air compressor purchase opinion needed

[cbrown747]

I have looked at many threads on the air compressor specs, including vans. I am not thinking of doing any painting and I may not use an air drill so can a 12 gal oil lub, 125psi air compressor do the job of building an RV? I see one on sale the next couple of days for only $149 (craftsman).

[apkp777]

I used a $130 el cheapo (Black Cat) compressor to build mine. I also had a 20 gl air tank plumbed in parallel to increase the volume. Other than constant running, it did the job.

[aerhed]

It's the running time that'll make you crazy. I often do compression checks with someones little compressor on Annuals. Drives you nuts holding a prop blade forever while you wait for the noise to stop so you can hear what's happening in the engine. Also frustrating to have your die grinder fade out in the middle of a cut. I would shop by pump CFM & tank size. Motor size less important for light duty stuff. Even a cheap one will give you years of light duty.

[chrispratt]

Originally Posted by cbrown747

...I am not thinking of doing any painting and I may not use an air drill so can a 12 gal oil lub, 125psi air compressor do the job of building an RV? ...).

Can it? ... Yes.

Will you enjoy it? ... Probably not.

Depending on your time frame and patience you can use an electric drill to build an RV. The RV's, especially the "Quick Build" kits, do not require a lot of heavy drilling into big chunks of metal such as spars, so you don't necessarily need heavy equipment. (If you're building an RV-12 I'd think this would be especially true.)

If the cost of the compressor is an issue then I'll assume you're not going the "Quick Build" route, which means you'll be drilling a lot of holes. Not to mention all the riveting. A small 12 gal compressor will run constantly while drilling and most of these little buggers are pretty noisy. So consider fatigue factor. Plus with small compressors you can often feel the drill changing speeds and getting hot in your hand since the drill is using air faster than the compressor can refill the canister. This is bad for your drill, not to mention the round hole you're trying to make. Most of the air drills like to have 90 psi at the gun to maintain correct speed and the little compressors just can't keep up when doing a lot of work or drilling into a thick piece of aluminum.

I started my -8 project with a 20 gallon, 5 hp Craftsman compressor. It ran constantly, was extremely noisy and just drove me nuts. I frequently had to stop what I was doing and wait for the compressor to refill sufficiently so I could drill again. I finally bought an 80 gallon compressor and never regretted the decision. Though 80 gallons may be a bit of overkill, the compressor motor would run maybe once an evening to refill the tank. It was blessedly quiet the rest of the time.

Just my two cents but I say buy something larger, at least 60 gallons. Look around the classifieds for a used one -- I suspect there are builders out there who want to sell their compressor once finished their project.

To your original question -- yes you can use a small compressor. It's just a matter of what trade offs you're willing to make.

Chris

[diamond]

Originally Posted by chrispratt

Can it? ... Yes.


... Just my two cents but I say buy something larger, at least 60 gallons. Look around the classifieds for a used one -- I suspect there are builders out there who want to sell their compressor once finished their project.


Chris

If you have a Menards store in your area, they are having a great sale right now on the Sanborn 60 gal compressor. Price is $378 with rebate, Offer good through December 5.

[foka4]

I promise I don't work Makita, but I can't help putting in a plug for their MAC700. It's a small compressor like the ones you find at Menards or Harbor Freight, but MUCH quieter. It has a low rpm motor and compressor, so it makes more of a low purr than a loud annoying buzz. My shop is in my basement, and the MAC is barely audible upstairs. You can easily talk over it in a normal voice.

It keeps up with my air drill and riveters, and is portable enough to take to the hangar for annuals and compression checks, which it also does with ease.

I have an inexplicable affinity for air compressors, and this is one of my favorites. The only way to have a quieter compressor is to buy an old 60's
chugger or pony up for a big screw comprssor.

M

[terrye]

I have a Dayton 1.6 hp 20 gal compressor running on 120VAC. This was the largest portable compressor I could find that still ran on 120VAC as I didn't have access to 220VAC. I am quite happy with it. Of course you can't use an air die grinder constantly with it, but for drilling, riveting and even painting with an HVLP gun it is fine.

[Kyle Boatright]

Originally Posted by cbrown747

I have looked at many threads on the air compressor specs, including vans. I am not thinking of doing any painting and I may not use an air drill so can a 12 gal oil lub, 125psi air compressor do the job of building an RV? I see one on sale the next couple of days for only $149 (craftsman).

How many SCFM at 90 psi does it produce? If it is this one, it is undersized for the job: http://www.craftsman.com/shc/s/p_101...9&blockType=L9

The issue with compressors is that bigger is better (and more expensive). If you're on a budget and only plan to build one plane, a good compromise would be to buy the least expensive one that'll get the job done.

If you're buying one for the long haul (several planes, big shop aspirations, etc.) it is probably advisable to purchase a bigger one.

As a data point, I think I have the 20 gallon, 5 horse Craftsman compressor mentioned by Chris Pratt earlier in the thread. It got me through building and painting my airplane, but no doubt it was loud. For what it is worth, that compressor would probably be rated at 1.5 hp according to today's rating practices. I think this is today's equivalent: http://www.craftsman.com/shc/s/p_101...&blockType=L22

It would be adequate for the job. There is also a vertical tank model at the same price. I'll choose a vertical tank model the next time around - takes up less shop space, etc.

[Andy Hill]

In the UK, it must cost ?50K minimum to build an RV, so for you guys, $75K?

The one "tool" you will use from Day 1 to the last day (and beyond) is the compressor, and there is little to be gained by "upgrading" / having a spare etc. It will probably be in the same room / workshop as you.

My advice therefore would be, in this area, buy one with a decent spec in terms of noise / capacity / reliability. We spent ?450 on a quiet / good one, rather than ?100 on a cheapo, and well into the second RV, it was a great decision

Andy

[E. D. Eliot]

Do research the archives - it's all there for you to view and decide. My opinion may vary from most but I try to buy at or near the top of the line tools.

Don't get 'cheap' tools - you will regret that forever and may eventually replace all or most of them with better tools.

Sorry to say this but you can't afford a good quality air compressor and tools then maybe you should reevaluate your desire to 'build' an airplane. Maybe purchase one already 'built'.

In my opinion, aircraft ownership and/or construction is not a good place to cut corners.