Question about air compressor mods?

[TopCatGr58]

Hey all,

I've got this little 4gal 125psi pancake oil lubed 1-3/4hp compressor. Occasionally I try to use some air tools that I selected with the least amount of CFM ratings I could find, but my tank just runs out of volume much faster than I want!

I've been looking at extra tanks, but the ones I've found even at 10 gal capacity are designed as portable units, with just a schraeder valve for filling and use!

Does anyone know whether I could attach some of the air hose type fittings and such, so that I could attach it to my 4 gal tank and use both together, and have the air tools fittings on the other end?

I got the other unit for $$ reasons, and not realizing that I would need such volumes for even my simple tools!
TIA!
T.C.

[Ken Talbot]

You could do it, TC, and it really wouldn't matter much where you take the air off. Logically, it will take that much longer to get the system charged, and when the pressure drops and the compressor kicks in, it will take longer to recharge.

Depending how much delivery you need, and for how long, you'll need to consider a second unit.

[sixtysix]

Some people use PVC to pipe air systems, just put in a few big hunks of sewer pipe of something, to increase volume, as Ken said, gains are short lived.

[Jerry]

Been a couple years...

I once bought an adapter for an LP tank (40 lb) to convert it into a storage canister for my little-bitty compressor. Adapter was brass, was kind of a "T" fitting, one side came in from compressor and other went out to air tool. LP tank could then double as a portable tank; I put quick-connects on both ports. Ran a lot of air in and out of the tank to purge it before I used is as an air source, including blowing the tank with it upside-down. However, it worked fine.

Was a little heavy for portable work, so I bought a Sears 5 gallon portable tank a few years back. Put quick-connect fittings and a "T" on it, same set-up as the older tank with the advantage that the Sears unit has an on-off valve gong into the tank so it won't leak down over periods of non-use. Smaller than the LP setup but a lot easier to move around, and it has a pressure gauge on it.

Considering my compressor is a home built consisting of a 1/2 hp motor and an old York AC compressor out of an old Chevy I needed something for a reserve tank. Photos are at:
http://facstaff.uww.edu/fieldsj/mcycle/Comp/
Original tank shown in these photos was replaced by the LP tank, idea is the same. Original rusted out after a few years use; I should have put a drain valve in it.

Ken has the right of it, if you need more volume for short bursts then then the tank will help. If you need it for longer runs, like using an air sander for more than a few minutes then get a bigger compressor. I use mine for impact wrench and air hammer for the most part. Keep the compressor hooked up as well as the line to the air tool, seems to work out OK for my use.

[79XS11F]

Air tools do in deed suck up the air quickly. As was stated a bigger purge tank will last longer but also take longer to fill so in the end the down time is about the same. Purge tanks do work well when they are large and are filled to a higher pressure then the tool needs. You will likely find yourself needing a bigger compressor. I ran into the same issue when I got my first compressor and realized that it was too small for my needs as my needs grew.
Rob

[LoserShoes]

Yep, my first compressor was too small, hated the sitting there waiting for the air to come back up. This time I went and bought a 6.5 hp two stage like you see in Home Depot etc. Haven't regretted the expense once since then. Runs my sand blaster continuously.

Steve

[eroellig]

Re: Question about air compressor mods?

Originally posted by TopCatGr58
Hey all,

[...]
Does anyone know whether I could attach some of the air hose type fittings and such, so that I could attach it to my 4 gal tank and use both together, and have the air tools fittings on the other end?

I got the other unit for $$ reasons, and not realizing that I would need such volumes for even my simple tools!
TIA!
T.C.

Hey, TC...

Yeah, I've done it also. I use a few air tools for my RV. I got a portable compressor, but sized it so that my generator will run it. (translation, its a small compressor) I got a portable 7 gallon tank and added fittings & valves so that I can attach the compressor to the out-board tank, then a regular quick connect to attach air hose. Works OK for short burst activity.

Eric

[Hammerhead1st]

Ok here's my take...

As many of you know, I'm a tinker-er without the budget required for tinkering. Therefore, I find invention to be 2nd nature to me at home. Whatever I can't buy, I make. Whatever I can't make, I have someone steal.

