Build the color in coats and avoid wiping altogether. Wiping NGR is a sure fire method to achieve a disaster. Cut the material flow of your spray gun way, way down. The wood should never even get wet as fast as this stuff evaporates. Think of it as applying films of color. Done this way, dye stains are amazing.
Another point I forgot is that you shouldn't spray an NGR dye over anything. It goes directly on the bare wood. There is no point to shooting it over a sealer coat of anything except glue size, which is permissible in certain circumstances such as truly blotch prone cherry.
From contributor Z:
I stain alder with a wiping stain with good looking results. No wash coat. Never been a fan of wash coats. If you want to stick to a dye stain. I use a system like contributor D. I use Transtint in a spray-no-wipe base. I get my color halfway to what I want, then seal. I add the same Transtint to my clear, cut it in half with thinner, build a little more color, then clear instantly. I use this system for maple mostly.
I don't save any time using spray-no-wipes versus wiping stains. I spray my wiping stain on and wipe off like a mad man. I take my time on snw to make sure everything is coming out the same color. If you're doing this on site, consider using a wipe stain. Might be best in the long run.
From contributor M:
That's some good advice worth saving. Alcohol dries too fast to be wiped unless it used on small pieces. Keep the gun in motion and do not flood it on, watch for the stain to dry, and then start back where you started out. You might want to thin out the stain if it's too dark, and make a few extra passes to bring up the color. Starting too dark can cause you problems. Do some testing to get familiar with the technique.
From the original questioner:
Thanks for the great advice on mixing Transtint with your solvent mixture! Just what I was looking for. I have a Jaguar slp hvlp 1.0 n/n and an
Astro 4020 1.0 n/n. I will try them both and see which works better.
From contributor T:
Contributor D has given you some great tips, but recognize that his solvent mix is a knocked down lacquer thinner that is heavy on the acetone end. You can spray that in CA?
If you're dedicated to WB, you're going to raise the grain at some point, so why not start by raising it and then staining with a water based dye? It would give you a less expensive, more colorfast solution and you wouldn't even need a spray booth.
From contributor P:
I second contributor T's advice. I use TransTint or Lockwood water soluble dyes, then seal with dewaxed shellac. I use Zinsser shellac, not Target. The alcohol-based shellac will not re-dissolve the dye. I use WB (Target, Fuhr, etc.) over that.
From contributor M:
It's become a common practice when using the WB systems to use the dewaxed shellac as the sealer over the stain, followed by the WB coatings. This eliminates sponging with water to raise the grain. Shellac does not raise the grain as the WB coatings do.
From contributor E:
Contributor D, does your mix provide a better, more even appearance than mixing the Transtint into alcohol or shellac? I have benefited from many of your posts in the past, particularly where you mentioned mixing Transtint with shellac to dye stain and seal in one easy step. I know that he put his alcohol Transtint on top of waterbased shellac rather than directly on the wood.
From contributor D:
To make an NGR base you need a mixture of evaporation rates. Ideally it would be pure acetone, as acetone is an exempt solvent, but this doesn't work as the dye doesn't penetrate into the wood at all - it simply lies as a powder on top of the wood. So you need to mix a majority of acetone with a very slow glycol ether like butyl cellosolve so that the dye penetrates into the wood. The purpose of the PM Reducer is that this is the true solvent for Keystone Aniline’s Nerosol dye concentrates and Transtints. You need this to keep the dye in solution and not have it precipitate.
From contributor T:
Transtint dye precipitates in acetone? Didn't make sense, so I tried it. Couldn't make it happen and when I used it - it stained the wood very nicely. Water, alcohol, acetone and glycol ethers are miscible. So I would expect something containing glycol ether and recommended for reduction with water or alcohol (Transtint) to be also miscible in acetone. Yes, acetone is very volatile and if you use it, you would probably benefit by adding some butyl cellosolve, but it still stinks and spraying it requires a spray booth or the great outdoors. Why not stick with alcohol? It doesn't stink, isn't as volatile, and can be sprayed with adequate ventilation. Or how about water - it does raise the grain, but doesn't smell at all, isn't nearly as volatile as even alcohol, and it's cheap. Contributor D has given some good advice on applying dyes. But if you use Transtint, stick with the recommended reducers: water or alcohol. (This is not true for all dyes.)
From contributor G:
We used to make a very nice spray stain using Arti colorants and a base of denatured ethanol with about 5% resin added. VPM naphtha with a touch of added resin is a good spray stain base as well, but I don't know how that stacks up in the VOC department. Just offering other ways to do things - I see nothing wrong with contributor D's chemistry.
From contributor G:
Or is it Varnish Makers & Painters?
From the original questioner:
Thanks to everyone for their feedback. The alcohol base stain was very blotchy on raw alder, which was my reason for attempting the wash coat in the first place. I have tried putting the dye into my waterbased shellac sealer cut down about 10% with water and had some pretty nice results, however I would still like to see a little more grain definition from the stain.
From contributor G:
If you are not getting enough grain pop from the shellac, perhaps you'll have to wipe your stain.
