Rust on hand pump

[Drummer87]

I got the Air Venturi mk4 hand pump about 3 weeks ago and today when I went to fill my gun I noticed rust on the air cylinder. I’ve lubed the pump with the silicone lube like the directions said to, the pump is kept in the house with my gun in a case when not being used. Do I need to lube it more often or what can I do to help prevent the rusting.

 

[JW652]

Taking a pump from an airconditioned, inside environment to a warmer and more humid outside environment will cause condensation. It helps to wipe it down after it reaches outside ambient temp. Same with metal rifle barrels, etc. There are a lot of good products that will help ameliorate the effects - at least on exterior parts. Divers' specific silicone - which is designed to resist a salt water environment - may be the best for the pump tube.

 

[marflow]

I'm guessing but I think you will have pump problems before long

rust or corrosion and O-ring and or seal are not friends

 

[Drummer87]

Yeah I’ll have to check out the local dive shop to see if they have any of that silicone. Can I use a gun cleaner to help get rid of the rust and then just work on prevention after that

 

[airgunfans]

The place you store or use the pump must be very humid. I have never lube my Hill Mk 3 pump and there has not been a single dot of rust after 3 years of use. 

 

[C.B.Daddy]

Oh my!!! I’m so sorry that has happened to you. That’s not normal to me! What type of finish was on it to begin with? Was it mirror polished? Looks like it was put away wet possibly by accident not realizing condensation had or was going to form. That’s my two cents. My son left his Benjamin hand pump outside for a few days and nights and it did the same thing. I put it in the lathe and re polished it. I was barely able to salvage it. If you don’t have a lathe, set up with a drill motor to spin it. Get fine emery cloth and polish away! Very fine! From one end to the other evenly. Make sure you do not dwell in one spot for too long if you decide to try it. Of course it will need to be disassembled and it might be a two person job. A trigger man or woman and the polisher! I hope it works out. If you can’t get it take it to a machine shop if possible. Or you can send it to me and I’ll polish it for you free. All you would have to do is pay for your shipping. I’m around Fort Worth Tx. Good evening 

 

[Drummer87]

I live in Ohio so I think what JW652 said is most likely the reason behind the rust with all the humidity we have. It is stored inside then the condensation that builds up as I take it outside and then the moisture that it is exposed to from the humidity. I slid the tube as far back as I could used my gun cleaning brush and started scrubbing got most of it cleaned off and lubed it up really well. If it get worse then what it was I can take it to my work and stick it is a lathe there, I’ll just need to figure out how to take my pump apart.