recently i get rough surfaces when i paint my models, i have a sparmax ac-100 compressor (tankless), recently the pressure drops around 10 psi gradually when i push the trigger on the airbrush. it has been working in a dusty place so im not sure if its still good to use or not. the question is: can the malfunctioning compressor cause the rough surface problem? by maybe pumping dusty air or other things? i may want to buy a TC 620X if i know that the AC-100 is no good anymore but since its quite pricey i decided to talk to the elders first. thanks in advance.
Don’t know the specifics on your unit, but since you are in a dusty area check the intake for a filter, might be clogged up if there is one. Can also make up a tank out of heavy duty PVC as long as you keep the pressure down to a reasonable limit. That will help on losing pressure and will give a cooling trap as well.
Isn’t the AC100 a diaphragm compressor? Sounds to me that the compressor can’t keep up with the airbrush which could mean a leak some where (like the diaphragm itself or the seals). Really can’t be much help. But if you decide to get a TC620X I can tell you its a great compressor. Have had mine for a couple a years with nary a hiccup. I bought mine from Dixie Art - $299 shiipped (actually it is drop shipped from the SparMax US distributor in NJ). Best price I could find. Here’s a link:
No relation to Dixie Art but have had great service from them. And just had a look at a pic of an AC100. Looks to me that it has a bleed regulator. Is the adjustment at the bottom of the moisture trap adjusted to allow a higher pressure or is it leaking?
While compressors can cause finish problems, so many things can produce rough surfaces that I’d look hard at the other issues first. Number one roughness problem is painting in a dusty or dirty area. Keeping humidity reasonable is another dust/roughness problem.
if you mean the knob at the bottom yes it is always leaking and i use it to adjust the pressure. i sent it for maintenance and the guy wants to charge me 50$ to change the piston and the bearings! i dont think it has anything to do with it, what do you think?
can i add a tank to it? does it solve the problem? do i need to pay for a regulator or maybe the old one already installed on it is usable . i dont have any ideas and paying 300$ for a TC620X is the last thing on my mind, please help.
It’s unclear, was the compressor stored in a dusty place, or your work area is dusty?
If you are spraying in a dusty place, for sure that will trap dust on the painted surface. If you are unable to move to a cleaner area to at least determine if that is the problem and not the compressor, get a spray bottle with water, and moisten the air around your spray booth. I know some, that spray in their garages, will hose down the floor area to help keep dust down.
I don’t know exactly what the problem is, but nothing should be leaking anywhere.
edit: looking up the AC-100, it looks like you do have a regulator and moisture trap. I think I see the knobs at the bottom you are referring to, and there definitely should not be a leak there.
Is there a stem at the bottom of the trap? That is a moisture purge and possible it is stuck open or semi-open?
Your compressor does have a bleed reglator since you adjust pressure by opening the valve. As such, it will run continuously while you’re airbrushing or not. Bleed regulators are not as precise as diaphragm regulators and a significant pressure drop when first depressing the lever on your AB is common BUT it should stabilize within a few seconds - if it doesn’t there’s another problem. Bleed regulators are rather simple devices and it seems to me that yours is working as it should. What happens when you close the valve so no air can come out the regulator? Does the pressure build upwards to 80PSI (spec)? If you then shut the compressor off, is the pressure maintained? If not there is a problem else where. The maintenance people should know what needs fixed but whether to spend $50 is up to you. Note that for $70-$90 you could have a new compressor with better features.There are a number of modelers on the fora who use the following.
The AC-100 doesn’t have auto on/off so adding a tank won’t solve your problem unless you add a proper diaphragm regulator to the tank and an on/off pressure switch. Again, more investment. Sorry I’m not more positive but if the maintenance people say you need a new piston (there’s a valve on the piston which could be the source of your problem) - well they should know.
very well said and thanks a lot. i will buy TC 620 as it seems i dont have any other choices and all the reviews say it lasts forever. the price i can get for it is 240$.
anyway there is also another option. a big chinese compressor with a 10 litre tank which is mainly manufactured for industrial purposes and the price is only 100$. the problem is that it makes a LOT of noise when charging the tank.
actually the place is not THAT dusty. i think the real problem is the bleed valve regulator as Bick explained. the pressure drops too fast and too much.
thanks, actually i do paint my models a bit hasty. sometimes paint the base coat an hour after priming and make the paint a bit thinner than usual, how common does that make a problem?
