Paint: Shop tools

[Farrier1951]

OK folks I need your advise. What is the minimum size of compressor I need for my shop. I have one 62 Hawk I am restoring. I need to know what size compressor i need to be able to run air tools, paint gun, sand blaster. I am not going into business, just want to work on one car at a time without being under powered in air.
Thanks for any thoughts

Jim

[gordr]

Get a 5 HP compressor, one that requires a 220 volt supply. You may find some "5 HP" compressors rated for a 120 volt outlet. Forget about it. They won't do the job.

[63 R2 Hawk]

HVLP paint guns, die grinders and sand blasters are all air hogs and require a LOT of air volume (CFM). Bigger is always better, but most of us are constrained by budget. Buy the highest CFM @ 90 psi you can afford. There's a bunch of websites to google, here's one:

http://www.jennyproductsinc.com/howtochoose.html

Look for a good used one on cl, I see them all the time.

[sweetolbob]

Get a 5 HP compressor, one that requires a 220 volt supply. You may find some "5 HP" compressors rated for a 120 volt outlet. Forget about it. They won't do the job.

I agree with Gord unless the magic word "sandblaster" is going to be used to do the complete vehicle. If you plan to blast the whole car, buy a pressure blaster and be aware that you will not be able to keep up with the air demand with a 5 HP. If you are doing individual parts like a fender or less you should be ok. If you plan to do larger sections be prepared to let the compressor cool occasionally. And be sure to use synthetic oil.

I've burned up two pretty good 5 HP units over the years and finally went larger but at this size they are not inexpensive.

If you purchase the 5 HP and you probably should, just be sure to not overheat it. It will handle a blast cabinet, painting and the rest just fine. The 5 HP is a good combination of cost vs performance for the home garage and shop.

Bob

[Warren Webb]

Years ago (1973 to be exact) my wife at the time bought me a 3 hp 220 volt compressor. I apprecialted the gesture but being a body man by trade soon discovered it couldn't keep up, especially when using an air-file (straight-line sander). I bought another 4 hp 220 volt compressor (both had 20 gallon tanks) but that too combined with the first one was barely sufficient. Then in 1986, after moving to a new home I got a 5 hp 220volt compressor with an 80 gallon tank as gordr suggests. It carries the load & does whatever you want it to with room to spare. Now I'm in the 3rd house & will use the old 3&4 hp compressors just for their air tanks for additional capacity.

[kmac530]

As a side note to everyones comments, since I thoroughly agree on the 5 or 6 hp and DEFINATELY on 220v supply, I prefer a cast iron compressor head because they are usually rebuildable.
The aluminum cylindered compressors are use them up n throw them away.
I have a 20 yr old Ingersol Rand 6hp 60 gallon 220v compressor with the cast iron head that I bought new. When it was new it would, and for many years after, it would keep up with any air tool other than sand blasting a bunch. A die grinder, long sander, spray gun or about anything else was not a problem.
A few years back I loaned it to a "friend" to do some body work on his kids car and they used on 110v. Somehow they got it to run on the low voltage, but after they gave it back they complained that it never worked well....I hooked it back up and it kept popping breakers. I took the capacitors off and replaced them for like 25 bucks and the motor works great now. But after 20 years of garage builds and bike repairs, thousands of tires, body work and air grinding the compressor head seems to be a bit slow nowdays....but having a cast iron head unit I can I can hav e them bored and order a piston and ring kit from IR for like 60 bucks I think and good as new...
5+ hp, 60+ gallons and 220v with a cast iron pump....worthy investment of about 500+ bucks to 900 bucks and worth EVER penny.
PS...DO NOT get an oil less pump unit!! and change your oil once in a while with NON detergent oil.

[DEEPNHOCK]

Stay away from an 'oiless' compressor.
Very loud.

[jclary]

I am impressed with the answers to this thread. You folks are "in the know" in a good way. Back when I was in the business of selling air compressors, spray equipment, and air tools...you'd be surprised at how many customers would want to argue with me about the inadequacy of their compressors to do a job. They'd almost always want to brag about how much pressure their compressor was capable of and give me a blank stare when the subject of CFM came up.

In addition to CFM, it is important to "plumb" your air distribution system correctly. If you "plumb" the air lines like water lines...they will be "water" lines. Depending on the size of your shop, your air lines should have about a two degree slant back toward your reserve tank. That allows condensate to flow back to the tank where it can be collected and drained at proper intervals. Air drops should be off the top of the lines and not the bottom. "Drops" should have a valved "dead" leg for draining them at the terminal end and air pulled off from a "Tee" in the line a foot or so above the terminal end.

