Tru-Color Paint Evaporation

[nebrzephyr]

So I have some Tru-Color paint (new, un-opened) purchased several years ago. Evaporation has occurred leaving solids at the bottom of the bottle.

Two questions:

- can these be recovered, and
- what thinner would be used to do that

TIA. Bob

[mpi]

Acetone. Lot cheaper than Tru-color thinner. Some people say they have trouble mixing acetone. I've been doing this for years and never have a problem

[nsc39d8]

I will second the acetone as thinner. I however have not had much luck with recovering the solids, especially if they are dry. If there is some liquid even really thick a slow addition of acetone and
shaking/stirring the mix will help. It is easy to get the recovered paint to thin as well.

[nebrzephyr]

Thanks for the feedback. I question whether I will be able to get these "reconstituted", pretty solid blob on the bottom of the bottle. Maybe if I had a ultrasonic cleaner it would be possible.

I can see why many dealers only sell these stuff as "special order". They don't want to be stuck will a bunch of non saleable product. Tru-Color paint is nice stuff, but I think you need to treat it as "one and done", shoot your project and pitch any remaining paint in the bottle.

I wonder if this stuff would have a longer shelf life is one transferred the paint to a glass bottle.

YMMV. Bob

[Judge Doom]

I've noticed a "paint smell" coming from my TCP plastic bottles (even new ones), the only brand of paint I've had that issue with, so perhaps that contributes to them going bad quicker.

[nsc39d8]

One thing I have noticed is it just the paint straight from the factory. All the Tru-Color paint I have thinned with acetone has held up close to how Floquil would hold.
Then again I find it is only a few colors that have the evaporation problem, can't name them right now.

[edwardsutorik]

I don't see how it can "evaporate" if the bottle cap is sealed properly to the container--how would it get out?. Perhaps, with the design of the cap/bottle, it can't be done.

Ed

[riogrande]

The seal probably isn't 100% is why paints dry out over time, maybe quite a long time. The seal may have cardboard or paper product in it which compresses and very slowly allows liquids to escape in vapor form. Any bottle with headspace in it is going to have some of solvent in vapor phase there. It probably leaks out over a period of years slowly.

Back in my environmental geology days I used to run a gas chromatograph. In order to calibrate it we would order standards from a laboratory company which would contain a liquid of a known concentration of what ever we were testing for, such as BTEX compounds (Benzene, Toluene, Ethyl Benzine and ortho, meta and para Xylenes. We would draw out the vapor in the head space through a septum to inject into the chromatograph to calibrate it a several known concentrations. That way when we took soil vapor samples, the machine has points of reference to tell us if it detected toluene based on travel time to the ionization chamber, and the concentration, in parts per billion or millions.

Paints with volatile organic compounds would probably be more susceptible due to the volatile nature of the solvents, such as toluene, xylenes or acetone. If paint came in a fully encapsulated ampules, such as the kind you have to break open to get the contents out, then probably you wouldn't see evaporation of the aqueous part of the paints, at least until it is opened.

The paint smell is likely indicative of a tiny amount of the solvent escaping the paint bottle; some things can have a detectable small at even very low concentrations.

[edwardsutorik]

I agree that if you can smell it, it's escaping.

Floquil used have a thin piece of clear plastic in their lids (along with the cardboard). I think the seal was made between the plastic and the glass bottle, and the cardboard sort of evened out the pressure on the plastic.

I've been using Testors lately. There's so little in the bottle that it doesn't last very long. Good news, bad news.



Ed

[nebrzephyr]

Dec 31, 2020 9:49:37 GMT -8 edwardsutorik said:

I don't see how it can "evaporate" if the bottle cap is sealed properly to the container--how would it get out?. Perhaps, with the design of the cap/bottle, it can't be done.

Ed

Ed, as I mentioned a couple of the bottles I was referring to were brand new, never opened. Maybe you're right and they need a better cap design.

Bob

[nebrzephyr]

Dec 31, 2020 12:20:25 GMT -8 riogrande said:

The seal probably isn't 100% is why paints dry out over time, maybe quite a long time. The seal may have cardboard or paper product in it which compresses and very slowly allows liquids to escape in vapor form. Any bottle with headspace in it is going to have some of solvent in vapor phase there. It probably leaks out over a period of years slowly.

Jim, I have many old Floquil paints from 40+ years ago, even some partially used, that are as good as new. So I'm not sure what TC paint problem is. Bob