Hand Pump
Posted: Sat Oct 12, 2013 7:10 am
I used a Hand Pump in the beginning when I started years ago and being ignorant at the time I would pump until the cylinder was full. The pump eventually failed within a year from the moisture created by the pump and yes I did drain the moisture, but after the pump failed we disassembled the pump and the little metal balls in the bottom of the pump had rusted together. I did get another pump and the recommendation I got this time was to only pump it for 20 strokes and let the pump cool down, but doing it this way seemed to take for ever to pump a cylinder up to full capacity, which to took more then 80 strokes to get it to full capacity. I also talked to a friend of mine who works for Airgas as one of there gas experts and he explained to me that you will be introducing more moisture from the hand pump into the air cylinders then a scuba compressor as it dosen't have the filtering system of a scuba compressor. The driest gas that he found that can be used in airguns is nitrogen gas, but that gas is not as readily available as scuba air.
David Levene wrote:That was particularly obvious with the old "pip-indicator" cylinders.jliston48 wrote:He said that, in his experience, most of the cylinders that have had problems had been filled from hand pumps.
They had a series of spring washers controlling the pip. Here in the UK it was obvious when the cylinder had been filled by pump, even if only a few times. The washers turned a lovely shade of rust (eventually failing).