decanting spray paint for airbrush

I have a collection (more than a dozen) of various spray nozzles with tubes. Such as ones that come with WD-40 spray lubricant, Brake Parts Cleaner, etc. etc.

Spray cans have a wide range of nozzles (even if they look the same at a first glace - they are not). Sometimes I am able to remove the front orfice piece from a regular nozzle and I'm able to fit one of my tubes to it. I was even able to find a larger diameter tube to fit the Tamiya Nozzle!

Once you have a nozzle with a tube, then decanting paint into a paintbrush jar is easy.

Warning: when decanted this way, the propellant (propane?) is still mixed with paint so the paint has a tendency to foam up. Just do it slowly and let it gas out for a while. I usually let it gas out for few minutes (warming the airbrush bottle with my hand, while swirling the paint around). Once the bubbles stop coming out of the paint, you can airbrush it. SOmetimes it takes longer to gas out. I put the cover on the bottle (not too tight) and let it sit overnight. If you don't let it gas out, the airbrush will spray very strangely!

Also, don't do this on a humid day. Gassing out cools the paint, so you might get some condensation into the paint. And water and enamels don't mix!

When decanting, don't fully depress the nozzle - go easy - no full blasts.

Once you get a hang of this, you'll love the results! But on your first decanting tries, wear some old clothes and be outside (in case of a spill).

Another method you could try is to spray out all the propellant by holding the can upside down while holding the nozzle open. Once there is no more gas pressure inisde the can, wait a while and then do it again. Like I said, the propellant is dissolved in paint. YOu might have to do this multiple times.

Once there is no more pressure (only paint is left in the can), you can poke 2 holes in the can and drain the paint. Make sure to shake the can well before poking holes (to get the paint mixed up).

Peteski

snipped-for-privacy@my-deja.com (Peter W.)

Once propellent is gone, pop it with a can opener in one swift move. Puts a big hole in there quick and equalizes redisual pressure immediatly.

Having read the steps one needs to take to do this I'm wondering if it's really worth the effort. What are the results like compared to properly thinned paint? TIA John

It works fine with Boyds and Testors, in my experience.

Mark Schynert

I recall Al S. had a really painless technique for this which my soggy little brain has forgotten. Al, you on? tia

The Keeper (of too much crap!)

Correct, the paint is perfect consistency for airbrushing. Yes, this works for all aeorsols ( that is why I have a large collection of nozzles). But some paints aren't plastic compatible.

Also to answer another poster's question: Yes this is worth the effort. Some paints (like Tamyia enamels) are only available in aerosol cans. And doing this allows you for much greater control of spray.

Remember, when you mix your own paint from brush ready paint bottles you have to measure and thin paints yourself. My way you just squirt it from spray can to airbrush bottle and it is ready to go!

I also prefer to only decanter as much as I need and keep the rest of the paint in the original can. That way I don't have to worry about it drying up. I have cans over 15 years old which still have usable paint in them.

My lengthy description sounded sort of complicated, but that is because I tried to cover all the bases. In real life it is easy, clean and painless.

Peteski

I got awesome results with Krylon, but my last can didn't yield the same hard, smooth, high gloss finish I had gotten previously. IIRC I got over 2 large baby food jars full of paint from a large Krylon can but only half of one from one of their small touch up cans. I think the formulation is different too, the small cans being softer like Testors.

D_C,

throughout my modeling ventures I have been able to actually collect enough nozzles which already have the orfice removed and a tube inserted (like the complete WD40 nozzle). Various spray can manufacturers use slightly different nozzles. The stem which plugs into the can can be various diameters or configuations. Sometimes I do as you say - remove the orfice and I am usually (but not always) able to find a tube which will fit.

When I decanter the paint, I never fully press the nozzle wide open. I just barely open it to let the paint out slowly. Otherwise, you'll have a mess on your hands.

I never tried to spray directly into the opening on the airbrush bottle cap. I suppose it might work - I'm not sure if the vent will allow the propellant to exit quickly enough. Remember, the paint bubbles and foams as it is decantered.

Using any kind of adhesive tape might not be a good idea as most solvent based paints soften or dissolve the tape's adhesive. Again, you'll end up with a gooey mess...

I haven't actually measured the amount of paint in a 3oz. can. I usually decanter as much as I need for a project and the original can is a perfect storage container... So, I can't answer that.

I would guess that about 1/3 of the can is the propellant. Again, as you decanter, the paint foams up and expands - you need to do this slowly and have container which will not overflow. Normally the regular size airbrush jar (1oz. ?) is enough if you are careful.

Also if you are plamming on only using the spray can for decantering, you can release most of the propellant by spraying it upside down. Just leave enough propellant to be able to decanter the paint (under lower pressure). But since some of the propellant is dissolved in the paint, even though you think you released most of it, next time you use the can, the pressure has built up again.

HTH, Peteski

Turn the can upside down, spray until you get the air out. Repeat till there's no air; shake paint real good open the can with a can opener or saw or whatever and decant.

Some of the valves are "side tilt" types. You could use flexible vinyl tubing on these. Aquarium/pet stores carry some sizes. You may have to look into industrial hose for other sizes. hth

The Keeper (of too much crap!)

Duh? What's a mason jar?

I'm thinking decanting the amount of paint you need and leaving the rest in the can is probably the way to go. It's light proof and ya got the shaker ball going for you.

If you use a big container for storage you expose the paint to a lot of air and it'll go bad on you sooner. Paasche, Badger, etc. make 2 and 3 oz. bottles for just such an occassion and they usually come in the complete kit. Never had an occassion to use mine. Hmmm, where's that Bv-222? Cheers,

The Keeper (of too much crap!)

Keeper - I have a couple of Metallizer spray cans that I bought from MJ Designs when they went under some years ago. Most of the paints I bought that day were okay, but a bunch of the Metallizers didn't work; couldn't get the paint out. I thought that the tips were clogged, but after putting new clean tips on, they didn't work either. I figured that the feed hose inside was clogged, so I opened up one stainless steel (VERY CAREFULLY) and poured out the contents into a small (6oz.) glass jar with a metal lid. I've been using it for touch-ups with a brush ever since with good results. I think now (or soon) I'll try to run some through my airbrush. Also, I think its time to open up the rest of the clogged cans as well.

-- John The history of things that didn't happen has never been written. . - - - Henry Kissinger

Yup, opening a pressurized can involves much trepidation. A vise helps. and old clothes. 8^)

I've got a can from the sixties (car touch up paint) I'm gonna open someday when I'm bored. Cheers,

The Keeper (of too much crap!)