When spray bombs don't spray??

[Joetrain59]

I'm sure this has been covered before, but I need a quick refresher. Is there anyway to get them to dispense paint again? Without spitting/splattering. Most are Model Master, testors, and some Floquil. Some not even used yet. Have to check them all outside tomorrow, to see what goes to new house, or what I have to dispose of in an environtmentally responsible way.
 Thanks,
 Joe D

[mmagliaro]

With all spray paints in general, when they start doing that, I try pulling the spray button right out of the top of the can and letting it soak in a jar of mineral spirits for a few hours.
After you soak it for a while, you may have to work up inside the little stem with a straight pin, and even gently poke the microscopic hole in the front where the paint comes out, and then soak it some more.

That's all I've got.

[Joetrain59]

Max, I have soaked the nozzles before, usually 91% alc. or Bestine. Do have spirits in garage. I'll see how I do.
 Thanks,
 Joe D

[peteski]

Are those N or Z scale cans?  They must be tiny! 

The way I see it is that either the valve or nozzle were clogged up (you didn't clear them well enough after last spraying session), or the propellant escaped so there is no pressure inside the can.  Actually, another reason might be that the pigment settled on the bottom of the can is clogging the tube which picks up the paint from the bottom.   Did you shake the bejesus out of them before trying to spray?

Try to squeeze the side of the cans. You can tell if they are pressurized (hard to make the metal wall give) or does the wall give easily (no pressure inside)?

If they are still pressurized then try to replace the nozzle with one you know not to be clogged.  If it still doesn't spray then the valve is most likely clogged up or blocked with some dried up paint. Some people stick stuff in the valve trying to unclogged but I would not attempt that (you might end up with paint all over yourself).  Toss them (but not in the garbage). Find a proper way to dispose of them.

[nkalanaga]

I never did have any luck with most Floquil cans.  About the only ones that worked for me were Grimy Black, Big Sky Blue, and the gloss clear coat.  The others usually failed after one use, if the worked at all, and cleaning didn't help.

On the other hand, Model Master, and Pactra, usually worked fine.  I didn't use enough Testors to have an opinion on them.

Fortunately, the only colors I absolutely HAD to have from Floquil were Big Sky Blue and Grimy Black, so it wasn't to big an issue.

[mmagliaro]

Try Tamiya.
They don't make "railroad" colors, but they make useful colors.  (Their TS-6 matte black is great for steam locos).
That stuff sprays clean and is atomized very finely.  I never had trouble with their cans clogging.

[grove den]

I use compressed air( can)...just take/pull the spray button of and use the compressed air to blow out the residu of the paint in the button...easiest way is to blow  the air keeping/holding the spray button upside down... . Of course right after you used the spraypaint/can!

Jos

[StewRRFan]

I've had some luck in placing them in some warm water.

[rschaffter]

I clean them with spray Gumout carb cleaner, which is basically lacquer thinner...

[Joetrain59]

I am diligent about spraying tips clean after using. Have had some Floquil spray bomb duds right from the LHS.
 I'll see today what cans spray, and what cans don't. Then try ideas from this thread.
 Thanks,
 Joe D

[Maletrain]

I see that all of my ideas have aleady been posted.  So, just want to add the thought that I would not try to put any pin or other object into the small nozzle orifice on any can I want to use for spraying models.  That seems likely to mess-up the spray pattern and cause droplets.  I would try soaking the nozzle and then using a can of compressed air to blow backward through the nozzle, but not while wearing good clothes.

[C855B]

... a can of compressed air to blow backward through the nozzle, but not while wearing good clothes.

Emphasis added, quoted for truth.

Related, I had a car many moons ago that required bleeding the brakes using external pressure. I rigged up an air line to the fluid reservoir. You can guess the rest. On the plus side, it was a good demonstration of how effective brake fluid is as a paint stripper.

[mmagliaro]

I clean them with spray Gumout carb cleaner, which is basically lacquer thinner...

This made me curious, so I hunted down the MSDS for Gumout online.  The ingredients seem to vary quite a bit depending on *which* Gumout you use and how old your can is.

But for the basic spray carb and choke cleaner, it doesn't appear to be lacquer thinner, which is much more Toluene, MEK, alcohol, and only about 5% acetone.

Gumout Jet Spray Carb and Choke Cleaner (2015)
It is mostly acetone with a little toluene in it (about 60%-100% acetone, 5-10% toluene... they won't divulge how much of each is in there as it is a trade secret).

Gumout Jet Spray Carb and Choke Cleaner (2001):
Naptha (30-50%)
"Hydrotreated Light distillate" ???   10-30%
MEK 1-7%
Alcohol  1-7%
Propane (10-25%)

Pretty big changes in the formula over the years!

[havingfuntoo]

I bet Gumout have stopped using MEK in their formulation.

[Joetrain59]

So, out of 28 spray cans, 3 were virtually empty, 4 don't dispense at all, (brand new can in that group), 1 sprays a stream, and the last sprays all over itself and my gloved hand. Will try soaking tips tonight. Not sure if I have mineral spirits. Acetone? Denatured alc.? Brake fluid? Brake cleaner?
 Joe D