Here's my solution, however lame it may be. It works for me, so :

You have a pancake compressor. SO do I. It shuts off at 135 PSI. I also have a combination battery charger/air compressor built from a 1/2 hp motor, a Chevy alternator, and an old a/c compressor from God knows what type of car. Simple v-belts run the alternator AND the compressor as I choose.

I feed the air from the compressor into the tank I have from an old compressor that no longer worked. Remove the hardware, and I have a portable tank on wheels that holds over 160 PSI easy. Now, what I did was to run the air line from the a/c unit to the tank input. On that input, I installed a T-valve with a shutoff to keep air in the tank when no tools are connected. On the other end of that T-valve, I put a quick connect for the air line going out.

On the other end of the tank, I installed an air chuck quick connect and use that for the pancake compressor unit. Both units feed the tank, and i draw out of the tank itself instead of from the compressors. BOth units working in tandem keep me in relatively good shape as far as pressure is concerned. I still can't run a sander for too long without allowing the tank to catch up, but I did add about 5 minutes of sanding time to the 2 minutes I had before.

Hope that helps from a low-budget standpoint...

[TopCatGr58]

Thanks to everyone for their ideas/info!

Hey folks,

Well, I went to Harbor Freight today and picked up the 10 gal port. tank, along with a short 160PSI rubber hose, a new decent filter/oiler set, and then went to Lowes for the required 1/2" to 1/4" Npt fittings, T fitting, pipe section, and then came home and put it all together! I had a spare regulator from the pancake that I put on the spare tank so that I could disconnect and use as portable if so desired, used a quick connect for the rubber junction hose, and fired it up.

I also picked up a mini die grinder set, and diamond embedded grinder bits set. Tod/Trbig told me about how JOHN used one and was able to grind the flat slots on the 1st gear wheel very quickly vs. a Dremmel! So...since I'll be doing that on a couple of more machines I have to work on in the future, thought I'd try it!
Thanks again for the help!
T.C.

[Hammerhead1st]

Thats the exact compressor I have as well.

Hope it works out for you. Let us know! Your tank is roughly the size of mine, but I believe mine's a 15gal. The compressor couldnt keep up, so I added the other one to the mix.

[John]

Die grinder.

That's all he'll need for the trans repair, as you won't have the tool running flat out anyway. The compressor will be able to keep up the demand. Wildkat used one of those very same compressors whe she painted the FJ11.
Make sure you use the cylindrical tool on the trans. You can control the angle of the cut better. Just keep measuring the slots and dogs and keep them the same size.

[wa407mpp]

ac compressors.

AC compressors are designed to work in a closed system and allow the oil to circulate through the system and back to the compressor ,or they use a oil separator. Keep a eye on your oil level or you will burn up your compressor. I have heard that the GM rotorarys dont have this problem, but I have'nt tried one. You can hook two regular air compressors with separate tanks in series ,as a two stage system,with a bigger tank on the second one and running at a higher pressure. That way it doesn't take as long to refill the second tank. but if you don't already have two compressors and tanks you won't save any money over buying a new larger unit .Warning!! Before you buy a new system make sure you can run it with out rewireing your shop ,they come in both 220 volts single and double phaze.

[wa407mpp]

check valve

I forgot to tell you to use a check valve between the first tank outlet and the intake of the second compressor,this may not work on some compressors .

[Ken Talbot]

Re: ac compressors.

Originally posted by wa407mpp
Warning!! Before you buy a new system make sure you can run it with out rewireing your shop ,they come in both 220 volts single and double phaze.

Sounds familiar. A few years back, SWMBO's brother the mechanic was upgrading the compressor in his shop. He gave me his old compressor for free so now I've got my little portable unit plus his cast-off, a nice little two cylinder, belt drive unit that works really well for sandblasting and just abut anything else I've tried. Of course, it only cost me about six hundred bucks to install a small sub-panel in the house so I could run a 220v service out to the carport. Still, that was still cheaper than having to spend that much again on a compressor.

[fredintoon]

more CFM

Hi TC,
the important number for air compressors is the CFM. If your air tool wants more CFM than your compressor puts out you eventually gonna run out of air. A bigger air tank will of course hold a larger reserve but that only delays the inevitable. But you knew that. An extra tank, or a whole bunch of them, can be added. Over-age propane tanks can be found at the dump at no cost. Just thread the valve out and fit a tee connection.