Decanting spray paint

[Monty]

While it may seem to be a variation on a theme, I like this idea better than, say, decanting using a WD-40 straw.  

Start around the 18:50 mark.

 

[NOBLNG]

Nice idea. It works for the Tamiya cans anyways.?

[Miatatom]

Again, why didn't I think of that.

[peteski]

I have been using the straw-in-the-nozzle method of  decanting paint for years. In fact that is the only method I use (I never puncture cans).

This is my stash of nozzles and straws.  I have accumulated it over the years. As I throw away empty cans (including household sprays) I usually keep the nozzles.  That gives me several sizes and types of nozzles. They will fit a wide variety of spray valves.  For Tamiya nozzles, I have 2 versions shown in the above photo:  For one of them I drilled a small hole in the blue orifice plug to  press fit a small clear tube, while for the other one, I removed the blue orifice plug and found a larger tube which snugly fits into the opening.

The only problem with this is that when the paint comes out of the tube, the propellant gas dissolved in the paint expands back into gas.  That causes foaming, and also cools down the liquid.  Since I know it will foam up, I decant the paint into a larger container, so that is not a problem.  But the cooling effect will cause moisture in the ambient air to condense as water on the container during humid summer months. Fortunately this is mostly on the outside of the container (as the inside is mostly filled with the expanded  dry propellant gas).

As with other decanting methods, not all the propellant dissolved in the pain escapes right away (especially if the decanted liquid is really cool). So, I leave the lid of the decanted paint jar paint not fully tight, so the gas can escape.  After about a day in that state, the lid can be tightened, but even then if I don't use the paint right away, when I shake the jar to mix the paint after few months, some pressure still builds up, so I open the sealed jar carefully, not to have the paint make a mess.

You will also notice a pipette in my stash.  By luck I found a  nylon (not glass) pipette where its tip can snugly fit into Tamiya nozzle's valve stem opening, and for the nozzles with a stem, it snugly slides onto the nozzle's stem. It is perfect for cleaning out the nozzles.  I pour some lacquer thinner into a small container (a shot glass) then install the pipette onto the  nozzle. and put the end of the decanting tube into the lacquer thinner.  Then I repeatedly pump the pipette's bulb to flush the remaining fresh paint leftover from the decanting nozzle./tube.  That way I have the setup perfectly clean ready for next decanting.

Edited May 22, 2023 by peteski

[NOBLNG]

I bought a bunch of large (3/8”) plastic straws at the Dollar store. I cut them in half at an angle and just aim the spray into the uncut end. The paint drips into my Paasche paint jar and most of the propellant escapes upwards from the cut end to be sucked out by the exhaust fan in my booth. I have to hold the straw with pliers since it gets very cold and just toss it when finished…zero cleanup required.? If I only need a little bit of paint, I’ll spray it into a plastic shot glass and use a pipette to transfer it to the airbrush cup.

[ctruss53]

I tried decanting once.  I just taped a regular drinking straw to the spray can nozzle.

Cut a notch in the straw to it has a "flap" that rests on top of the nozzle and then pile on the masking tape to seal it as best as you can. Then spray.

I only did it once because I don't feel it is worth the effort.  I just buy bottles and thin as needed.

[BDSchindler]

13 hours ago, ctruss53 said:

I tried decanting once.  I just taped a regular drinking straw to the spray can nozzle.

Cut a notch in the straw to it has a "flap" that rests on top of the nozzle and then pile on the masking tape to seal it as best as you can. Then spray.

I only did it once because I don't feel it is worth the effort.  I just buy bottles and thin as needed.

I do this also but once decanted, allow it to sit overnight so the frozen part from the decanting process dissipates.

[Dpate]

Cool method, but I’ll stick with straws. Just think if that pipette “pops” off lol. Straw method with little tape at the end, and you’re good to go.