Using Pigments for Glazing
A discussion of mix-your-own glaze techniques, covering binders, solvents, and pigments. April 9, 2007
Question
I have used Hulls 844 pigments for making pigmented lacquers. Can they be used as glazing pigments? They dissolve in lacquer thinner, but not denatured alcohol or mineral spirits.
Forum Responses
(Finishing Forum)
From contributor G:
You can indeed use 844s as glazing pigments. They are, after all, pigments. You should select an appropriate vehicle for the pigments. They don't dissolve in anything at all, since they are pigments, but will disperse in a number of solvents. Sometimes you have to mix them in LT and then into the alcohol, but they are universal tinters and should blend with almost anything.
From contributor R:
Some glaze bases will accept the 844's as the coloring pigment. Check with the manufacturer of your glaze base - MLCampbell does. Do not use the 844's alone, without a base.
From the original questioner:
We tried with LT and it went well, however it bit right into the vinyl sealer. That's why I was looking for another vehicle. Thanks, though - I will try MEK and acetone tomorrow.
From contributor G:
Maybe try using untinted glaze base as your vehicle.
From contributor T:
You need a glaze base. 844 and solvent alone will not get you a glaze. You need to add your 844 to a binder (aka glaze base). That's what you did when you added 844 to lacquer to get a pigmented lacquer toner. Pigment/binder/carrier. With 844 and solvent, you've got the pigment/carrier part, but you're missing the binder part. If you don't want it to bite into your sealer, don't use a binder that uses either acetone or LT as a solvent.
From contributor D:
824s are what you need for a quick dry glaze using mineral spirits or naphtha. 844s won't work in these solvents, but I guess you found that out already.
From contributor M:
Give this a try... glazing. Try a small sample. First try adding some BLO or tung oil into the colorant, try to mix it in. If it goes in, then try adding some mineral spirits. You can also try mixing the colorant into either toluene or xylene with the colorant - both of these solvents are compatible and should work with the lacquer thinners.
From contributor J:
Sherwin-Williams sells a glaze base that you can put any colors you want in.
From the original questioner:
Thanks. I have 844 in R/Y/B and black and white. I don't use them that frequently so I was looking for a way to get more use out of them. I will definitely get some glaze base from MLC next week, however I will give the BLO and mineral spirits a try tomorrow. What is glaze base, anyway? I read in the Knowledge Base that a fellow mixes UTC with paint thinner to make his glaze. I thought that 844 was UTC. The learning curve continues...
From contributor M:
For years pigmented paste colorants were ground in natural resins. At that time common solvents would work in the different types of paste colorants. Then, through chemistry, they developed synthetic alkyds which are used in the grinding process of the coloured pigments and act as the binder. When this happened, it created problems with some of the solvents that were normally used in making up pigmented stains, glazes, etc.
Then the government wanted to reduce the VOCs in the list of solvents, so they started removing or reducing some of the solvents that were always used to create these finishing products. There are companies that do sell pigmented colorants that contain no binder (no synthetic alkyds or resins).
It's all colorant. You add these colorants into your coating, drying oil, etc, which then acts as your binder, making it one colorant for all kinds of finishing mediums. This eliminates having two or three different kinds of paste colorants in your shop.
From contributor D:
Glaze base is just a neutral colored medium and you then add appropriate universal tints to that. The formulas vary a lot, but the base is designed to lengthen or otherwise improve the working quality of the glaze. No, you do not have to always use a glaze base with your UTCs, but in some cases you may need to. I mix 824 UTCs in mineral spirits all the time and have been doing it routinely in lacquer schedules with no problems. Picked up that nice little tip here some years ago.
A solvent/UTC glaze will not give you much time to work with, so this is where a base may help you out, or as contributor M stated, adding a little boiled linseed oil to extend the time that glaze is workable. Sometimes I use a little clear oil stain base to achieve the same purpose. A little goes a long way.
From the original questioner:
Okay... What's the difference between 824 and 844? Probably won't go out and buy any right now, cause I got plenty of 844, but for the next time...
From the original questioner:
By the way, BLO works as a binder for 844 black, just tried it out. I will give it a go with the other colors.
From contributor M:
Most pigmented wood stains will also work as a glaze, depending on the size of the piece you want to glaze. A little boiled linseed oil or tung oil added to the wood stain will turn it into a glaze.
From contributor S:
What's so tough about using a stain/glaze base such as MLC Base 10 or Base 20? Why do experiments using homebrew crap? Why risk a callback/lawsuit for non-compatibility when there is no need to?
824's are used with heavy oil base solvents like mineral spirits and naphtha and can be used with BLO. For decades this was the standard oil based stain solution and worked well with conventional lacquer based systems.
844 are higher end acrylic colorants and are used with less oily solvents and glycol ethers in acrylic binder systems. These more modern stains are much faster drying and compatible with catalyzed systems such as acid cured conversion varnish and 2K acrylic urethane systems. They are ideal for catalyzed finishes whereas straight oil stains of the 824 often aren't. This is what's in the MLC stain and glaze bases and in fact, 844's are what Campbell uses exclusively in their pigmented stain lines. This is sort of a save a buck, spend a thousand situation.
From the original questioner:
I live 120 miles from the MLC or any other distributor, so my glaze base won't be here until Friday. So I have plenty of time to do that home\brew crap before the good stuff gets here.
From contributor M:
That "good stuff" is just another product for you to buy to make the colorants work, because the companies don't want to spend the money to grind their pigments in ester gum. It's cheaper to use synthetic alkyds. That old time glaze that's made up with 3 easy to buy and use products still works as well as it did decades ago, and you control the dry times and it still works with most of the universals, oils, and japans. Plus, you learn how to become a finisher by doing it yourself, which is still the best way to learn.
