90, 135, 175 ??? What PSI do I need?

[OkeeDon]

I used to have a 10 HP, 3 phase, two-stage compressor that would output around 20 CFM @ 175 psi and over 25 CFM @ 100 psi. I used it to run a fiberglass chopper gun that used every bit of the volume and pressure with an air-powered pump for the resin, pressurized container for the MEK, a high speed air knife to chop the fiberglass strand, and air pressure at the nozzle to blow it all at the mold. It had a 100 gallon tank, and I never ran out of air.

Today, I have a 5 HP unit from Sam's Club that works fine for everything - air tools, impact wrench, paint sprayer, etc., except that I can generally only run one tool at a time. I suspect you'll be happy with the less expensive unit unless you have a compelling need to be the baddest guy on the block -- and I bet someone will have a bigger one.

 

[Junkman]

I would suggest getting the largest tank that you possibly can.. more air for the times when you need it. A vertical tank takes less room than a horizontal one. When I had my shop, I had 3 80 gallon tanks hooked together to get the volume needed. The difference in cost between the 60 and the 80 isn't that much... Also, check on e Bay for a used one... I have seen some good buys on quality units because they were 3 phase. The cost of changing the motor was very little compared to the cost of the same single phase unit. I only with that e Bay was around 10 years ago when I bought my unit.. Would have saved a bundle and had a bigger unit than I purchased for the same money.

 

[Libertine]

Henro:
In addition to some of the other suggestions, you might (if it's of any value to you) consider the construction. It's not simply a matter of psi, cfm etc., but how long it might last. Can the compressor be rebuilt? Does it use oil or is it one of the new "oil less" types. How is it driven i.e. is there a belt between the power source (electric motor) and the compressor itself, or is it direct drive. I have seen both brands you mentioned and they appear (at least to my untutored eye) to be decent quality. Ingersoll Rand makes some real professional stuff and the Campbell seems pretty decent too (they claim made in US if memory hasn't failed). I was looking for something myself recently and ended up with a (blush blush) Craftsman since they were selling a decent sized upright on wheels for less than $300. If I'm lucky it will last through my twilight years.
JEH

 

[slowrev]

Henro,
As someone else said do not get one of the oilless types. VERY noisy and fairly short lived. I know because my wife got me one as a gift. Works ok, but I had to put in the outside woodshed on the other end of my shop and run an airline from there. Still loud, but tolerable now.

Also get a good impact gun, not one of the cheap ones. I recommend Ingersol Rand. They have a couple of models that will run close to 600 lbs of torque in a 1/2 inch gun, for about $150.00.

 

[RobertN]

Watch out for the oilless versions. They are less expensive, but most are loud! Mine works fine(DeVilbis PRO-4000 5hp, 60gal, 10.3cfm@90psi), but man, you need earplugs when it runs. There was talk about this about a year or so ago. They are not built for heavy use(not all, but a large majority).

Bird could tell more about the advantages of a cast iron cylinder type compared to the oilless.

If and when I get another, I will go back to the cast iron oil bath type.

 

[BIGUN]

Read all the opinions on air compressors voiced here a few months ago. Air Compressors

 

[Henro]

Hi again,

Sure is nice to have a place to go to get good advice!

At first I was thinking of a 175 psi IR compressor from Northern Tool [free delivery, no tax probably, did not check]...

This one...

But now I have come to my senses, and for my needs I think I will buy this one from Harbor Freight...Campbell Hausfeld brand and costs $429. Campbell Hausfeld VT-6275.

(I had a link here but it stopped working after I copied and pasted the following)

It is listed as:

Large capacity ASME tanks are designed for running more than one air tool. Solid cast iron twin cylinder pumps offer years of trouble free operation. U.L. listed
Horse Power: 7
Stage: single
Power supply: 230V
Amp draw: 15
Maximum pressure: 135 PSI
Air Delivery:
@ 40 PSI: 11.8 SCFM
@ 90 PSI: 10.3 SCFM

Number of cylinders: 2
Lubrication: oil
Tank configuration: vertical
Tank size: 60 gallon
Shipping weight: 290 lbs.
Campbell Hausfeld VT-6275

Free delivery and no sales tax are pushing me towards the purchase from HF. I think the quality of this product will be the same wherever I buy it from, so I am not too worried about HF being the source.

Guess I will be ordering it in a couple days unless someone here knows something negative about it that I don't see.

Should do what I need it to, I suppose. 135 psi should give me a little more air tool torque than I am used to... /forums/images/graemlins/cool.gif

As always, thanks for the help! /forums/images/graemlins/smile.gif

 

[BIGUN]

</font><font color="blue" class="small">( Free delivery and no sales tax are pushing me towards the purchase from HF. )</font>

This hit a nerve. After just recently moving to OK from TX I feel like I am being taxed to death. On top of every tax Texas has, we also have sales tax on groceries, medication, roads (tolls everywhere), and income tax. And to pour salt in the wound we also have “use tax” with a place right on the state income tax form to add that on, as if we have not paid enough already. Oh, if you can’t remember what all you ordered from out of state they charitably offer to just let you pay an additional flat percentage of your already over-taxed income. /forums/images/graemlins/mad.gif
Have to keep reminding myself a good paying over-taxed job here beats no job in Texas.
I feel better now. /forums/images/graemlins/wink.gif

 

[Egon]

Henro:

Sounds like a good choice.

Egon

 

[Bird]

Bill, the link you provided for that Campbell-Hausfeld says "Sorry, the item number is not a valid item." /forums/images/graemlins/confused.gif Now in looking at all their compressors (94 of them), I find they also sell this Puma which is what I had. I sure don't want to tell you to buy any specific brand or model because you might not have the same luck that I had, but I bought the Puma over Campbell-Hausfeld myself for several reasons. I got my Puma from a business that specializes in air compressors and even build some of their own, and the Puma was their recommendation for that price range. They said they had some of that same model in commercial use that were used 18 hours a day and never required any repairs. Some compressors tend to vibrate enough that they "walk" around in the shop. My Puma never moved at all. The Puma has V-twin cylinders instead of inline vertical (now I can't prove one is better than the other, but it seems to me the V-twin should cool better if run a long time). The Puma has better air filters on the intake (same type of filters you find in lots of cars). Another thing I can't say for sure, but I think the Puma has a deeper oil sump for better lubrication. I've had a small (1 hp) portable Campbell-Hausfeld and couldn't complain about them, but my Puma was run nearly every day, sometimes for extended periods of time for several years and the only I ever did to it was drain the water out of the tank frequently, changed oil in it once, never needed to add any (it had a sight glass to check the level), and when I sold the farm, I sold the compressor for $100 less than it cost me new.

So we're talking about my personal preference; your mileage may vary. /forums/images/graemlins/wink.gif /forums/images/graemlins/laugh.gif