Hot Compressor

Anthonyb wrote:

Just had an "aha" moment.  The DA400R has a 3 way switch, and the II setting runs it without the auto-shutoff feature and the I switch runs it with the auto-shutoff.  Man they really need to include better instructions, as I was gettting ready to send it back with the complaint of the auto shutoff not working!  So my next 40 minute session should run a lot cooler now that I know that!

I have the older DA400 model which does not have the "always on" option. It has only an 2-way on-off switch and the "auto shut-off" is always working. The compressor runs when the airbrush is spraying and turn itself off when I stop spraying. The compressor gets warm after long AB session, but never hot to the touch.

One thing I don't like about the DA400 is the on-off setting of 70 and 93 psi. I believe the comprssor will run even cooler if they can be lowered to something like 40-60 psi. I added a small one-gallon airtank to the DA400 setup. I expect the compressor to have longer off cycle. But I am having problem with leakage with the check valve. It did not work the way I expect. (The tank leaks slowly and kicks on the compressor after 2-3 minutes even when I am not spraying.) 

The original Paasche DA400 is made by a manufacturer in Taiwan. I understand that they switched sources to China for the newer DA400. Other than the 3-way switch, I would expect little difference in the design and features of the compressor. It is always a good idea to check for leaks around the compressor when you first receive it. The DA400 has an extra link between the two cylinders and more potential to lead because of its high operating pressure.

It is good to hear that your problem is resolved.

When I first started working around aircompressors, I learned they get got hot - sometimes very hot!.  Don't worry about it, it's normal.  It's caused by a little known (at least to most people) phenomonon called Latent Heat of Vaporization - in other words, as a gas is compressed, heat is released (the greater the pressure, the higher the heat) and when a gas under pressure is released, cold is generated (the higher the pressure and/or the smaller the hole - the greater the amount of cold).  I've seen gas pressure lines literally freeze up at the point where the gas is coming out.  Don't worry about the heat, it's natural, just don't go touching the head of your compressor when it's working (or the line from the compressor to the air tank if that's the particular type of set up you have - you can get some really great blisters that way).

Anthonyb wrote:

I have the compressor paired with a Passche H and was under the impression that it should be run around 25 PSI. The instructions that came with the brush say 20-30 PSI for medium consistency fluids and 30 PSI or more for heavier fluids (Acrylics, reduced laquers, etc.) So that's sort of where I got the 25 from.

I have a Paasche H as well, and I have read all the same sorts of things that you have about it needing all that air pressure.  However, in actual use, I find that the thing sprays quite well when siphoning from a color cup at 15 PSI.  Experiment and see what works. 

From you further description of the heat, it doesn't sound as though your compressor is doing much different from what mine does.

Andy

I have the compressor paired with a Passche H and was under the impression that it should be run around 25 PSI. The instructions that came with the brush say 20-30 PSI for medium consistency fluids and 30 PSI or more for heavier fluids (Acrylics, reduced laquers, etc.) So that's sort of where I got the 25 from.

It is an air cooled motor of sorts. But why are you using so much pressure? I too used to believe it ain't flowin unless its blowin. Back'er down to about 18 psi. Make sure you keep your compressor clean, that will help it disapate heat more efficiently, won't hurt to have a fan blowing across it either. Check the inlet filter too!

 

Just had an "aha" moment.  The DA400R has a 3 way switch, and the II setting runs it without the auto-shutoff feature and the I switch runs it with the auto-shutoff.  Man they really need to include better instructions, as I was gettting ready to send it back with the complaint of the auto shutoff not working!  So my next 40 minute session should run a lot cooler now that I know that!   

It has an auto shut off, which I can hear a "click" from inside the compressor shutting off the generation of air, however, the motor does run while it is "shut-off".  At least I assume that's how it works, so please correct me if I am wrong, as you know what they say about assumptions... 

40 minutes is a pretty long time to use the compressor for. Does it have an auto shut off for the times when you aren't actually spraying? When I ran a "little" compressor like that, I used a surge protected extension that had an on/off switch and used it as a foot switch.

Small compressors are oil-less and heat is obviously their biggest enemy. Keeping it cool(er) is in your best interest.

I can hold both of my hands flat on either side of it for about five to ten seconds before it gets too hot and I have to pull my hands away.  Thanks for the response that helps alleviate my concern as I just bought this thing and would be very upset if I ruined it in the first week of use. 

After 40 minutes of use, I would expect your compressor to get fairly hot.  I have a Badger 180-1 which I think is a similar type to your Paasche, and after extended use gets pretty hot.  You didn't really quantify how hot the thing is getting, but unless it is blistering your hand if you touch it or seeming as though it is going to catch something on fire, it's probably just normal operation.

Andy