Brown paint separating

[Antonio Vasquez]

 I am using a wet pallet to put my pants in while I paint.  I am noticing that every time I paid with my brown Vallejo paint it starts to separate and gets a yellow oily substance on top.  This never happens with the black paint or the black primer that I use. Has anybody else experienced this ,or am I doing something wrong?

[mtaylor]

Does it separate if you don't use a wet pallet?  Try putting it on some wax paper instead.

[vossiewulf]

You're basically running a mass spectroscopy test of the paints with that "palette" arrangement. I'd be more surprised at an acrylic hobby paint that didn't separate. That said, I've seen Vallejo paints act weird with any solvent other than their "high compatibility" solvent, that only really works with their paints. 

[keelhauled]

I'm not really familiar with Vallejo, but I've worked professionally on ink and paint formulations as a chemist.  Vossiewulf's correct, although it isn't actually mass spectroscopy the thought is correct.  It's actually chromatography - a chemist technique for separating out chemicals and was used early in the 20th century by forensic chemists to separate out inks into their individual dye components using essentially a solvent wicking up a sheet of paper.   Then using the results to identify the ink/pen.

 

It sounds like the paper towel and solvent is actually acting to separate the paint into its components.  There is numerous ways to make a brown hue.  One is by mixing red and green (or blue and yellow to make the green or adjust the color brown) pigments or dyes.  I agree with Mark about the wax paper, it should help.  There are drying retarders that can be used to slow acrylic paints.  However, acrylic is just fast drying, especially if it is being diluted by water.  I don't know what you are painting, but if you need a slow drying paint, oils are an excellent option.  Just never use turps to dilute the oil, use one of the oils.  Diluting with terps will actually separate out the pigments from the oil and can cause chalking and other issues.

 

Best, 

marc

[vossy]

Essentially black is a primary colour. Brown is a made up colour of 2 or more primary colours and thus will separate out when diluted.

 

Cheers

 

Chris

 

[vossiewulf]

7 hours ago, keelhauled said:

I'm not really familiar with Vallejo, but I've worked professionally on ink and paint formulations as a chemist.  Vossiewulf's correct, although it isn't actually mass spectroscopy the thought is correct.  It's actually chromatography

Apparently I am not a scientician.

[Antonio Vasquez]

 It was parchment paper that I was using I guess I’ll get wax paper try and see if it doesn’t separate as much .Thank you for the input

[Jaager]

If waxed paper does not work - I have found soy sauce flat-ish  micro dipping bowels in an Asian food market in various sizes that may work.  Not expensive. Works if your community has an East Asian population that is large enough to support a market.

Edited January 10, 2019 by Jaager

[jim Landis]

I got a sleeve of plastic 25 ml sauce tubs at a local restaurant supply store for this application, styrofoam plates also work well as palates for water based paints.

[keelhauled]

Hi Vossy, 

you can actually get primaries and secondaries as single pigments as well. black (black often has blue toner added to keep the carbon black from being a little on the red (brown) side.  For example, you can get several single pigment brown pigments made from different oxidation states of Iron as a single pigment.  These range from almost red through a deep brown (Can you tell I love pigments and dyes?)😊

 

Antonio, I'm sure that the wax and plastic versions will help.

best!!

Marc