Help plumbing air drops

[dlmos]

I'm getting ready to plumb the air lines in my garage and had newbie question. I'm looking at putting in one drop with a 1/2 inch filter/regulator/lubricator for tools and then a second drop with a 1/2 inch filter/regulator for painting/sandblasting and using the disposable dissectant filters for the paint gun. My outlet on the compressor is 1/2 inch and I was planning using 1/2 pipe for the drops with a drain below each of the two drops. Am I missing anything here? And does brand make much of a differance with filters? I was looking at the ones from harbour freight and northern tool but don't want to scimp and then pay later. Also do you just use a reducer after the filter to drop it down to 3/8 or 1/4 for the quick connect or is there a better way?

Sorry I've been asking so many goofy questions lately, but hopefully once this is done I'll actually be working on the M715

[randygar]

Well, the first thing about drops is that they're like toilet seat covers. First up, then down. A lot of water will condense in your main pipes (and DON'T USE PVC, by the way), and if you run your drops up before going down, the condensation will stay in your main lines and run to a drain at the end, rather than need to be removed by your filters.

I've had good luck with the harbor freight filters, but I've never done any good comparison to a real filter. A filter right at the end of the hose will catch a lot of water one on the drop misses, I've found.

I've heard a number of people recommend a refrigerated dryer (HF sells one for not too much) over or in addition to disposable filters. The initial cost is higher, but the long-term cost is lower if you do a lot of painting. If painting is only an occasional thing, desiccant will be cheaper.

Yes, just use a reducer after the filter. However, if you're going to be running a blaster that's not tiny, a 7" sander, a 3/4" or larger impact wrench, or any other large tools, you'll want to go with at least one 3/8" air coupler with 1/2" hose, which will need larger fittings. A big impact gun on a 3/8" hose runs at about half power, as does any decent sized blaster.

I don't like inline oilers, as they slime everything. Any hose used with an oiler should never be used for painting. Any tools used for body work (sanders, etc) should be manually lubricated and let run for a few minutes before using them on a vehicle, or they'll get oil on the surface too. I just give all my tools a good squirt of name-brand air tool oil before and sometimes after each use, and no problems yet. And don't even think of using a blow gun with oiled air...

While I've had good luck with the HF filters, I did get a defective one once (part of the filter+regulator+oiler combo) that exploded. The big part of the housing left a nice bruise on my leg. Always wear safety glasses.

It's easy to not add enough drops, so add a couple extras where you might need some later - at your workbench, by your shelving/storage, whatever.

--Randy

[phoenix]

I painted my 1967 Mustang in the humid summer and had problems with the water in the lines even after I installed two filters, so I took a small air tank that I had around, a small propane tank would work, and stuck it inside a bigger container that was filled with water and ice. I had the inlet line coming into the tank at the bottom, and the output line at the top. It works very well if you only paint once and a while. I have found that copper pipe is the best for air lines. It disipates the heat very well, and helps to condense the water since it is cooling it. It is cheaper than the aluminum air line kits you can get, since the fittings on the aluminum kits are very expensive. The thicker black pipe holds the heat of the air in and doesnt condense the air as fast. The copper line is much cleaner in the inside too, so there wont be any contamination for your air tools or paint gun.

[george walker]

One thing you need to consider in air tool plumbing and operation- C.F.M. is as important as P.S.I.. You can have 170 psi but if it takes to long for that press to move through small lines or fittings it will really affect tool performance. Most tools have these specs in there info., you need to know what tool you will have that uses the largest C.F.M. and design for that, If you are getting a blaster that will prob. be the biggest user.

[osut362]

look around at the mom & pop tire, auto repair, ect. shops and most use pvc pipe. i've used it for years and have had no problems. be sure and use a rubber or flexable air line between your compressor and your rigid piping....al
check the link below, it will give you a good primer on air piping.
http://www.tptools.com/StaticText/ai...ng-diagram.pdf

[Snookie]

DO NOT USE PVC FOR COMPRESSED AIR LINES!!! Copper lines split when they fail. PVC explodes and sends shrapnel flying when it fails. I won't stay in a shop with PVC air lines if they are pressurized. Don't take my word for it, do your homework.

[dlmos]

Just wanted to say thanks to everyone for the advise on this, I just finished plumbling all the lines today and not a single leak! I ended up going with 1/2" black pipe and fittings, and made sure all the drops went up first, then down. Each drop has a tee in it to the air filter on the side, and a drain straight below, and a main drain at the end of the line. My blasting cabinet drop is about 30' downline from the compressor, so hopefully that will help with condensation, it also has a seperate filter for it as well. Someday soon I'd like to get the refrigerated dryer, but at least I'm up and running at the moment. Thanks again for the help!

[randygar]

Sounds good!

--Randy

[randyscycle]

Here's my experience:

I have a 3000 Sq Ft shop. plumbed with air in every corner. I have an 80 gallon 2-stage compressor with a 6 HP motor on it, 240 volts. Where the air line leaves the compressor it is 1/2" all the way to everything. I used copper pipe for all the air lines.

I have one huge air consumer, and that is my bead blast cabinet. Its a circa 1973 Trinco cabinet that will fit most motorcycle frames inside it. When I blast with it, which is pretty much every single day for at a minimum of 2 hours, sometimes all 10 or 12, the compressor will run nearly constantly. I added another 60 gallon tank to the system last year. This kept the compressor from kicking on quite as soon, but it also made it run twice as long to fill two tanks now. Lots of volume, same pressure.

If someone is blasting in the cabinet for any length of time, there is a noticeable difference in the performace of any air tool anywhere else on the line until the system recovers.

Just make sure you have more than you think you'll ever need is my point.