I need help with a Pnumatic

[carve daddy]

I am an avid spearfisher and use bands on all my guns. I have 2 old Pnumatics that were aquired some time ago. Neither of them are working and I have no info on them. One is a Beuchat 850 and one is a pistol sea tech? They look to be made alike. I have disassembled the 850 and replaced the O-rings and freed up the trigger. I put it back together but dont have any clue on fluid or how to service it. Any help? Thanks

 

[Whiskey]

Refrigeration compressor oils such as those having a viscosity of Sae 10-15 are fine. I use aviation grade hydraulic steering oil with a viscosity of 15 on my cressi-sub and mares guns and they work fine. Try searching online for manuals for your gun, I found both for cressi and mares online.

 

[carve daddy]

Thanks Whiskey I will search for a manual. I was told I have to use metric O rings when replacing them. I am tring to rebuild this old gun. Has any one ever used compressed air off the inflator hose??
Mike

 

[Whiskey]

Inflator hose air that comes off your second stage and will only give you about 100 psi. Most air guns use higher pressure to be effective so you still need to add more air and increase the pressure. The question is how much? This information is normally in the manual and the pressure information is related to the number of pumps (when using hand pump) or can be checked by using a gun pressure gauge. You can probably contact Beuchat directly and ask them for the information. The European guns do use metric sizes orings and many of the smaller orings (trigger pin and pump air valve) are the real critical ones to get. I measured mine (did some conversions between metric and imperial) and bought them on Amazon from a supplier called Small Parts, Inc. They work well and guns operate fine.

I do know a guy who has a filling system; pressure control valve that is attached to a dive tank (also has a pressure gauge) and he can control the pressure and fill his guns quickly to the desired pressure.

A handpump works fine if you can get your hands on one or adapt one to the threading sizes that your guns have.

Beauchat may have an oring kit set available.

 

[MARMIR]

I am an avid spearfisher and use bands on all my guns. I have 2 old Pnumatics that were aquired some time ago. Neither of them are working and I have no info on them. One is a Beuchat 850 and one is a pistol sea tech? They look to be made alike. I have disassembled the 850 and replaced the O-rings and freed up the trigger. I put it back together but dont have any clue on fluid or how to service it. Any help? Thanks

..Usually standard Orings are used into Pneumatics you can find them anywhere on the planet ....as far as oil is concerned you can use a low viscosity one SAE 5W (I could find SAE 2.5 W) for motorbike forks that is
not corrosive on oring and gaskets....with such low viscosity oil the piston will travel a bit faster.....

 

[azapa]

great idea on the oils guys, I had asked before with no replies. the fork oil sounds good and easy to get. how much should one put in? A Teaspoon full? Does it have to be exact? I have never seen any references. Thanks

 

[Whiskey]

It will depend on the gun that you have, here is an example from Mares for different types of their guns; on average you can see the small guns use 15-20 cc medium 25 cc and the large 30cc. I have never been that accurate in the amount of oil I put in.

USE ONLY CORROSION AND RUST PREVENTING OILS, SUCH
AS MOBIL DTE OIL LIGHT OR SAE 10 W OILS SUITABLE FOR
USE IN HYDROPNEUMATIC SYSTEMS. DO NOT USE GRAPHITE
BASE OILS! THE USE OF OILS NOT SPECIFIED FOR USE IN
HYDROPNEUMATIC SYSTEMS MAY LEAD TO PREMATURE GUN DAMAGE DUE TO INTERNAL CORROSION.
SPEARGUN OIL QUANTITY IN CC
STEN MINIMINI -15
STEN MINIMINI -20
STEN MEDI -25
STEN -30
SUPER STEN -30-
SPEARGUN OIL QUANTITY IN CC
CYRANO 550 - SPARK 550 -20
CYRANO 700 - SPARK 700 -25
CYRANO 850 - SPARK 850 -25
CYRANO 970 - SPARK 970 -30
CYRANO 1100 - SPARK 1100 Pipin -30" Mares Manual 2002

 

[MARMIR]

....teaspoon in not enought, it depends on lenght ,for a 65 30cc would be OK....