Compressor Size

[JohnInReno]

I have to replace my aged 2.5 hp compressor before I start this RV project. The biggest 110 volt I have found is 5.0 hp (1.8 sustained) 30 gal tank with an oil type, belt driven, compressor. Lowe's Kobalt house brand. Will this be adequate for riveting?

TIA
john

[R.P.Ping]

That should be just fine. I had a 5hp dry pump compressor that I replaced with a 5hp wet pump and what a difference. They were both rated about the same but the wet pump only runs about 1/3 as much and is MUCH quieter.

[atreff]

John,

It's best to go by CFM (cubic feet per minute), not HP. Not all pumps that require a 5HP motor are the same. Check the output at 90 PSI, which is where I run my drills and die grinders.

I have been using a 2 cyl 5HP wet pump compressor with 25 gallon tank, rated at 6.4CFM @90 PSI. It is fine for riveting and most drilling. While drilling wing skins I was operating that drill continuously, and eventually the RPM would slow, and the compressor ran most of the time. This was not a problem, as the pump is cast iron and is built for it, but I don't like slowing down to wait for the compressor to catch up.

What makes the compressor run is how many CFM your tools draw. Cheap drills will suck tons of air, as do blow guns, conventional spray guns, DA sanders, bead blasters and die grinders. Is my 6CFM enough? OK for riveting, and adequate for drilling if you don't mind waiting. But, When dressing parts with a die grinder and scotch brite disks, 6CFM was not enough, the grinder would lose RPM, and I'd have to wait for the compressor to fill the tank. the Pump also got pretty hot.

Also, I've been spraying furniture with Lacquer in a cheap automotive paint gun, and here too, during a long session, I'd have to stop painting to wait for the compressor to catch up. In hindsight, I wish I had spent a tad more and gone with one that would put out above 12 CFM at 90 PSI, which is what most of my sanding and grinding tools need.

I'm now building a new shop and upgrading my compressor to a vertical tank model, that'll do 14CFM at 110 PSI. I got tired of the compressor running all the time, and I'd like to run a bead blaster. This will be the last compressor I have to buy, cause it'll run anything I hook up to it. Northern Tool has many good compressors on sale with free shipping right now.

Another tip, If you can put your compressor in another room, or mount it outside, that would help to lessen the noise.

Art in Asheville
RV-8 finishing

[DGlaeser]

Originally Posted by JohnInReno

I have to replace my aged 2.5 hp compressor before I start this RV project. The biggest 110 volt I have found is 5.0 hp (1.8 sustained) 30 gal tank with an oil type, belt driven, compressor. Lowe's Kobalt house brand. Will this be adequate for riveting?

TIA
john

I have that exact same compressor. I riveted my empennage with no problem at all - compressor doesn't run much at all. I set the adjustable guage for about 40-45 psi to drive the 3/32 rivets and still used a light touch on the trigger. I have a pneumatic squeezer - used mostly for dimpling at 100 psi. Compressor runs a bit more of course, but still not all that often. I don't use an air drill, but that may use more air. Painting will be the real test. My son has a Sears oilless (noisy) 5hp/30gal and he just started painting his interior with an HVLP sprayer (from Lowes) and has had no problems, so I expect we'll be just fine.

Dennis Glaeser
7A Empennage done - Wings come next week!

[N797RV]

I have a 5hp oil compressor with a 33 gal tank the only thing I would have done diffrently is to get a vertical tank. They take up less realestate in the garage and it easier to drain.

Dick
N797RV reserved
RV-7A finish kt canopy skirts

[mlw450802]

Originally Posted by JohnInReno

I have to replace my aged 2.5 hp compressor before I start this RV project. The biggest 110 volt I have found is 5.0 hp (1.8 sustained) 30 gal tank with an oil type, belt driven, compressor. Lowe's Kobalt house brand. Will this be adequate for riveting?

TIA
john

I'd reccommend waiting to see if your compressor is actually inadequate for the job before rushing out to spend the money on something bigger (unless, of course, it's a case of "I just want a new compressor").
I was in the same boat as you prior to starting my kit (I had a 6 gallon Porter Cable compressor designed for nail guns) and agonized over what size machine I should get, because I thought my compressor would be too small.
I decided to just see if that would be the case and I have now finished my empennage and am three quarters through the wings and haven't needed anything larger yet.
I'm sure (I think) it will not paint the entire plane but it seems happy enough for all the riveting, drilling, squeezing and dusting chores I have asked of it to date. Plus it takes up almost no space and that is a premium for me.