Air supply line advice

[70 Challenger Lover]

I picked up a shiny new commercial grade sandblaster and there are different nozzles depending on how much air volume the compressor supplies. My compressor supplies about 16 cfm and I can match the nozzle to the supply but one thing I am unsure about is whether my supply line of 3/8" is simply too small to move this volume of air. Doesn't seem like this topic should be complicated but when I do research on the Internet, there are tons of overly technical explanations of system recommendations and requirements.

Am I correct in assuming that a 1/2" hose will be more suitable to use for the sandblaster than a standard 3/8 hose? I can replumb the outlet at the compressor so there are no bottlenecks anywhere.

I already have a large blasting cabinet and for years I have been using a 3/8" supply line to feed it. It works fine but every now and then I need to let the compressor catch its breath. Lately I've been thinking that it might also benefit from a 1/2" supply line.

I am using a water separator but I'd appreciate advice on how to set this all up properly.

[YellowThumper]

Well, if you have to wait for the compressor to catch up then a larger line will not be a benefit.
You are already exceeding its ability to feed it continuously.

However...
A larger line will allow the are in it to move slower. This slower movement of air (more resident time) in line will allow it to cool down more. Thus releasing more of its moisture.
The larger and/or longer the line also will increase the "tank" size.
Separator should be located a fair distance from compressor to allow the air time to release the moisture being carried by it. I am sure there is a formula for this but I am not schooled on it.
Another thing I have learned from past while working in a heavily air dependent shop was to have all the drops pulled from the top of the main feed line. Have at least one drop from the bottom that is nothing but a manual drain even after a separator. You will be surprised.
All feed drops pull from the top of line and then a couple of 90s to bring it downward.

Good luck
Mike

[1 Wild R/T]

The fact your cabinet works good as is & you need to let the compressor catch up pretty well shows a bigger air hose isn't gonna help you much if at all..

Most blast cabinets airflow is limited by the valve more than anything else.... My system is a combination of 1/2" copper, 1/2" PVC & 1/2' flex hose at the compressor but the whip hose that was supplied with the blast cabinet is 3/8"...

I used copper to build a couple condensing coils since water separators don't work until you've cooled the air enough to get the moisture out of suspension....

I actually built a condensing coil to cool the air leaving the pump before it enters the tank... And a second coil at the discharge of the tank...

[70 Challenger Lover]

Wow that looks complicated. Kinda what I was trying to avoid. I think you guys are right that my compressor might be the biggest limiting factor. To be fair, I use it wrong. Rather than keeping the pressure at 80-100 like the cabinet calls for, I run it up to 150. Its harder on the media but it cuts my time down in front of the cabinet which means a lot more to me. At 150, the cfm capacity of my compressor has to be much lower. I probably should try bring it down to 80 as a test. I'm thinking it would have a much easier time of keeping up.

I'm anxious to try out the sandblaster and see how it fares with my compressor. It comes with a variety of nozzles so if the air supply isn't quite enough, I can go down a size in the nozzle and that should keeping it working properly. Might take longer to do a whole car but I'll have to manage until my budget allows for a better commercial grade compressor. Mainly, I want to ensure the sandblaster has a good solid air supply so if I experience problems, I can at least eliminate that variable.

[1 Wild R/T]

I built a more elaborate system then I needed to but basically you need to run the air through copper or iron pipe so it cools, PVC pipe & rubber hose act as insulators keeping the heat in the air & again until the air cools it will hold the moisture in suspension... So at the moment it comes out the nozzle of the blaster the temperature drops & you wind up spraying water along with your media.... You get a clogged nozzle & water droplets on your freshly blasted steel...

Basically you want 50-60 feet of copper or iron pipe before you put a water trap on the air line... A few water drops are a very good idea...  If you study what I did on the bigger coil basically it's just 60 feet of copper with 5 drains in a fairly compact package...  The smaller coil is 16 feet but it's catching water before it ever gets to my tank & it's very effective...

[70 Challenger Lover]

Do all those bends or long runs cause pressure drops or is the diameter of the pipe large enough that it makes up for it?

Does aluminum tubing work as well as copper? I've been considering running aluminum lines around the garage for convenient access points.

[73440]

http://us.kaeser.com/m/Images/Compressed_Air_Installation_Guide_Ebook_0415-tcm266-695991.pdf

Here is a very good compressed air system installation guide.

[73440]

The fact your cabinet works good as is & you need to let the compressor catch up pretty well shows a bigger air hose isn't gonna help you much if at all..

Most blast cabinets airflow is limited by the valve more than anything else.... My system is a combination of 1/2" copper, 1/2" PVC & 1/2' flex hose at the compressor but the whip hose that was supplied with the blast cabinet is 3/8"...

I used copper to build a couple condensing coils since water separators don't work until you've cooled the air enough to get the moisture out of suspension....

I actually built a condensing coil to cool the air leaving the pump before it enters the tank... And a second coil at the discharge of the tank...

Nice work @1 Wild R/T ! That should eliminate most of the water accumulating in the tank that should be drained off I guess.