What size air compressor did you use?

flyabq · #1 07-23-2018, 11:07 AM

Hello,
I am getting started on a RV7. My question is what size air compressor did you use and do you feel that it was large enough? I am trying to build the RV7 on a budget (not on the cheap just smart spending) saving more for engine and Avionics when I get there.

fixnflyguy · #2 07-23-2018, 11:21 AM

Since you are relatively new to the posts here, which are the greatest thing on earth to an RV'er, I'm sure you will see a wide range of response. Actually there are likely plenty in the forums already if you search. But to address your question, a couple factors besides budget. Shop size and 115 vs.220 available, can you tolerate noise well, and will you be painting with it. It is possible to build an RV with a relatively small (3-5 hp, 25 gal tank) ,as drilling and riveting require very little airflow. Plenty of cheap ones available to do the job. Hard to beat a 5 hp. ,60 gallon stand-up size for all around. If you have limited space, a little roll around is easy to keep out of the way. No need to spend a bunch if you aren't going to paint or run a sandblaster. Bigger the tank, the less it runs, and quieter it will be.

rv7charlie · #3 07-23-2018, 11:35 AM

I currently have a dual, 3 cylinder, 3 phase model with a tank big enough for a family to camp in. Nothing smaller will do.

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Now for the reality of what you actually *need*. I *built the entire airframe* with a borrowed oilless compressor (noisy) with about a 10 gallon tank. I just sat it up outside my work space. On the rare occasions that I needed to use an air grinder for extended periods (rare), I'd have to wait for the compressor to catch up. If I'd been painting with a traditional gun, it would have been a real pain, and might have affected the paint quality due to waiting. But for normal riveting and air drill work, I never had an issue with that small compressor.

My advice is that if the budget is tight, you can buy small and still build an award winning a/c. If the budget is more flexible (and you have the space + available 220V power), go a bit larger. One option is to monitor Craigslist for a locally available larger compressor at roughly the same cost as a smaller new one.

I love my monster, but the only reason I own it is that I bought it at auction, and it has enough wear that I'll likely have to replace the compressor head eventually.

Charlie

odens_14 · #4 07-23-2018, 11:58 AM

20 gal harbor freight special, I think it was $99 on sale in 2007. Never really wished for more, the only thing I could think of needing a bigger one for would be painting.

maniago · #5 07-23-2018, 01:00 PM

If the airplane is the only thing you'll ever use compressed air for, then yeah just a 20gal is fine. If you decided to paint, good paint gear, booth etc will be an investment and you can buy a bigger one then....many years down the road. I still have my 20 gal used Craftsman oiled 240v and it does some limited duty, but my bigger 240v ingersol 60gal is now the main stay, and pulls auto duty as well. But not required by any stretch of the imagination.

To be honest tho, youre saving a drop in the bucket on compressors compared to what youre gonna need for engine and avionics. The cost of that stuff will blow your mind.......and not in a good way either.

pazmanyflyer · #6 07-23-2018, 01:03 PM

Quote:

Originally Posted by flyabq

Hello,
I am getting started on a RV7. My question is what size air compressor did you use and do you feel that it was large enough? I am trying to build the RV7 on a budget (not on the cheap just smart spending) saving more for engine and Avionics when I get there.

I'm also building a 7. I have the vert. 60 gal. from Home Depot. It's 240V so wiring extra required and its stationary so it's not going anywhere without effort. It's at my house and I plan on it staying there. Always have. Now that was in 2006. Still going strong. Ask yourself if you are wanting something stationary and not moving or something mobile and easily plugged into a 120V outlet. If it's mobile the the 20-30gal/120v (plugin) versions are plenty for building the plane. You will notice it runs more often when you're using a die grinder or drill and not really up for a full paint session. Priming with it is not an issue.

Maxrate · #7 07-23-2018, 01:05 PM

Jeremy, I don?t know where Bella vista is but if it?s in a large metro area try Craig?s list. I found a retired gentleman that was selling his 60gal upright for 250$. If your on a budget, painting your plane will be something to think about. You?ll definitely need the volume for that part of the project.

PilotjohnS · #8 07-23-2018, 01:22 PM

After much research got 20 gal from home depot. I found out the HF were not that reliable. Couldnt be happier with my Home depot version. No problems for 3 yrs.

Floresb18 · #9 07-23-2018, 02:43 PM

I bought a 26 gal HF compressor for ~$150 and have been using it for the past few months. A bit louder than my Home depot compressor that gave out on me after 11 years of service but it doesn't run nearly as much and liking it thus far.

gasman · #10 07-23-2018, 02:59 PM

The best you can do with 120 volt is about 5 cfm with a two stage compressor. Buy one to start with. If later you need more cfm, purchase another one and add it to the system. When you are done, take one to the hangar.

As far as gallons..... all they mean is how often do you want to hear your compressor run. You can also add gallons to a system by just adding another tank anywhere in the system. Old propane tanks cleaned out with TSP can make a very good air tank. Set it up where you can drain the water out of the tank. A used propane tank that has all valves in place, and still has ANY amount of vapor pressure will most likely have no rust in the tank. So, if the outside looks good, it should be good inside. You will be able to inspect the inside with the valves out.

I find a shorter run time to be less aggravating as long as I can get the job done.