UTC Colorant Compatibility

UTC 824 and UTC 844 colorants are different compounds, and are compatible with different finish formulas. Choose appropriately to avoid mixing problems. March 28, 2008

Question
I'm blending a very light white in SW white CV. Per gallon, I used about .08 ounces of yellow oxide 844, and 14 drops of UTC lamp black. Got the color I needed, but to my dismay I'm getting black splatter randomly in the finish. Fortunately I'm planning a second coat, but why isn't the UTC totally dissolving?

The first 10 drops went directly in the paint while stirring, and the rest I mixed in butyl acetate first just to see how it would dissolve. Should I have pre-dissolved all the black? Or will it still coagulate and splatter?

Now I am up against a time deadline and don't know if I should buy some 844 lamp black or if I pre-dissolved all the UTC, would I still have this problem? At $40 per gallon I don't want to be throwing it away. What has anyone experienced with Huls UTC versus 844 from SW in CV? Do the 844's dissolve better in CV?

Forum Responses
(Finishing Forum)
From contributor D:
These are both made by Degussa (at one time HULS owned these colorants, but they have gone through at least five changes of ownership that I'm aware of). The UTC 824 series are long oil alkyds suitable for making stains and tinting linseed oil based paints. 844ís are acrylics and much more versatile and useable with urea formaldehydes such as conversion varnish. Why are you having an existential moment over this? Buy a quart of 844 LB and be done with it.



From contributor J:
I had a problem same as the one you described. The only answer I ever received from anyone was that I failed to properly mix the chemicals and that I should buy an air powered mixer. I scrapped the pail I was working on, and started over with all new chemicals. I had no further problems, ever.


From the original questioner:

My existential moment has passed. I came to that conclusion, but wanted confirmation since it's a half day trip to town to the one supplier who carries 844 and I knew it would throw me back time-wise. I actually hoped someone would tell me a trick like microwave the colorant or something clever (kidding).

I did get the 844 lamp black and used exactly 6 drops for my gallon formula and have sprayed half the kitchen with no more colorant splatter. The UTC just isn't compatible with the CV. You would think using such a small amount, it would dissolve, but no dice. Lesson learned, and thanks.



From contributor B:
The UTC's aren't compatible, as you said, and that's the reason why most of your neighborhood paint stores can't tint up your lacquers even if they carried lacquers. They don't have the proper tints, only for your latexes and alkyd based paints.


From contributor W:
Just for information purposes only. We package small 4 oz bottles of the Degussa 844 and 896 colorants for a guitar supply distributor. The small amounts come in handy when you don't need a whole quart and they can be mail ordered. They have a limited palette of 7 colors, but that covers most situations. They sell them as Colortone Liquid Pigments for Lacquer (844) or Waterbased Lacquer (896).

P.S. Contributor D, it is now called Evonik Degussa Corporation, and will probably be just Evonik Industries eventually.



From contributor C:
There is only 1 true U.niversal C.olorant S.ystem that works for all types of coatings - that is one you make yourself from dry colorant powders that can be incorporated into whatever coating you desire - much as touch up powders for repairing wood/metal/plastic. Yes, I'm fully aware of needing a mil to do so - but small mils are cheap compared to what you pay others for a finished product over the long run - especially when it comes to 844/896/others. In a few years you won't have regretted the investment!