Van's Air Force
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What size air compressor did you use?
- Thread starter flyabq
- Start date
fixnflyguy
Well Known Member
Depends...
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.
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
Well Known Member
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
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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
maniago
Well Known Member
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.
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.
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pazmanyflyer
Well Known Member
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.
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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
Well Known Member
After research
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.
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.
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.
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.
Jeremy,
I did a quite a bit of research and thinking before selecting a compressor for my RV-10 build. Like most things in life and building there are trade offs and so no single right answer.
When it comes to compressor size there are 2 key measures of size. The first is the compressor (air pump) output, measured in standard cubic feet per minute (cfm) at working pressure. Typically 90 psi pressure is used for rating air compressors for our use. If you have a compressor with an output that is equal or a bit higher than the air volume used by your tool, your air tank can be very small without impacting your work.
The second key measure however is tank size. The tank stores the air and allows the compressor to cycle on and off rather than run continuously. Since most tools we use only draw air for short periods of time (from a few seconds for a rivet puller or squeezer to a few minutes for an air drill), a large tank can provide the air at higher volume than the compressor can produce for a period of time, allowing a smaller compressor to support your work. But when you require a high volume of air for an extended time period as required for a spray paint gun, the stored air in the tank will run out before you have completed the task, requiring you to stop and wait for the compressor to catch up by refilling the tank.
So you are looking for a balance between compressor size and tank size. But compressor price increases with larger capacity, and the power required increases driving a change to higher voltages and amps, and then to 3 phase power in industrial size compressors. And as tanks get larger, weight goes up, portability goes down, and price goes up. Higher operating/storage pressure is another factor that can help storage volumes but also drives up cost, weight, power, etc.
Another factor worth considering is noise. Belt driven, lower speed, oil lubricated compressors tend to be less noisy and longer life than direct drive non-lubricated compressors, but these also cost more. So unless you can place the compressor in a different location or sound attenuating enclosure, noise (measured in dB where a higher dB is a louder machine, and every 3 dB increase doubles the noise level) is also a selection consideration.
So what is the electrical capacity in your shop, how much space do you have for the compressor, how much noise can you accept, how much money do you want to spend, do you want to be able to move the compressor without a crane or pallet jack, do you want to do high volume painting, etc. are a few of the considerations.
For my shop, after weighing all these considerations including reliability, longevity, availability (what compressors are available for purchase), etc, I ended up buying a Quincy 26 gallon, 7.4 SCFM at 90 psi, portable electric vertical compressor. This was the highest capacity I found that would run on a 120 VAC, 20 amp circuit, had wheels and so could be moved without tools, could be re-wired for 220 VAC in the future if I wanted to do so, was oil lubed, belt drive and so relatively quiet, assembled in the USA with a good reputation for reliability and reasonable quality.
I bought mine from Lowes https://www.lowes.com/pd/Quincy-Com...ble-Electric-Vertical-Air-Compressor/50073349 as they were in stock and lower price when I bought mine a couple of years ago.
I have been very happy so far with my selected compressor. I have been able to do some painting, including primer and painted the interior of the cabin. I plan to have the exterior professionally painted, so don’t need a larger compressor and paint booth. I only moved it around my shop a couple of times, preferring to leave it in one place next to a power plug and using a long hose instead. I was pleasantly surprised to find that it worked well on a 120 VAC, 20 amp circuit that also has some lights on it, so I didn’t need to run a separate circuit or convert it to 220 Volts. So for my purposes, I would give it a full 5 star rating.
Sorry for the long dissertation, but I find that a lot of people don’t fully understand the air compressor sizing and compressed air physics that impact the selection and satisfaction, and often just look at the air tank capacity. Hope something in this post is helpful.
I did a quite a bit of research and thinking before selecting a compressor for my RV-10 build. Like most things in life and building there are trade offs and so no single right answer.
When it comes to compressor size there are 2 key measures of size. The first is the compressor (air pump) output, measured in standard cubic feet per minute (cfm) at working pressure. Typically 90 psi pressure is used for rating air compressors for our use. If you have a compressor with an output that is equal or a bit higher than the air volume used by your tool, your air tank can be very small without impacting your work.
The second key measure however is tank size. The tank stores the air and allows the compressor to cycle on and off rather than run continuously. Since most tools we use only draw air for short periods of time (from a few seconds for a rivet puller or squeezer to a few minutes for an air drill), a large tank can provide the air at higher volume than the compressor can produce for a period of time, allowing a smaller compressor to support your work. But when you require a high volume of air for an extended time period as required for a spray paint gun, the stored air in the tank will run out before you have completed the task, requiring you to stop and wait for the compressor to catch up by refilling the tank.
So you are looking for a balance between compressor size and tank size. But compressor price increases with larger capacity, and the power required increases driving a change to higher voltages and amps, and then to 3 phase power in industrial size compressors. And as tanks get larger, weight goes up, portability goes down, and price goes up. Higher operating/storage pressure is another factor that can help storage volumes but also drives up cost, weight, power, etc.
Another factor worth considering is noise. Belt driven, lower speed, oil lubricated compressors tend to be less noisy and longer life than direct drive non-lubricated compressors, but these also cost more. So unless you can place the compressor in a different location or sound attenuating enclosure, noise (measured in dB where a higher dB is a louder machine, and every 3 dB increase doubles the noise level) is also a selection consideration.
So what is the electrical capacity in your shop, how much space do you have for the compressor, how much noise can you accept, how much money do you want to spend, do you want to be able to move the compressor without a crane or pallet jack, do you want to do high volume painting, etc. are a few of the considerations.
