Warming paint cans.

[BigTallDad]

Since there seems to be some concern regarding the can cooling off, why not use several cola-can foam insulators to maintain the heat?

[Art Anderson]

Since there seems to be some concern regarding the can cooling off, why not use several cola-can foam insulators to maintain the heat?

Releasing the pressure of the propellant in the spray can when spraying is what cools the can off, as opposed to simple heat loss through the steel can.

Art

[BigTallDad]

But the foam rubber will still help maintain the temperature, because of the heat retention it provides.

Are you saying that the foam rubber will not help at all?

Edited July 26, 2015 by BigTallDad

[Art Anderson]

But the foam rubber will still help maintain the temperature, because of the heat retention it provides.

Are you saying that the foam rubber will not help at all?

The foam rubber cup only keeps heat from escaping from the sides and bottom of whatever vessel it's used on.  In the case of propellant pressure being released, that's internal.

Art

[DaveM]

Any time the volume and pressure are changed, the temperature will change too.  The heat is not going out through the sides of the can.  The temperature is dropping in response to the drop in pressure and the change in volume of the gas in the can.  It's the same principle that air conditioners and refrigerators work on.  It's the same law, but in reverse, that explains why compressed air heats up.  No real way around it except to pump air into the can as fast as the gases are released.  (Which brings us right back to an airbrush and compressor)

[AzTom]

Since we are spray cans, I have a question about the Model Masters seeping out as mentioned earlier.  What is it that is actually seeping out?

 It doesn't matter what color the paint is, the seepage is always a dirty clear color. I have had round gobs seep out the size a quarter but it does not seem to hurt the paint any. Still sprays and dries quick. 

[Foxer]

I always went upstairs from my basement workshop to get some hot water in a pan to warm paint cans, but I just got a dehydrator and am considering using it to warm spray cans as it's next to my paint booth and more convenient, not to mention seemingly more efficient at warming.

 

Has anyone used a dehydrator to warm spray cans and are there any dangers to it?

[Pete J.]

A thought just occurred to me about rattle can vs. airbrushes.  One of the biggest knocks on airbrushes(and some claim it as a reason for not using them) is the time it takes to clean them after you are done. I can strip and clean any of my brushes in less that two minutes.  That is far less than the time it takes me to heat a rattle can and then reheat it if it is a long paint session.  For the record I do use rattle cans for quick paint jobs, but I keep the cans I use frequently in a food dehydrator so they are warm when I am ready to use them.  Been doing this for 15 years and never had a can fail or bulge or react adversely in any fashion.  The food dehydrator runs at about 110 F.  There is no open ignition source in the dehydrator so a burst can would be unlikely to light off.  The food dehydrator would also likely to contain most of the paint in the case of a failure. 

Shaken, not stirred.  One of the things that I learned a long time ago is it to store my rattle cans upside down.  There are a couple of reasons for this, especially for long term storage.  The primary reason is the shape of the can.  The reverse dome on the bottom allows the pigments to settle into the small groove around the bottom edge and it is hard for the glass balls inside to get down in that area to agitate the paint into solution.  The balls are also somewhat hindered by the dip tube(the straw leading to the nozzle) which could cause uneven mixing.  With the pigments in the upper dome, they settle in the middle and there is no hindrance in the balls getting to that area to mix them up.  Also, when you store the can right side up, the dip tube in very near the bottom and the pigments will settle around the dip tube and in long term cases in the tube.  This easily causes a clog.  By inverting the can the dip tube remains clear of the "sludge" in the bottom and is more likely to function properly. 

Edited July 28, 2015 by Pete J.

[Foxer]

Thanks for relating your experience with using a dehydrator to heat spray cans, Pete! If you've been doing it for15 years it's a pretty safe bet it works.

[Pete J.]

anks for relating your experience with using a dehydrator to heat spray cans, Pete! If you've been doing it for15 years it's a pretty safe bet it works.

For the record, this is the unit I am using.  It hasn't changed at all except for an occasional color change and the "brand"  It is sold under a lot of names but they all look the same.   This one happens to be a Ronco.  I have chopped up the internal racks over the years to give me more depth and glued some together for convenience.  Works fine and I have never felt like I needed something fancier.

 

[James2]

I simply use a rice sock (Like you would use for a sore neck), heat for 2 minutes in a micro. Wrap around the can and let sit for a few. If you use two rice socks you can alternate while the paint gasses out between coats. which will keep the can warm longer and more consistently.

The best part is no water to deal with while spraying.

If it's to hot to handle it's to hot for the can!

Edited July 28, 2015 by James2

[Mike Kucaba]

I always went upstairs from my basement workshop to get some hot water in a pan to warm paint cans, but I just got a dehydrator and am considering using it to warm spray cans as it's next to my paint booth and more convenient, not to mention seemingly more efficient at warming.

 

Has anyone used a dehydrator to warm spray cans and are there any dangers to it?

I used to do that when I lived in IILAnnoys, Here in AZ (Mesa) My screened in patio serves the same purpose

[Tesla]

My personal choice for warming paint cans is a dehydrator set @ 85 degrees. After 3 or 4 minutes, I remove it and shake it. Then back in for 2 minutes, remove, shake and paint.

This is what I use for shaking aerosol cans: http://mixkwik.com/

It does a great job!!