Compressor size????

[00XJ]

So I have been reading up on the plasma alot lately and the general impression is to not go with the internal compressor for many reasons and I understand all that but my dilema is for those of you that this set up already what size of compressor do you use to supply the plasma? Do you need to as large as a 60 gal or can you use a smaller unit? Thanks for all the help!

[Wyoming]

A smaller compressor will work where a larger one won't...and vise versa. It all depends upon how you pipe the air flow after it gets to the tank and before it gets to the plasma cutter. Air tank size isn't the limiting factor here, moisture is. An on-board compressor leaves the least possibilities for dry air since the tank, if there is one, is small, piping is severely limited and there isn't much room in the box for coalescing filters/moisture filters and such.

I would be more concerned about the air lines and filters after the compressor than the size of the air tank. Install as long a run of air line as possible prior to your first moisture/coalescing filter so that the air from the compressor's heat cycle has a chance to cool and allow the air to "shed" its bonded moisture. This can be done as simply as running the air line up to the ceiling and down to the floor a number of times...or across the back wall. A tank mounted "spitter" isn't a bad idea as well. Finally, a good quality moisture filter at the back of the plasma cutter should have you up and running with long consumable life if you've installed all the other "fixes".

[00XJ]

Thanks for the quick response, so would a 6 gal compressor be enough if done right? Sorry more questions but I wanna do this right the first time. Thanks!

[Wyoming]

I need to run off to work right now, but what sort of pressure and volume is that 6 gal. unit putting out? If it is rated to meet your plasma's needs and you run sufficient air line and filters to cool/seperate the water from the air you should be okay. One advantage of a long run of air line is increased tank size from the added sq. ft. of line if you run your regulator at the end of the run. Make sure your compressor can keep up to the demands of your plasma. a 6 gal. unit will be running nearly all of the time so the air will not have much chance of cooling down other than via your air line.

[00XJ]

Thanks, appreciate the info.

[Pumpkinhead]

Along with what the wise Mr. Wyoming sez.
I'd like to add that with any compressor and long lines be sure up-size the pipe. long runs of pipe the same size as the compressor's outlet will reduce the volume at the terminus.
That's to say, that if the 6 gal. unit which, dollars to donuts, has a 1/4" NPT outlet is rated at 5 CFM and you have a long run, especially one with a lot of el's, you won't see 5 CFM at the tool.
Also those lil' units typically come with quick disconnects, if you aren't using it in a mobile capacity I'd remove it, they are very restrictive. If you are using the compressor mobile I'd up-size the Q-D to a 3/8" and use 3/8" hose with the 1/4" quick disconnect at the tool end (most tools use 1/4" Q-D nipples).

[00XJ]

Thanks for the replies, gonna go do some browsing today. Thanks!

[Wyoming]

Thanks for the quick response, so would a 6 gal compressor be enough if done right? Sorry more questions but I wanna do this right the first time. Thanks!

OOJX,
Okay, back from work. Opinion only, but if you truly wish to do the job right the first time I would rethink your selection of the 6 gal. compressor. You are going to be on the ragged edge of the abilities on such a small compressor. If that is what you have already, go ahead with it. If not, buy one in a larger size with more performance and grow into it with other uses. If you have the compressor already and it is an oilless...trash the noisy pest so you won't have problems thinking over the din.

Pumpin'kin,
An attaboy from you...I feel so dirty.

[Sberry]

Those little comps have their place but not to run tools. There is no substitute for horsepower. Anything that runs from a 120V circuit is limited, about 5 or 6 cfm tops. Some of these units, the single stage ones with 60 gal tank are really a bargain for 400$ or so, they are also marginal for real work but passable for general DIY stuff,, they will run impact, air ratchets well and some air tools for short durations.

[Wyoming]

Those little comps have their place but not to run tools. There is no substitute for horsepower. Anything that runs from a 120V circuit is limited, about 5 or 6 cfm tops. Some of these units, the single stage ones with 60 gal tank are really a bargain for 400$ or so, they are also marginal for real work but passable for general DIY stuff,, they will run impact, air ratchets well and some air tools for short durations.

Yep, I have a small Porter-Cable pancake for the wife's air nailers. Hate the darned thing whenever it kicks in...dogs run and hide in the basement. Quincy 80 gal. sitting happily up at the shop.

[00XJ]

Well I ended up going a little larger than the 6 gal, bought a 26 gal for a good price and came with a 40 piece tool kit. No 60 or 80 gal but for me I think it will be plenty. Thanks for the help guys!

[Sberry]

What electric does it plug in to?

[00XJ]

Its only a 110v but for me I believe it will be enough.

[Larwyn]

I've gotten good results running my Spectrum 375 Extreme on a 25 gal 120 volt Husky compressor and even on the little 4.5 gal 120 volt DeWalt. It might do better with a larger compressor, I don't know, but I am more than satisfied with the cuts I get so far using either of these two small compressors. I would still like to have a larger compressor in my shop, for many reasons, but I am happy that I get satisfactory results with the little DeWalt when I need to use the PC away from my shop.

[Sberry]

The tank size will help SOME but is still limited by the available input power.