In a message dated 1/21/2007 12:07:31 PM Central Standard Time,
> We used to have this problem all the time at work with rattle cans of Zinc
> Chromate primer. Does it have something to do with zinc? We put it down to
> students not inverting the can and spraying to clean the nozzle after use.
> Maybe we unfairly accused them?
I have no experience with zinc bearing products. It's possible that the zinc
creates its own problems. Paints have three main components: Pigment, binder
and vehicle. The Pigment is the color, the binder is what keeps it in place
and seals the surface and the vehicle is what keeps it all liquid until it is
applied when the vehicle is dissipated (usually evaporates). Spray paints
contain a fourth component, propellant. The main problem is the binder setting
up in the nozzle. Flushing the nozzle with propellant (inverting the can) may
not get all the binder out and the nozzle becomes clogged. But I know nothing
about zinc. Is the zinc supplied as part of a compound or is it just a micro
fine metallic zinc? If it is the latter then perhaps oversized particles
don't clear the nozzle.
> Dave, I have a spray can of AerKroil that is out of propellant but has
> plenty juice left. I was thinking about putting it in a large container in a
> well ventilated area and then shooting it with a .22 from a little distance
> away. Would that work?
If the propellant is gone then there is little risk of explosion due to
propellant. The oil itself is flammable but less so than the propane. But in
event I would think that unless you put the can on the fence out at the farm
and do a little target practice I would think that using fire arms on a
flammable substance is not a good idea.
If there is no pressure left just poke a hole in it and shake out the
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