Weird: my acrylic paint went all sloshy

[railsquid]

So it's been a whole while (couple of years) since I got my acrylic paints out (the stuff which comes in larger tubes) to paint some landscape, strangely the paint in the tube of green I was planning to use had turned very watery and sloshes about in the tube, which I've never experienced before. No idea how old the tube is, but it's with others of similar age and they are OK.

 

Anyone know why this might have happened, and is there any way of thickening it up again?

[Yugamu Tsuki]

I know the acrylics I use for by buildings I usually shake pretty vigorously before hand since the liquid separates prom the pigment and you get an oily mess. Haven't had an instance yet where with enough time you can't get the paint to mix again. Some pigments don't stay emulsified well with their liquids than others, also happens with oils too.

[railsquid]

Aha, I'll try shaking it then.

[cteno4]

Sadly if acrylics separate for too long they can glop up to where they will never remix well or polymerize well. Before you paint something with paint that has separated badly and you’ve remixed, do a small test and see how well it applies and dries. Also remixed paint may be more prone to gum up airbrushes with not all the smaller pigment particles breaking up. 
 

one thing that helps with mixing is to put a glass or stainless steel ball in the bottle. Really helps mix the paint up well (think rattle spray cans). You can get them at most hobby sources under “mixing balls” in different sizes. Some acrylic paint lines come with one already in the bottle (nice of them as counter to you buying more paint!). The other method is a little paint mixer like one of those coffee milk frothers but with a tiny mixing head. You put the end in the bottle and go at it. Bit of work cleaning the mixer end, mixing balls just stay in the bottle.

 

jeff

[Kamome]

Agreed. I add a Mr. Hobby metal ball (about ¥300 for a bag of 60) to all my Vallejo acrylics as they don't tend to mix well just by shaking after they've been settling for a while. 

 

Strange behaviour of your paint, its usually the opposite that happens. Depending on the brand of paint, if they're old and are made with a largish water content percentage, it may have partly evaporated and encouraged the acrylates in the paint to bond together and you get clumps. If it's sloppy, I wonder if one of the other ingredients has broken down somehow, such as the binding agent.

 

I swear by Vallejo. I've had a good number bought in the UK for about 8 years (sadly when Hobby Zone was closing down) and many are still going as you don't tend to waste any paint. The bottle nozzles are easy to clean and as they produce a wide variety of colours for military modelling, many of the colours suit railways too. Tamiya acrylic is easier to mix for airbrushing but trust me, paint some Vallejo Burnt Umber on your train couplers and tell me it doesn't come to life. It will need clear coating as its doesn't seem to adhere as well as Tamiya unless its brush painted in my experience.

 

Vallejo seem to only be available from Volks in Japan which is always dangerous as I may come home with another HO DD54 or perhaps an EF13 or 0 shinkansen. For paint and general modelling supplies, Volks seems to be the best I've found, in Kyushu anyway. Is it wierd to geek out over paint??

 

 

[railsquid]

I'm not all that knowledgeable about paints, but to avoid any confusion, this is not for airbrushing (at least I assume not, don't even have an airbrush...), it's the stuff which comes in tubes similar to toothpaste tubes as purchased from art supply stores etc.. I squirt some into a paper cup, dilute with water and dab onto the landscape (and clothes, floor and whatever else is in accidental reach) with a paintbrush.

 

I haven't looked at it further, but the strange thing is, it feels like the entire contents has watered itself down, not e.g. separated into constituent parts.

Edited November 16, 2023 by railsquid

[cteno4]

Ah that helps. Sounds like concentrated artist acrylic paint. I kind of doubt once that stuff separates it will go back together. I’d guess you would have to smush it all out and try to mix it thoroughly bit the you could not get it back in the tubes. I doubt it will mis well inside the tube. You could experiment with one tube.

 

i have a feeling he’s dead, Jim.

 

jeff

[MeTheSwede]

Paints will tend to separate over time. Every sort of paint will have a precise mix of ingredients that is different from other paints so their tendency to separate will be different. I guess few manufacturers will take the time to make experiments where paint is stored for many years before they release a new product.

 

I suppose gravity will play a major roll in any separation processes. Nowadays I keep all my vallejo bottles in the same box, so that they will get mixed around whenever I'm looking for a bottle.

[chadbag]

You can try mushing the tube all up in your hands.  Kneading etc.   Don't have experience with this myself.