Hand pump Inline filter Silica beads

[Marauder4678]

So Ive been searching and reading but i cant seem to find a straight forward answer. I have a benjamin hand pump for my marauder which has had corrison in the past from not filtering air. After researching around it seemed like my best option was a cheap inline filter and not one that goes on the intake side of the pump. I purchased one and also some silica gel dessicant to put inside it because I had read the little foam filters dont do quite enough. I havent read anything saying its ok/ worthwhile. I did read something that those beads arent supposed to be used under high pressure? just wanted to check first and get some clarification. Ive attached some photos below. I appoligize if this has been gone over to death I just couldnt find anything in my research about this specific setup.

Thanks!

 

[Joedirt199]

I put the foam filters on either side of those beads to keep the beads from being forced into the holes and jamming them. Put the cigarette style filter on the in air side and it will keep your beads clean longer.

 

[Hateful McNasty]

Well no high pressure on the intake side where your using it .., right?

(Better for you ..lol)


Look at hand pumps and compressor that got them in use and see there location . I bet 98.7941% of them are on the outlet side and high pressure .

I think I'd put a cotton type in front of the beads to catch any breakdown/ partials/ chips / dust if the beads deteriorate or crumble for whatever crazy reason ( I'm good at crazy reasons for things to go bad ) ..lol

I guess in the end it's a hope for the best in it's intended usage thing .

 

[WorriedMan]

Did same thing in early handpump days, beads "melted," plugging outlet. Suspect moisture was reason for "melting" since material re-hardened after drying. Moisture control best handled in handpumps by not overheating operation, spacing out pumping with cooldown periods. More effective downstream molecular sieve filters (pictured) need to be pressurized, adding considerably to handpump effort. WM

 

[Gerry52]

Are those the soft, blue, gel type beads? If so, you're better off using the hard dessicant beads. I'll see if I can find a link. Found it. THIS type.

Wisesorb 2 LBS 3A Molecular Sieve Desiccant Beads, Dehumidifier Moisture Absorbers https://a.co/d/1ehLbc7

 

[AlanMcD]

So Ive been searching and reading but i cant seem to find a straight forward answer. I have a benjamin hand pump for my marauder which has had corrison in the past from not filtering air. After researching around it seemed like my best option was a cheap inline filter and not one that goes on the intake side of the pump. I purchased one and also some silica gel dessicant to put inside it because I had read the little foam filters dont do quite enough. I havent read anything saying its ok/ worthwhile. I did read something that those beads arent supposed to be used under high pressure? just wanted to check first and get some clarification. Ive attached some photos below. I appoligize if this has been gone over to death I just couldnt find anything in my research about this specific setup.

Thanks!

View attachment 511731

View attachment 511732

Let's start with the technique you are using when you hand pump . . . if you are doing it "right" moisture should not be much of an issue.

How fast do you pump - as in how many seconds total from one stoke to the other- and how many strokes do you take in a fill session?

 

[rsfrid]

Let's start with the technique you are using when you hand pump . . . if you are doing it "right" moisture should not be much of an issue.

How fast do you pump - as in how many seconds total from one stoke to the other- and how many strokes do you take in a fill session?

This! If you pump slowly (like the piston doesn't get warm) then moisture should be little issue. I've been hand pumping for my HW44 for 4 years using a Hill pump with moisture beads on intake side and no rust.

 

[Neiding]

Let's start with the technique you are using when you hand pump . . . if you are doing it "right" moisture should not be much of an issue.

How fast do you pump - as in how many seconds total from one stoke to the other- and how many strokes do you take in a fill session?

While I’m not the OP, I rely strictly on a Hill MK3 hand pump for my Impact M3, Marauder, and my son’s Fortitude. I do have the Hill drying beads on the inlet side.

Regarding my pumping method, I try my best to do a “one thousand” count at the top and bottom of each stroke (but likely get impatient at times), I don’t let my the pressure in my M3 drop too low before refilling due to the volume of its reservoir, and I also try to feel the external air pump tube to ensure it’s not getting warm (or take breaks if I feel any warmth).

Am I missing anything in your mind?

Thanks!

 

[AlanMcD]

While I’m not the OP, I rely strictly on a Hill MK3 hand pump for my Impact M3, Marauder, and my son’s Fortitude. I do have the Hill drying beads on the inlet side.

Regarding my pumping method, I try my best to do a “one thousand” count at the top and bottom of each stroke (but likely get impatient at times), I don’t let my the pressure in my M3 drop too low before refilling due to the volume of its reservoir, and I also try to feel the external air pump tube to ensure it’s not getting warm (or take breaks if I feel any warmth).

Am I missing anything in your mind?

Thanks!

Neiding,

You are doing pretty well with your approach. While heat is the enemy of hand pumps, heat in the base is the problem with respect to moisture - or more specifically water vapor - in the air charge. If you do what you are doing AND keep the count of pumps per session under roughly 50 or so, then you should be good. After ~50 strokes, vent the line and let the pump cool for 10-15 minutes before doing any further pump (and venting is important as it helps dissipate heat along with liquid water). While that might seem like a pain, the easy way to handle it is to know how many shots your gun can take on ~50 strokes, and then stop shooting and refill at that point - not after as you shoot as many shots as you can possibly take. Back when I was hand pumping with my Marauders, I always tuned around a specific count of full mags (typically 20 shots, on my .22, and occasionally as low as 8 shots on high power .25 tune) even if I could get a few more - even a full mag more - of usable shots on a fill.

I'll admit I wasa withholding this a bit to see what the OPs answer was going to be, but that's the story with moisture and hand pumps - go slow and not for long between breaks to cool down the base of the pump.

If you want more on the story of water vapor in our air charge, you could read this post I wrote for those with powered pumps, but the physics are the same (I even reference hand pumps at the end of it): https://www.airgunnation.com/threads/moisture-in-pcp-airguns.1321274/page-2#post-1839770

 

[Marauder4678]

Thanks everyone for your replies!

I have not been pumping with a 1 second pause but have been stopping and taking a break at about 75 pumps. Ill slow down to 50 pumps and vent it out. I will also put the foam filter on either side of the beads to stop them from getting blown through the filter. The beads I have are hard beads not soft gel ones. This was exaclty the info I was looking for!

 

[Joedirt199]

I don't even degas while pumping. Just go slow and then take a break. Degassing means you have to waste pumps to get back up to tank pressure generating heat along the way. The first cigarette filter catches all the oil and moisture coming in to the oil/water trap.