Air Compressor Recommendations

[kevinrude]

I recently acquired my 5th or 6th JW/Lighttwin and this one, like every other one I’ve ever gotten, has been dropped on its head at some point in the past. So, I thought I would put to use what I learned at Constantine this year and see if I could blow out the dent using an air compressor. Then I got to thinking that if I got an air compressor, maybe I should get one that I could use for spray painting, powder blasting and pneumatic tools as well.

So I guess that’s my question, can I get just one compressor that can handle all of the above functions? I know to do gas tanks you need really low PSI (like less than 10 or something) but need higher levels for the other functions. Can one compressor do it all? Any recommendations?

Thanks.

[gjonz]

I bought a rather large 60 gallon or some such thing. 240volt. But keeps up with tools and blasting gear.

It’s my belief the big box stores and Harbor Freight are all selling the same ones, rebadged. It’s a five hp I think. Double cylinder.

[frankr]

You use a pressure regulator at the tank outlet to control lower pressures than what is in the air storage tank. In other words, 100 psi in the tank can be regulated to 10psi (or whatever) at the job/tool.

Just an opinion—I bought a new oiless compressor to replace my old Sears piston type. I hated it. It was LOUD! I wound up selling it at a loss and buying parts to repair the Sears put-put. Still puttin’.

[wiscoboater]

When shopping for a compressor always look at the CFM @ 90psi rating. Most tools operate at or around that range. More CFM then you need is always better. Most modern HVLP paint guns operate well below 90psi, but tools like say a DA sander or a sand blaster/soda blaster will need large volumes of air for extended periods of time. This is what’s referred to as CFM, or cubic feet of air per minute. A good rule of thumb when buying a compressor is find out the CFM requirement of your tools and buy 15% higher CFM then your most air thirsty tool. That way you will never have to sit and wait for your compressor to catch up, or worry about it overheating. Keep the filters clean, change the oil often and keep the tank drained of water/condensation and it will give you many years of good service.

[Mumbles]

What you want to look for in a compressor is its CFM (Cubic Feet Per Minute) rating, not the pressure it can develop so much. Most compressors will put out 100+ PSI but they have to put out at least the minimum volume your tools or spray gun will demand of it. There’s nothing worse than running low on air halfway thru a paint job and having to watch your paint set while waiting several minutes for the too small compressor to build up air again.

If you want a large one, keep your eyes open for a body shop going out of business or upgrading. I found this 5HP DeVilbiss two-stage that way cheap and it only needed a guard made and a main switch. It puts out enough air to run several tools at once and has enough volume for beading or sand blasting.

Another option to get the volume is to hook two smaller ones together like these ones are. They aren’t in a shop but are used for charging a dry sprinkler system. When servicing them, I run them both together and they put out a pretty good breeze.

[wiscoboater]

Mumbles, That red one seems to be missing something up top!

[Mumbles]

Yeah, it had blown a head gasket. It’s kind of funny how hot they can get running continuously before someone discovers it! 😀

[20mercman]

I have a "Classic" brand two stage 5hp 80 gallon tank compressor. I have another 2hp 22 gallon tank that I struggled with for years until I broke down and got a real unit. If you plan to do more than hobby work, I would highly recommend that you get a real unit. The old unit would run out of air running a DA, you would have to carefully time your work to let the compressor catch up. Also, it was running all the time you were using it. It gets tiring having that noise all the time. I now can run ANYTHING with the new unit. Over 20 CFM at 90psi.

Steve

[wbeaton]

You need to determine the maximum amount of air you need and then pick out the air compressor. Don’t worry about hp. They are usually over rated. 1 hp = 746W and a 110V 15A plug outputs a max of 1500W. That means you can’t get more than 2 hp out of a standard 110V outlet. You can run a maximum of 5 hp on 220V wiring if it’s wired correctly. CFM is a better way to pick a compressor. Just know that those numbers can be biased as well. A compressor will output about 3-4 CFM per true hp. A two 2 stage compressor will output 150 psi whereas a single stage will output 100 psi. A single stage is all you really need.

I paint outboards and run tools with a small 1/3 hp 8 gallon compressor. It outputs 3.7 CFM at 90 psi or so it
claims. I suspect it’s less than that. I also bought a good quality old (1968) single stage 110/220V compressor with a true 2 hp TEFC motor and 60 gallon tank off the local buy and sell website last year for cheap. I would go this route if you have the space. I use electric DA sanders. I don’t like pneumatic air sanders. JMO

Wayne
Upper Canada Chapter

uccaomci.com

[kevinrude]

Thanks for all of the info, guys. A lot for me to digest.

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