For my shop, after weighing all these considerations including reliability, longevity, availability (what compressors are available for purchase), etc, I ended up buying a Quincy 26 gallon, 7.4 SCFM at 90 psi, portable electric vertical compressor. This was the highest capacity I found that would run on a 120 VAC, 20 amp circuit, had wheels and so could be moved without tools, could be re-wired for 220 VAC in the future if I wanted to do so, was oil lubed, belt drive and so relatively quiet, assembled in the USA with a good reputation for reliability and reasonable quality.
I bought mine from Lowes https://www.lowes.com/pd/Quincy-Com...ble-Electric-Vertical-Air-Compressor/50073349 as they were in stock and lower price when I bought mine a couple of years ago.
I have been very happy so far with my selected compressor. I have been able to do some painting, including primer and painted the interior of the cabin. I plan to have the exterior professionally painted, so don’t need a larger compressor and paint booth. I only moved it around my shop a couple of times, preferring to leave it in one place next to a power plug and using a long hose instead. I was pleasantly surprised to find that it worked well on a 120 VAC, 20 amp circuit that also has some lights on it, so I didn’t need to run a separate circuit or convert it to 220 Volts. So for my purposes, I would give it a full 5 star rating.
Sorry for the long dissertation, but I find that a lot of people don’t fully understand the air compressor sizing and compressed air physics that impact the selection and satisfaction, and often just look at the air tank capacity. Hope something in this post is helpful.
flyabq
Active Member
Thank you
Thank you for your input. I am looking along the lines that you are talking about. I appreciate you taking the time to respond.
Thank you for your input. I am looking along the lines that you are talking about. I appreciate you taking the time to respond.
The HF compressor I started with was incredibly noisy, I had to wear hearing protection whenever it was running. I wound up with a California air tools 6gal model which advertised 60db. Don't know about the 60 db, but it's about as loud as a washing machine. You can have a normal conversation standing next to it. no problem with capacity, but I used an air brush with Stewart Systems eko prime to prime the surfaces..takes a bit longer, but not much, no cleanup, no toxic fumes, no paint booth....just toss the airbrush into some water 'till next time.
https://www.homedepot.com/p/Califor...-and-Oil-Free-Air-Compressor-5510SE/205602927
https://www.homedepot.com/p/Califor...-and-Oil-Free-Air-Compressor-5510SE/205602927
dave4754
Well Known Member
Budget = Auction for me
I purchased a 60 Gallon 5 hp at auction for 200 Cdn. Surprise it worked? Got lucky i guess but they are out there.
For any amount of painting, air sanding, air drill work the smaller ones just dont cut it.
I did build most of my 7 with a small 20 gallon and it will do but you have to wait for it after heavy use of air drill or die grinder which you use alot.
I agree with the other responder, wait till the bills for the rest of the airplane come in.... this will seem like peanuts!
Dave
I purchased a 60 Gallon 5 hp at auction for 200 Cdn. Surprise it worked? Got lucky i guess but they are out there.
For any amount of painting, air sanding, air drill work the smaller ones just dont cut it.
I did build most of my 7 with a small 20 gallon and it will do but you have to wait for it after heavy use of air drill or die grinder which you use alot.
I agree with the other responder, wait till the bills for the rest of the airplane come in.... this will seem like peanuts!
Dave
Draker
Well Known Member
Don't forget about sound output! I originally got a 20 gallon Home Depot special, which worked, but was so loud in my small garage I felt like I'd get hearing loss if I forgot my ear plugs. About when I started my wing kit, I replaced that with a 10 gallon California Air Tools compressor, which ended up being much quieter. No hearing protection needed, in fact, sometimes I forget to leave it on, it tops up in the middle of the night, and nobody in the house hears it! The 10 gallon tank is small but sufficient. Honestly I think anything over 20 gallons or so would be overkill for RV building. I currently have a 5 gallon external tank in the system to add a little extra capacity, but even the 10 gal on its own is enough.
But also don't forget about air volume as well: Be aware the California Air Tools is much quieter because it's much less powerful. I've never used it but I'd have to imagine it cant keep up with an air drill or die grinder used with any frequency with only 2.2 CFM; adding tanks would run less but would take a long time to recharge. Maybe some users of the california air tools could chime in if they use an air powered drill or die grinder, do you frequently have to wait for the compressor to catch up?
Per their stats:
California Air Tools 3.10 CFM / 40 PSI and 2.20 CFM / 90 PSI
Harbor Freight 5.8 CFM @ 40 PSI, 4.7 CFM @ 90 PSI
some commonly used tools with high air demands in CFM:
Die Grinder 1/4" 4 - 6
Drill, Reversible or Straight-Line 3 - 6
Draker
Well Known Member
Chris,
The California Air Tools compressor I have is model # 10020C, with the following specifications:
6.40 CFM @ 40 PSI
5.30 CFM @ 90 PSI
I just finished up my wings and so far, I have found its performance satisfactory for drilling and squeezing rivets, and adequate for my die grinder and HVLP spray gun. It cycles pretty frequently while spraying primer and cannot keep up with sustained spraying, so I work in short bursts. Otherwise I'm happy with the setup.
The California Air Tools compressor I have is model # 10020C, with the following specifications:
6.40 CFM @ 40 PSI
5.30 CFM @ 90 PSI
I just finished up my wings and so far, I have found its performance satisfactory for drilling and squeezing rivets, and adequate for my die grinder and HVLP spray gun. It cycles pretty frequently while spraying primer and cannot keep up with sustained spraying, so I work in short bursts. Otherwise I'm happy with the setup.
I too went with the 26 gal harbor freight special. I have had it for about a year now maybe a little more and have already had to replace the reeds in it. Now don't get me wrong, this compressor will most definitely do the job but it is freaking loud and runs a lot. I sincerely regret quite often not spending the extra money and buying a 60 gal unit. Before I build my next plane (which will be a -10) I will definitely purchase a 60 gal model. I even have this one book marked. 
