Old Craftsman 33Gal, 125psi, 10.1scfm compressor help please

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PostPosted: Fri May 26, 2023 10:55 pm
Is anyone familiar with this compressor that can advise me on pros and cons and how to put in order and get it ready to paint HVLP with it.??

Craftsman 5HP 33gal 125 psi 12.2 scfm@40 and 10scfm@90psi

So here is the compressor I got today. Its probably 20 years old but it was only 200 bux and I was going to shell out 75$ for a rental anyway. Price could have been better at 100$, but... I just figure I can rebuild on this tank platform slowly, or sell it for similar amount when done... Its a 220v hookup which I had a short extension cord for a table saw already. The compressor has (What I thought was) a factory 220v plug and 8 ft electric cable and is not intender for permanent wiring. NOTE that if you look at the example pic I have attached they have really cranked us the size of the plug and wire on theirs. Perhaps there was a reason. I know I should have got some opinions FIRST, but I did not want to spend any more time anguishing over whether to rent a compressor and possibly not get done in that weekend, or take a chance on that 700$ Dewalt at Tractor supply financed.

Not sure about the actual age of it but its old enough that Craftsman also has THEIR NAME stamped on the GE motor label...

It takes 3-5 mins to fill from empty and shuts off at 125psi (have not formally clocked it yet). It kicks back in around 90-100psi. I can't really judge based on my hand air sprayer tool I was testing with is junk and was probably only allowing 4scfm at most.

Finally I did note some oily murk on the bottom side of the tank after the seller drained it to see how much water was in it. He remarked how little water there was but I could tell he was not too informative about the oil that came out with it. All said though he stated this compressor came for free years back and its just been sitting inside mostly never hooked up aside from some rare projects and tire filling. But I am concerned about the oil. It wasn't too bad and probably just rust mixed in more likely on the oil color.

The air tank is impressive looking and I speculate built back with they really made things well. I also notice it has a large removable plug-screw on one end that you could get an entire water hose and more in there for service.

I'll put up some pics tomorrow like I said, but perhaps someone has something to say about all that in advance..?

My initial concerns are..:
1) I need to check the LOOK OF THE OIL and most likely drain and fill. What are my concerns to look for and what type oil to go back with?
2) Other than that for now I did not note any gross impurities in the line output, and even holding out the relief valve it did not seem to spew anything other than air. But there is some kind of smell going on, and I am thinking its all just old. For all I know any smell could emanate from the compressor motor. I did not check the oil lever come to think because he ran it for me. There does not appear to be a sight glass it just looks like there is a drain plug and a fill plug right on top an inch up..

Thinking more about the subject of actual REAL SCFM achieved at the objective tool, how do you know what you are really getting. Is the best way to simply have a gauge at the base of the spray gun, and if your gun "requires" 15scfm, the as long as the pressure is above the "Called for pressure", then you know you are getting it based on the tool's specs???

I'll put up the pics of my actual tomorrow with a couple of formal questions. Just so until I get them, maybe someone knows where the formal Craftsman model number is or has used this compressor before?

These are demonstration pics only of the same unit listed on line in past auction somewhere.

Compressor Rrear.jpg

I've actually located a manual online I can't believe its like 30 years old it looks like the manual is dated 1989... It looks like a #919.176850

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PostPosted: Sat May 27, 2023 8:15 pm
In one of your earlier posts I responded to some questions you had and specifically said that you should be looking at a compressor with a capacity of 3-4cfm more than your gun uses and suggested 17cfm as a starting point. I also listed some different types of guns and suggested that you not use HVLP.

Why would you then go out and buy a compressor that is clearly going to not do the job and then talk about using an HVLP gun?

More than happy to help and will answer questions with as much detail as I can reasonably give, but after having done only about 8000 cars I do acknowledge that there are others out there who have more experience and/or specific knowledge than I do and accept that I can learn something new every day and willing to defer to someone with more knowledge than I.

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PostPosted: Mon May 29, 2023 8:46 am
12.2@ 40psi is similar to my 6hp 33g craftsman.Mines a bit newer and is oil less.
Runs my siphon feed gun but I haven't painted a whole car only parts of it.

I did check the net to see what cfm that would be at 25 psi,the math is quite complicated so I gave up.Perhaps theres a chart?

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PostPosted: Mon May 29, 2023 10:00 am
Craftsman 5HP 33gal 125 psi 12.2 scfm@40 and 10scfm@90psi

The output of your compressor is going to be less than the 10cfm@90,
the compressor is always pumping against the tank pressure which is going to be
above 90 psi. so that's the refill rate.
Any other psi rating is totally irrelevant unless you have a really low tank pressure.

(It's not custom painting-it's custom sanding)

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