Air Compressor...for the garage - PeachParts Mercedes-Benz Forum

sknaffl · #1 06-08-2009, 10:11 PM

So...I've been considering buying an air compressor for the garage for years and I think I'm about ready to pull the trigger on purchasing one. I'm planning on doing the a/c r&r on the W116 in the next couple of weeks and I will need compressed air to blow out the lines, plus I would like the option of using an impact wrench for any future projects....really I just want an excuse to finally buy one!

I've searched Sears, Harbor Freight, Northern, and Home Depot. I'm not really sure what I should be looking for on PSI, HP,holding capacity and if the brand is really that important.

If anybody has any advice on what would be a good set-up for moderate use, or could tell me what you've got in your garage...and if you are happy with it or not...I would greatly appreciate it.

Thanks!
Sam

kerry · #2 06-08-2009, 10:49 PM

I've had some tight lug nuts recently that required a 1" impact wrench to loosen. After goofing around with my own compressors for a while I finally concluded that no 110 volt compressor would have the volume necessary to operate the wrench. The bigger the tank the more air you have to operate an impact wrench. A 5 gallon Harbor Freight pancake has been adequate for most of my other needs. I like it's portability to I can blow out my sprinkler systems.
I just picked up a used Campbell Hausfeld 30 gallon 135psi like new on Craigslist for $200. I also have an old belt driven oiled Craftsman that will still be running when I am long gone.

DSlater · #3 06-08-2009, 11:02 PM

I inherited a Craftsman compressor with the house I'm in. I love it. It has made keeping the tires on my vehicles inflated properly at all times much less of a chore for starters. Over the years the fuel savings from that alone could pay for one. And an impact wrench was the only way I could get the drain plug out of my differential, but I'm not a big dude. For the same reason, it makes lug-nuts much less of a hassle. Was also absolutely must have when I did battle with the huge nut holding the front chain gear on my motorcycle. The list goes on...

The one I have was not working when I got it (well, might have run for a while but was bleeding lube everywhere). After looking into whether to replace or repair, I decided to repair for two main reasons: replacement cost and it's oil-lubed and uses a belt-driven flywheel. It seems much like our diesel Benzes, keep it lubed and maintained and it will run nearly forever. The electric belt drive motor can easily be replaced if it ever burns out. Got $25 worth of gaskets from Sears and it runs like new, reaches cut-off pressure in about 30 seconds.

This is nearly the exact model I have, but mine is old, red, 20gal, has hard wheels, and didn't come with gauges/filter:
http://www.sears.com/shc/s/p_10153_12605_00919541000P?mv=rr

I'd say lurking the craigslist ads for the towns in your area for a while could pay off.

pawoSD · #4 06-08-2009, 11:07 PM

Get as big of capacity as you think you will need, then choose a quality made unit thats oil-lubed. They run quieter, and last WAY longer.

What I want is an air compressor that can be mounted to a 617 engine in place of the A/C compressor.

Then put a 10 gallon air tank in the trunk, run some lines, and a switch to engage the clutch, and you have a 100hp super high pressure/volume air compressor where ever you need it!

charmalu · #5 06-09-2009, 12:54 AM

I have a 20 Gal 4 HP Campbell Hausfeld. It`s good for blowing up baloons and checking tire pressure.
Can`t really run any air tools with it, it runs out of oomph, take too long to catch up. I was using my paint sprayer and it couldn`t keep up.

problem with a too small compressor, is it constantly runs and you have hot air, then the air cools in the hoses and moisture condenses in the lines.
with a larger unit, they don`t run as much, and the air has some time to cool, which lets some of the moisture to drop out in the tank.

you do need to have good air filters and moisture traps.

The oil less units are really noisy compared to the oiled compressors.

two stage are more efficient than single stage compressors. 2 stage usually pump up to 175# compared to single stage 125#.
2 stage cost quite a bit more.

If you decide to buy a used one, check for rust in the tank, I bought an old used one 15 yrs ago, had a 60 or 80 gal tank, 5 horse honda gas eng. and huge 2 lunger compressor. that thing could really pump some air. the problem with it, the whole thing was cobbled together. I used it mostly for body work, painting etc... had to leave the bleed open to keep pressure where I wanted it, and it didn`t have any way to idle the engine when it reached pressure.

I opened the large plug on the end of the tank to take a peek in side ( do this when the air is depressurized

) and was surprised to the amound of rust inside, thick blistery. date on info plate was dated 1946. so I sold it as soon as I could

.

then I went too small compressor

Charlie

vstech · #6 06-09-2009, 08:26 AM

I have several air compressors. the bigger the better. for what you are describing, you should be fine with a 30 gallon unit. but look for one with an oil filled compressor. also, look at the motor and VERIFY that it will handle 240v. some motors say on the data plate 110/240... but the posts to rewire for 240 are not present. (ask how I know...) a 240 motor starts WAAAAAAY easier! (my current 110v motor will kill all the lights in the shop when it starts...) My Mercury vapor stall lights take SOOOO long to restart after they drop out from the pump coming on.
if you plan on doing any body/painting work, you will need a good dewatering system. if you plan on using an impact gun for more than tires, 30 gallon is going to run the compressor ALL THE TIME... move up to a 90 gallon tank.
if you go with a used tank look it over carefully. I got one, and there were pinholes all over it. water does a number on a steel tank! what ever tank you choose, remove the petcock that comes with it, and install some brass pipe and a real ball valve where you can reach it to drain the water that collects in the tank.

tbomachines · #7 06-09-2009, 09:02 AM

Quote:

Originally Posted by pawoSD

Get as big of capacity as you think you will need, then choose a quality made unit thats oil-lubed. They run quieter, and last WAY longer.

What I want is an air compressor that can be mounted to a 617 engine in place of the A/C compressor.

Then put a 10 gallon air tank in the trunk, run some lines, and a switch to engage the clutch, and you have a 100hp super high pressure/volume air compressor where ever you need it!

I have heard of people plumbing the A/C compressor to simply pressurize air, though not on MBs. Air ride suspension and train/semi air horns here we come! Maybe you can stick a few hoses out the back for some extra thrust up the hills

pawoSD · #8 06-09-2009, 10:12 AM

Quote:

Originally Posted by vstech

I have several air compressors. the bigger the better. for what you are describing, you should be fine with a 30 gallon unit. but look for one with an oil filled compressor. also, look at the motor and VERIFY that it will handle 240v. some motors say on the data plate 110/240... but the posts to rewire for 240 are not present. (ask how I know...) a 240 motor starts WAAAAAAY easier! (my current 110v motor will kill all the lights in the shop when it starts...) My Mercury vapor stall lights take SOOOO long to restart after they drop out from the pump coming on.
if you plan on doing any body/painting work, you will need a good dewatering system. if you plan on using an impact gun for more than tires, 30 gallon is going to run the compressor ALL THE TIME... move up to a 90 gallon tank.
if you go with a used tank look it over carefully. I got one, and there were pinholes all over it. water does a number on a steel tank! what ever tank you choose, remove the petcock that comes with it, and install some brass pipe and a real ball valve where you can reach it to drain the water that collects in the tank.

Lol.....perhaps its time to add an additional circuit for the compressor?

Or....upgrade to nice high efficiency fluorescent lighting?