I just tore it down and cleaned it. It was full of water and brown goo, some of which was hardened like varnish. Lots of time was spent with sand paper. I assembled it with Mobil 1. It is smooth as butter now. I want to add a desiccant pack. Has anyone done this?
but not all. Mobil 1 0-40w is fully synthetic. So I don't think it contains any hydrocarbons at all. But many "Synthetic Oils" are blended with conventional oils. So one should be careful and read labels completely...
So it might be pure synthetic, it's still a hydrocarbon oil. Synthetic oils are chemicall identical to mineral oils, it's just that they are made from other hydrocarbons rather than being dug up out of the ground as part of crude oil and separated out.
Interesting Hill told me NOT to use any type of oil
August 24 2010, 11:11 AM
I imagine pumping is slow and and might not reach the ignition point ever. I would be concerned what the engine additives does to the Orings depending what they are made of. If it was an O2 tank I would run when he started to pump.
Given the small mass of the air, slow compression and all the metal around I don't think fire is the issue. I think that the problem is any water that happens (and it will....) will not mix with the oil but rather gum up the works with 'mayonnaise'. I bet this is the sludge guys find that kill their pumps. It's just too thick to be 'blown out' when the vent is opened?
To get a flash fire you'd need a faster pressure change on a larger volume (like happens in a diesel engine or when a HP chamber is rapidly charged from a HP source. For instance, oil and grease on gun tank walls seems to not be a problem (and is suggested to protect from rust), I suspect becasue the fill rate is low.
The point I was trying to make is 'synthetic oil is safer than hydrocarbon' is an oft repeated but incorrect idea. The former is more pure than the latter, but basically the same chemicals. Either will burn.
You will need some brass-pipe an 90 degree elbow. Depending on what series benji pump you have. Mine is a series 2, Sun Optics is the supplier of the Benji pumps and the repair center as well. Duane Sorsen a great guy @ Sun-Optic is the man whom does the rebuilds etc on these pumps.Sun is located in or at Burleson, Tx Phone #817-350-4958. You can use the oem screen that is screwed on the pump have now. Remove the srceen on pump base and place pipe or adaptor to pump-base can't remember size take sreen with ya to hardware store and start by sizing it to pump base for starters. Anyway use short pipe or elbow from pump base out to another pice of pipe than add mini dri-filter to threaded part of pipe. On top of dri filter thread an adaptor to be able to screw in oem screen from your Benji pump base.
As far as using oil on pump shaft that is what Duane Sorsen told me to use on mine . never had a problem yet and it has been a year of pumping and scuba fill use on my PcP rifles. I don't mean give the pump a bath in oil just lightly use with some common sense. Adding a filter is easier done that explained. When dessicant turns say from blue colot to pink or white depending on descant I remove it from filter and place in a alumin baking pan. Bake at 240 degrees in oven for 2-3 hrs Dessicant will turn blue in color again. Place back in filter carefully so you don't loose Dessicant balls. Put filter back togeather and you are ready to use again and again til Dessicant won't turn color anymore after baking as stated above. If Dessicant won't turn orginal color of blue etc than it can be bought say at Harbot Freight etc It dosen't cost an arm or leg either.Hope this helps.
I got the filter at Lowe's store any Home Depoe or
September 5 2010, 5:00 PM
Harbor Frieght you can order from them as well. It is a mini inline dri-filter. Or you can pick one up at a place that sales air compressor supplies or parts. It should have the Blue Silica Desicant in the filter. Which when it turns pink color I take it the desicant out of the filter and regenirate it it the oven at 240-degrees foe 2-3 hrs it turns blue again the desicant that is put back in plastic housing part of filter. Put filter back togeather and screw filter back on plumbing part that is in or on pump.
Hope this helps......
I used fully synthetic Mobile 1. I have tried to burn it...doesn't happen. I even tried to burn it with a torch...it just boiled. I coated the internals in oil and replaced a couple of o-rings. The rod and intermediate tube had a ton of herd gunk on them so I turned them smooth with some 600 grit sandpaper. It works smooth as butter and pumps quicker because of the new o-rings. The silicone grease seems to bind a little and does not perform as well as the oil. You can't wipe this oil off. There is ALWAYS a film on the metal. It is so slippery you can't hang on to it. I talked to sun optics and they said the oil was fine.
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