I had a can of Rustoleum Rusty Metal Primer (which I LOVE, BTW) that was mostly empty and had been sitting for some time.
Not surprisingly, it wouldn't spray. The usual fixes (ream out the nozzle, soak it in thinner/acetone) didn't work, so I thought I'd try something read on the InnerWebz. Hey, they can't put it on the web if it doesn't work, right?
So I drilled a VERY small hole in the top to let the pressure off. That part worked much better than I feared, pressure bled off, no paint squirting all over the place.
Then I drilled a larger (about 3/16) hole to pour the paint into a container so I could brush it onto the project. I intended to spray some in a container and apply it with a brush anyway.
This is where the weirdness started. When I first tipped the can to pour it out, it actually came out under pressure. Not MUCH pressure, but enough to make a small mess. I did manage to get most of it out okay.
A minute or so later, I decided to make sure the can was empty and a bit more came out.
When it hit the paint in the container, it foamed up bigtime and overflowed the container. Exactly like pouring a Coke too fast over ice and the carbonation makes it foam over the top of the glass.
As an experiment, I stirred the container with the paint in it and again with the foam. The longer I stirred, the less it foamed until it seemed inert.
So I painted what I set out to paint, lightly capped the container (allowing for more outgassing or whatever was causing the foaming) and wandered off to do something else.
A couple of hours later, I decide to do a little more painting and the paint has separated so I cap it and shake it to remix.
HORRIBLE idea, Genius Boy. MASSIVE pressure buildup, paint all over hell's half acre and much of me.
So my question is...What the hell? Where is this pressure/foaming coming from? The only thing I can guess is residual propellant mixed in with the paint that activates with shaking/stirring.
Not surprisingly, it wouldn't spray. The usual fixes (ream out the nozzle, soak it in thinner/acetone) didn't work, so I thought I'd try something read on the InnerWebz. Hey, they can't put it on the web if it doesn't work, right?
So I drilled a VERY small hole in the top to let the pressure off. That part worked much better than I feared, pressure bled off, no paint squirting all over the place.
Then I drilled a larger (about 3/16) hole to pour the paint into a container so I could brush it onto the project. I intended to spray some in a container and apply it with a brush anyway.
This is where the weirdness started. When I first tipped the can to pour it out, it actually came out under pressure. Not MUCH pressure, but enough to make a small mess. I did manage to get most of it out okay.
A minute or so later, I decided to make sure the can was empty and a bit more came out.
When it hit the paint in the container, it foamed up bigtime and overflowed the container. Exactly like pouring a Coke too fast over ice and the carbonation makes it foam over the top of the glass.
As an experiment, I stirred the container with the paint in it and again with the foam. The longer I stirred, the less it foamed until it seemed inert.
So I painted what I set out to paint, lightly capped the container (allowing for more outgassing or whatever was causing the foaming) and wandered off to do something else.
A couple of hours later, I decide to do a little more painting and the paint has separated so I cap it and shake it to remix.
HORRIBLE idea, Genius Boy. MASSIVE pressure buildup, paint all over hell's half acre and much of me.
So my question is...What the hell? Where is this pressure/foaming coming from? The only thing I can guess is residual propellant mixed in with the paint that activates with shaking/stirring.
