Air compressors

I am in need of an air compressor and air tools. I have been meaning to buy one for a few years but now it is time.

Will a small portable compressor be sufficient to run an impact? What are the minimum specs I need to use air tools?

I'm working on changing the transmission in a Miata and the tools I have just aren't working out.

Something I learned about compressors: the 110v 'oilless' uprights are not much cheaper than the low end 220v vertical stationaries and the stationaries put out a LOT more CFM. You can make a cord to connect a stationary to a dryer receptacle. The hard part is moving the damn thing around.

I'd not want to go under about 9 CFM at 125 PSI, FWIW. I also learned do NOT use extension cords. Instead, run extra hose. A compressor draws so much amperage it can literally melt the average 'Home Depot' extension cord. If you run hose instead of cord, you get around that.

220V isn't an option right now. I am renting and there is no easy way to get power from the dryer outlet to the garage.

If you are definitely limited to 110v then I'd go for one of the belt drive uprights with an honest oil type compressor. Home Depot has the VT6315 which is probably pretty much the norm for that type, it's $379.00. It's limited to 90 PSI at 6CFM, so if you get into a high useage operation and it runs out of oomph halfway through you will probably have to wait till it repressurizes to get anything further done.

unfortunately, I am limited to 120v. Should be good for air tools though. After destroying my shoulder wrenching on the saab this past feb.. I think airtools are a sound investment

You can run an impact off a pancake compressor all day. You can run a cutoff wheel or 90 degree grinder with a Rolock wheel for cleaning gasket surfaces but it will die out quick. Expect 2-3 recharges to get a gasket surface clean on anything but a tiny part. Dont think of wizzing out a whole panel with a pancake compressor or anything less than a 220V 60 or 80 gallon upright compressor.

Unless you are doing bodywork, the only air tools I would suggest for the shadetree hackjob home mechanic are a nice 1/2" drive impact and a 90 degree air grinder with a rolock wheel attachment. Anything else is more of a hassle and liability for the marginal time savings.

Don't underestimate the difference between good air tools and Harbor Freight specials. I run Ingersoll-Rand tools and wouldn't use anything else. Snap-On tools are also good. Good air tools run much more efficiently so you use less air to do the same work. The cheap air tools are really good at turning compressed air into noise and really bad at doing work. A $300 impact wrench may seem like a lot of money, but with proper care its a lifetime investment.

For the record, my $20 yard sale 25 gallon Craftsman compressor will run all 32 lugnuts off and back on my Dodge without needing a recharge using my IR 2135Ti rattle gun.

Have you looked at cordless impacts yet? You can get really nice 3/8" and 1/2" cordless impacts from DeWalt, Makita, and Snap-On. They will do 99% of the work of an air powered gun and don't need a compressor. I would argue that a cordless 3/8" impact is a better tool than an air powered 3/8" impact due to similar size, weight, and power without the need for a compressor, hose, line oiler, dryer, and so on.

Get the biggest tank you can manage. We've got a 2* gallon craftsman compressor. we have it running with about 75-100 ft worth of hose (not line) and an ingersoll rand impact. we can not do all 4 tires on a car without it running. I can not stand the thing. we are trying to find an 80 gallon 220 now so we can stop having it constantly running when we do work.

I will echo 92GSX comments about air tools. spend the money and get decent stuff. IR makes good stuff. The IT 2131 line of impacts are very nice. I traded my Mac impact in on an IR2131 because I knew I'd be leaving the dealership and wrenching at home and the 2131 line are very quiet. It doesn't have the balls that the Mac did, that thing would rotate the whole car around the lug nut if the nut was tight enough but it's very adequate.