Rubber air hose should be sized enough to allow sufficient CFM flow for the length of the line and demands of the tool being used. For example, if you have a HVLP spray gun requiring 22 CFM, a thirty-foot long quarter-inch air hose is not going to flow that much air.

For air dryers, make sure they are sized to work at the maximum flow rate your tools will require. Nothing more frustrating than to be painting your favorite car with a very expensive candy apple red paint and suddenly your spray gun blurts out a huge snotwad of water mixed with compressor oil because the dryer couldn't handle the job.

After saying all this, you come to my man cave, and you'll see about fifty feet of a dukes mixture of hose sizes tangled across the ground. Just because I know what should be done, don't mean I do it. However, I rarely use more than one tool at the time, and I have a special "hillbilly air dryer" I rig up for painting.

[brian6373]

I also vote for the 5 hp 220 v compressor. There is one thing you can do to make your compressor seem "larger". Find a large reservoir and plumb it in, it will allow you to use a large draw tool longer before you have to stop and let the compressor "catch up". For really largr jobs like blasting a whole car or frame, go to your local rental store and rent a towable rotary compressor like they use for jack hammers. It saves a lot of time not having to wait on your compressor to build up pressure. As posted above, air motor tools like die grinders and needle scalers use a large volume of air, 12 + cfm, also the air tools you buy make a difference. As a rule the cheaper ones tend to use more air. The new generation of professional air tools made of composits are lighter and more efficiant, tending to use less air. For hobby use, the stuff from H. F. works just fine, and is inexpenssive. The other issue with a.c. is the noise. I put mine outside after building a doghouse for it and plumbed it inside. 3/4 black steel pipe will flow all the air you want, and is easy to work with. One last thing, Air compreeors need to be drained of condensate. I took out the petcock on the bottom of the reservoir and used some copper tubing to a ball valve. it makes draining much easyer.

[ken-renda]

OK folks I need your advise. What is the minimum size of compressor I need for my shop. I have one 62 Hawk I am restoring. I need to know what size compressor i need to be able to run air tools, paint gun, sand blaster. I am not going into business, just want to work on one car at a time without being under powered in air.
Thanks for any thoughts

Jim

This was good discussion on air compressors. When switching from air tool use to painting, a new hose is alway used, the tank drained and a total of three fllters are used, two at the compressor and one small filter at the base of the gun. I'm about ready to switch over to paint and have have considered, somehow, cleaning out the 60 gal tank and a neighor has suggested running a coil of hose line thur a tank of ice. I'm an amateur at this, comments please. Ken, Deltaville, Va

[tbirdtbird]

OK, jclary, don't keep us in suspense, we need more details on the "hillbilly air dryer"

[jclary]

Years ago, I had a customer that manufactured after-coolers for HVAC systems. On one visit to the plant, I saw a new condenser, about the size of a truck radiator, placed in a pile of trash headed for the dumpster. I asked the supervisor why they were throwing away a new unit and he explained that it was a left over unit that was obsolete and not longer being used. He said if I had a use for it, I was welcome to it.

I took it home and mounted it on an old shop fan wheeled dolly. I installed a quick disconnect on the bottom port. On the other end, I mounted a vortex air/moisture separator with an automatic drain valve. Next inline is a 2 micron particulate filter, followed by another quick disconnect fitting. On mild, low humidity conditions, I simply use a small window type fan to circulate and cool the air as it passes through the radiator. As condensate drops out of the air and reaches a certain level in the vortex filter...the float activates and dumps out the water. On real humid hot days...I run a cascade of water from a garden hose over the radiator. If I had a nearby stream on my property, I would place it in the water. However, this "Hillbilly" solution has worked well for me so far. When I am finished painting, I disconnect the fittings and roll it aside.

Ken, you are correct to use a new hose for painting. Old air hoses can become dirty with moisture and small amounts of compressor oil. Never use a line with an automatic oiler installed for tools to spray paint (DUH...). Don't want to insult anyone with this little reminder, but you'd be surprised at the crazy things I have encountered over the years.

[Farrier1951]

Darn you guys are GREAT!!! So now I know about 199 times more than I did before. Thanks a million. Gonna start looking for real now!

[feralcat0_0]

Gentlemen, I use an automatic drain on my compressor that I got from HF.(Automatic drain, not compressor) seems to work pretty good after I shut it down. Any reason not to?

[kmac530]

Never seen one. Got a link to it we can see?

You are not just talking about a spring loaded pop off type check valve that you have to pull the ring and the air blows out, are you?