decanting spray paint

[Paul Payne]

I have a can of spray paint which has lost pressure. Is there a way to get the paint out for use in an airbrush?

[NOBLNG]

Let the can settle for a day then poke a very tiny hole close to the top of the can to let any remaining pressure out. Once all the pressure is gone, you can poke a larger hole to pour out the paint. You might want to cover the hole with a rag and shake it up before pouring it out. Be careful removing the rag as there may still be propellant absorbed in the paint. Alternately, you could cut the entire top off after the pressure is gone and stir the paint.

https://www.modelcarsmag.com/forums/topic/138715-how-to-remove-paint-from-spray-cans-when-nozzle-fails/

Edited May 23, 2024 by NOBLNG

[Dave G.]

I decant partial cans of Mr Surfacer and also certain colors so as not to empty the entire can. So I just put the nozzle over the edge of an empty jar. Cover with a paper towel and spray what I need into the jar. I don't fully depress the nozzle though, that will make a mess. Wear rubber gloves as invariable some small amounts of over spray escapes. It's a bit slow but I do get just what I need. Expect to possibly need a little added thinner for airbrushing and depending on the airbrush tip size.

[NOBLNG]

That doesn’t work if there is no pressure.

[RancheroSteve]

I've decanted paint from many cans and in my experience, it's rare that a can completely loses pressure - it's more likely that the tip or tube inside is clogged. Keep in mind that the propellant is actually dissolved in the paint, which is half the reason for shaking a spray can before painting. 

Just use caution if you decide to poke a hole in a spray can.

[Paul Payne]

Guys, thanks for the info. When I try to spray, there is only a light dribble of paint. If I try the hole method, I will shake the can thoroughly. Can anything be used to probe the exit and actuate the valve?

[peteski]

Easy way to check if the can is pressurized is to squeeze it.  It is made from thin metal and if it still has full pressure it will be hard to squeeze, but if the gas is gone (or almost gone), you will be able to dent the can with your fingers (and it will not spring back).  That also tells you whether the paint is not coming out due to lack of pressure or due to clogged valve/nozzle.

[Dave G.]

3 hours ago, NOBLNG said:

That doesn’t work if there is no pressure.

Hmmm, I should have read the OP closer.

[Dave G.]

1 hour ago, Paul Payne said:

Guys, thanks for the info. When I try to spray, there is only a light dribble of paint. If I try the hole method, I will shake the can thoroughly. Can anything be used to probe the exit and actuate the valve?

In my experience if the tube is clogged, it stays clogged. If it's the nozzle you can soak it in lacquer thinner and that generally will clear it. Or change the nozzle to one from a working can of the same brand paint.

That said, even a full can of paint has head room at the top, they aren't 100% filled with liquid. So if you set a can down for a few minutes the paint will settle and you can poke your hole near the top of the can. You won't get soaked in paint. Once the gas escapes, flip the can to drain and poke a vent hole near the bottom, which is now facing up, to drain more quickly. I've seen videos where people use a small number drill rather than poke a hole .

[Bill Eh?]

First, you may want to try removing the plastic nozzle from the can and soaking it an appropriate thinner overnight. This may remove a clog and allow the paint to spray again.

[peteski]

22 hours ago, Dave G. said:

That said, even a full can of paint has head room at the top, they aren't 100% filled with liquid. So if you set a can down for a few minutes the paint will settle and you can poke your hole near the top of the can. You won't get soaked in paint.

I would be *VERY* cautious doing that.  Yes, the can is not full, but at that point most of the propellant gas (usually propane) is still in a liquid state, dissolved in the paint. The already gaseous propane under pressure in the can keeps the rest the gas dissolved. Rapid depressurization of the gas will cause the  paint/propane mixture to start boiling and it will start spraying out of the vent hole.  I would never attempt this process.

 

[Rich Chernosky]

Paul....I decant a lot of spray cans and there is a trick to it. I also collect a lot of the "empties" from fellow modelers because there can be as much as 1/3 of an  ounce left that won't spray out because the tube doesn't go all the way to the bottom of the can.  Most of my friends don't airbrush so I have a huge supply.  Here is the trick. Lay the can on its side, don't shake it as this only increases the pressure. Fold a paper towel over several times then take a sharp awl and go right through the towel into the can slightly. If there is any residual pressure you can slowly release it while squeezing the paper towel  around the awl. This prevents you from getting sprayed. Most empty cans have little or no pressure. Once done take the awl and poke it through at the bottom at an angle and then backward to split the metal. Be careful pouring as it is just like soda and will bubble up over your container. Stirring it will do the same thing.  Adding thinner will help release some of the propellant but it is still best left for it to  sit awhile and fizz out. Don't cover your container either or you might find the top stuck to the ceiling. You will have to thin it anyway to airbrush it by the way.   I have done half full or less cans but the more paint in the can the more pressure and the more careful you have to be.  If your can has a lot of paint in it I would definetly go outside.