Im not sure I understand? The high pressure line, is what I have hooked up to the "tank" (where the psi gets measured) and produces only 80 psi.. (does that mean the compressor is bad?)

The capped off line(s) are what I assume the cooling (low pressure) lines, correct or no?

Should the high pressure and cooling lines effect one another? (ie: if I leave the cooling line uncapped, would the high pressure line still build "maximum" psi?)

The questions may seem trivial, but Im not very familiar with refrigeration compressors, if ya hadnt noticed. :)

OK, thanks for the patience and help Rich! I must of damaged it when I was trying to de-solder those copper lines? (I've also been told that since it's so small, it may only be capable of 80psi?) But it does seem like it's leaking internally, since the cooling lines being open prevent it from building more than 20psi.. But for whatever the reason, it's not making enough psi for what I need it to do.. Im going to try the local scrap/recycle yard, in the morning, and see if they may have some compressor motors from folks who bring in old friges and stuff.. Im going to look for a 1/2 hp, hopefully with only 2 "functional" lines!! :D

That makes sense! So I guess any compressor from a refrigeration system should be able to pump 100+psi.. Just seems odd that soldering (or attemting to) could damage it..

Ever seen the insides of one? Wonder if theres some rubber seals or something that I could of melted, tryin to desolder those copper lines? That's all I can think of, as the night before I picked it up I went by and checkout out the freezer and it was cold and had ice trays frozen in it.. Figures I mucked it up myself.. :o

Yea, most of the stories I read about (guys building these things) are using 1/2 HP compressors.. But the guys on those (airbrush) forums dont know the why or the how, just that they built one and it worked.. I've read of them using refrigerator compressor motors and one used a 10,000 BTU compressor from an air conditioner, and aparently it worked nicely as well.. There telling me my 80psi is plenty to airbrush with, for doing detail work and just playing around, but to spray tee-shirts you need between 40-60 "working" psi, so you can get the paint to penetrate the fibers of the shirt or clothing.. So I need to look for a bigger motor.. Im going to check the scrap/recycle yards tomorrow on my way home and see if they have anything.. I'll let ya know if I come across one that fills the need! (and the tank) :D Thanks again Rich!!

The fat thing is the low side filter/dryer. You will have to plug them in to identify which lines are high and low.