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Pneumatic gun air pump conversion

Jon305

Member
Jan 21, 2020
46
10
23
Hi, has anyone tried converting the original hand pump into one that can be connected to high pressure air or at least a better hand pump? I was thinking of trying something like this and maybe T'ing off a pressure gauge, do you think it would work? I think ive seen a post on this topic before but i couldn't find it again
 

burjegol

Well-Known Member
Nov 6, 2005
26
5
93
64
Got tired of pumping my cyrano 90, removed the front fitting of the hand pump, brazed a1/4 flare union, connect to gage,then nitrogen tank. Presto!
Was intending to fit it to a scuba tank, but then,nitrogen is much better than air.
 
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popgun pete

Well-Known Member
Jul 30, 2008
4,251
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Jon305

Member
Jan 21, 2020
46
10
23
Thanks for the replies guys, i think ill fiddle with the hand pump and try something too or just find someone to machine me an adapter
 

marco15499

Laguneros Spearfishing
Apr 4, 2011
307
118
83
Even if I think that finding a better way to fill the pneumatic guns is cool, I don't see the need for it. In 6 years I only pumped my gun twice. If you don't mess around with your pneumatic speargun, It will last forever without any special mainteinance.
 
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stefpix

Well-Known Member
Aug 15, 2015
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You only need to pump the gun when you change the oil. It takes 15 minutes.
I wish the pumps were of a larger diameter and volume, like a bicycle pump, so probably;y it would take 50/100 strokes instead of 200/400.

If you travel by air and put your gun in the checked baggage, do you need to depressurize it? when I bought spearguns online they traveled by air and came already pressurized. I would see that as one of the few reasons for having to pressurize/depressurize a speargun
 
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vrokhlenko

Well-Known Member
Sep 22, 2002
250
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You only need to pump the gun when you change the oil. It takes 15 minutes.
I wish the pumps were of a larger diameter and volume, like a bicycle pump, so probably;y it would take 50/100 strokes instead of 200/400.

If you travel by air and put your gun in the checked baggage, do you need to depressurize it? when I bought spearguns online they traveled by air and came already pressurized. I would see that as one of the few reasons for having to pressurize/depressurize a speargun
Correct, you must depressurize your guns. I need 500 strokes to take it to the proper pressure. My pump is home-made since the original is shit. And no more oil use - pure silicone paste. Works way better and stays in place
 

marco15499

Laguneros Spearfishing
Apr 4, 2011
307
118
83
You "should" depressurize your guns. I've never done it. And never a problem. I have it at 26 BAR though.
 

stefpix

Well-Known Member
Aug 15, 2015
100
29
68
54
Correct, you must depressurize your guns. I need 500 strokes to take it to the proper pressure. My pump is home-made since the original is shit. And no more oil use - pure silicone paste. Works way better and stays in place
How did you make your pump? if I could use a large bicycle pump with gauge it would be faster.
 

Jon305

Member
Jan 21, 2020
46
10
23
The reason i want a better pump or adapter is because i had to repair mine twice, and i also depressurize the gun when winter comes around, its just a pain pumping 500 times so id much rather get a bike pump or machine an adapter, plus i take frequent flights to Miami and ive heard depressurizing it is necessary
 

Jon305

Member
Jan 21, 2020
46
10
23
I also want a pressure gauge so i figure with either a bike pump or adapter id be able to facilitate that
 

popgun pete

Well-Known Member
Jul 30, 2008
4,251
1,185
353
Pneumatic gun hand pumps are very simple. You need to be sure that the pump does not leak at the nose fitting if it has one. Pumps that screw in directly and have an open front that seals on the flat washer located in the rear of the gun don't have such problems, but you need to make sure the rubber washer is not damaged as over time the pump nose tends to cut the washer with repeated use. This can cause small leaks which mean you have to do a lot more pump strokes to achieve the same pressure in the gun.
 

marco15499

Laguneros Spearfishing
Apr 4, 2011
307
118
83
Bike pump style is what i should have said, i was actually looking at converting a paintball tank bike pump, theyre high pressure pumps
That would work. There's people that have done that with success. They changed the pressure gage and have an adapter made by a machine shop.

It is in Spanish, but you get the idea:

 

burjegol

Well-Known Member
Nov 6, 2005
26
5
93
64
As of the moment, I am on vacation. I will post the picture on the set up when I return.
 

Jon305

Member
Jan 21, 2020
46
10
23
That would work. There's people that have done that with success. They changed the pressure gage and have an adapter made by a machine shop.

It is in Spanish, but you get the idea:

Yeah thats what im thinking ill do, theres a machine shop near me ill probably contact when i get a pump for this little project, thanks for the link
 
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burjegol

Well-Known Member
Nov 6, 2005
26
5
93
64
As mentioned previously, here is my own conversion on my Cyrano 90 pneumatic.
I removed the end fitting of the supplied pneumatic pump, brazed a 1/4" flare fitting to accommodate the refrigeration tubing. the tank is filled with Nitrogen.
 

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