Need pump help!!!!!!

[eli_ess]

Hi guys,

As you can see, I'm brand new here.

I have built two air guns so far- one made of PVC (which can take up to about 80 PSI) and my newest one- which is made of galvanised steel pipe.

The problem with my brand new pipe-cannon is the PSI ! I can get it up to about 280 PSI with my stand-pump (designed for mountain bikes, so comes with a higher PSI limit than a regular bike pump), but basically I can't physically get any more air in it. My arms just can't push it any further than that.

The cannon itself can take more, I think... (it doesn't seem to be leaking air).

So is there another pump option? I'm so new to this, so perhaps there is another type of pump I can use, which doesn't involve me physically pushing air into it? I have an air compressor for my car tyres, but it has a limit of 300 PSI, which is basically what I can do by hand.

Ideally I'd like it to get to about 400 PSI.

If anyone has ANY suggestions, I would really appreciate it. I love the forum- have been browsing for a while now!

Cheers,

Eli.

[mark.f]

Ideally I'd like it to get to about 400 PSI.

This is perfect for a modified refrigerant compressor like that found in a refrigerator or small air conditioner.

The process is different for different equipment and brands, but it's pretty simple. Short the temperature sensor so the compressor runs all the time, and then basically transfer it, the wiring, and the typical AC start/run capacitor out of the unit. Add a high pressure hose from the high pressure side of the compressor and add a small filter (can be as simple as zip-tying a piece of foam over the tubing) to the inlet.

You can wire a switch inline with MAINS power to the compressor, or simply plug/unplug the compressor to turn it off and on. MAKE SURE to use safe wiring methods (I used cheap wire nuts and plenty of electrical tape for mine) and consider the possibility of adding a GFCI breaker in somewhere in addition to the switch, if you don't plan on using GFCI outlets. The air conditioner I tore mine out of came with a plug with built in GFCI breaker and I used the set/reset buttons to turn power on the compressor.

Humidity and debris can kill a compressor like this fairly quickly, but mine has been running for a good couple of years now with intermittent use up to 500 PSI, and I lived in an area with 100% humidity pretty much year round.

Good luck with your endeavours!

EDIT: finer points.

[eli_ess]

Thank you, I really, really appreciate your reply!

[wdr0]

Not trying to discount what mark said, but I would recommend against using the gfci as a switch. They do wear out and using it in that manor could make it in effective. I realize it's use would be sporadic but best not to as a general practice.

[mark.f]

Not trying to discount what mark said, but I would recommend against using the gfci as a switch. They do wear out and using it in that manor could make it in effective. I realize it's use would be sporadic but best not to as a general practice.

True, true. I would recommend wiring a separate switch and not using the breaker for switching power to the compressor. I just used what I had.

EDIT: Ah, I see what I did. I added "in addition" to that sentence. Thanks wdr0.