I have been thinking/looking at buying a compressor. There is so much information that I am confused. So how big do I need it to be, 30 gal or 60 gal seem to be the two choices? The plan is to do some body work and I am looking at doing my own painting as well. Budgeting is important as well, it is just for me so no need to have the cream of the crop or the biggest monster compressor I can find. The info I have seen all seem to say get a 60 gal but the teacher I have for body work says he does everything with a 30 gal. Just needs to stop sometimes to allow the compressor to catch up. I have seen a couple at Princess Auto that have good reviews, your thoughts as well.
Could also use some thoughts on air drier and oilers. What do I need/don't need?
I'm sure you will get lots of opinions. This is my opinion-- painting doesn't take a lot of air volume -- the more money you spend on air filters the better quality the filter is. -- NO oilers or lubricators ever!!!! once a air hose is connected to a lubricator the hose is contaminated. Buy a $2 oil can to oil your tools. -- Have a filter right at the compressor.
I bought one of these http://www.tscstores.com/COMPRESSOR-60-GAL-VERT-DEWALT-P40978.aspx#.WU3E8mjyu00 from TSC 2 years ago when they were on sale for 50% off. It does everything I need and it was reasonable. If I was younger I would have bought bigger and better but for one old guy it does a good job. I used to have a larger unit but the physical size was too much for where I wanted to put it. I have air lines all the way around the shop. I think about 160-180 feet in all. I have drops and outlets every 10 feet with a filter and reg. on each outlet. I'm real happy with it. TMJ
-- Edited by toomuchjunk on Saturday 24th of June 2017 08:20:59 AM
My 3HP/30 gal. compressor...I smoked my pump (one weekend, running it non-stop), doing body work & running an air file board: - 1 to 2 minutes of filler sanding & air runs out - 8 minutes waiting, to refill tank
^^ Do yourself a favor, get a 5HP/60 gal. 220V...your teacher is giving out wishful advice, on 3HP being adequate.
Now I have a true 5HP-220V, 2 stage with 80 gal. tank - zero wait time. - a hobby shop compressor, I picked up used - has a USA made Baldor 1725 RPM motor vs. 3450 or 3600 RPM - slower speed is much quieter operation & allows good quality Pumps to last for decades
-- Edited by Beaumont67SD on Friday 23rd of June 2017 10:59:17 PM
I had a 60 gal 5hp and once I started doing bodywork it wasn't enough. I have a 80 gal two stage industrial compressor now. The lower RPM's really helps as well as the CFM's.
A rule of thumb I learned is always get the biggest(or build the biggest) you can afford-no regrets that way.
a little input maybe, as for sizing of a compressor i don't know a whole bunch about the pro's and con's of what is the magic combo for the best or proper sizing. like they are saying above it probably boils down to the intended usage or purpose and that makes sense. but what i learned after the fact, dam-it, was that i should of asked for more input on what i used for sizing of the air supply lines to my outlets. when building my shop, 30X50ft, i installed 1/2" copper lines into the wall with 5 outs on each side and 2 on each end with one built into a corner where the future compressor would sit for the supply into the system then dry walled over thinking this was pretty slick with no external piping. found a fairly new 5hp, 80gal 230v at a good price and put it in, that's where the slick part ended, another dam-it. lol bought a good size sand blasting cabinet and hooked on about 50ft from the compressor and kept running low on pressure and the compressor not coming on when i thought it should due to lower pressure but still had lots on the gauge, ???. brother drops in one day while i am using it and cursing at it as the pressure drops and asks what i had for piping in the walls. he is a union plumber/pipe fitter who has worked on bigger jobs for years and tells me i screwed up on the piping size and probably the material, copper, as it is in the walls and more susceptible to temp change being in the walls, moisture. tells me i should of put 3/4" for volume and probably on the outside of the drywall for more constant temperature using copper not steel, less moisture. i moved the cabinet over to about 10ft of the compressor and it was much better but not best i don't think for the compressor size. - anyway, just thought i would throw this in there. once you figure out the comp sizing don't choke it off with undersized piping like i did. i should of known better as any of the truck tire shops you go to use 3/4" hose to run their big air ratchets not 1/2" like most other garages. dummy me, lol.
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"if you are not the lead dog, the view is all the same"
If 3/4" lines are used, what is a good brand of filter to use at a reasonable price? This is for a home shop not commercial.
When I worked at the big house for 30 years we always ran 3/4" then cut down to 1/2" for the filter/FLR.
In my shop because it was fed in the middle of the run and I had all the brackets I only ran 1/2". It works good. The hose you use is a major component as far as volume loss goes.
^^ that 's what I did as well.^^
3/4 black pipe for the main line, "T" up to ceiling, then back down reduced if needed to 1/2. Going up off the main line helps with the water issues. I also put ball valve drains on the end of every line at floor level. Another thing to remember is that you don't want your air/dryer too close to the compressor. I think 10ft of pipe is advised between them but not sure. It gives the air time to cool down I believe. You also want to slope your lines to allow water to be drained.
Thanks guys for the help. I was looking at videos of air dryers, all of them seem to be right off the compressor. Slab you suggest running 10 ft first. What is better?
Thanks guys for the help. I was looking at videos of air dryers, all of them seem to be right off the compressor. Slab you suggest running 10 ft first. What is better?
X2--my filter is about 3ft from the comp but i understand the logic of what you are saying, makes sense. another dam-it, lol.
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"if you are not the lead dog, the view is all the same"
I have to agree with the 60 gallon and 5 or 6 hp 220volt. You will never regret it. I started off with a 30gal 30 years ago and I am sure that even with the HVLP spray guns of today I would not be as happy as I am with the 60gal. If you are careful and check CFM requirements with air tools you collect, this will make a difference for you too. Some of the old air tools will gobble up a lot of air when in use. My unit is a 6hp 60gal Campbell Hausman I bought about 20 years ago. I have totally restored several cars including paint and I am still very happy with it.
I have been using the tube style air dryer using pellets which seems to work quite well (bought it at Princess Auto). Prior to this I had a water separator however if it was less than 15 feet away from the compressor, the water would blow right through it because the air was still too hot, more like steam. Had to remember to drain it often.
There are several suppliers out there depending what you want, a major difference is oil-less vs oil. Oil-less is very noisy so I have never owned one and cannot comment on performance.
I can't remember where I read about the air dryer distance from the compressor or if t was something I was taught in bodyshop school. Like mentioned above, it is about cooling the air a bit before trying to separate water from it. I am running a electric dehumidifier type air dryer that has Freon in it I believe. I also have the cheaper water traps on every down line. I ran 1 inch pipe into the air dryer and 3/4 out. I have a more expensive Devillbis water separator in the paint booth as a last chance. Water in your paint sucks. Anything to do with sandblasting will require a big compressor with a big tank. The best being a diesel engine powered compressor on wheels! LOL
Rich
The 30 gallon is not enough. 
