Received Air Drier for Benjamin Pump

[tcgoetz]

I received an air drier for my Benjamin pump from Sun Optics. It comes with rubber covers to keep the crystals fresh. I intend to leave the cover on when not in use. It cost $40.99 shipped.

With the rubber cover on:


Without the rubber cover, showing the brass filter:

[amb5500c]

Very cool. I didn't know they were available.
Richard

[rsterne]

How do you tell when the crystals need replacing.... they aren't the ones with the blue>pink indicator....

Bob

[longislandhunter]

I didn't know they were available either.  Pretty cool and I think a wise investment. 

Jeff

[tcgoetz]

How do you tell when the crystals need replacing.... they aren't the ones with the blue>pink indicator....

Not sure yet. I think the crystals change in appearance besides color. I may also just bake them in the oven often to make sure they're dry.

You can also buy big bags of it for cheap (900g for $23):

Here's 500g of indicating crystals for $20:

[redone1992]

interesting I didn't know they were available.

[dwood5]

I have a similar question about the silica beads [or whatever they are] that came with the 'drier' on my Hill pump. The manufacturer says they are not the typical desiccant. And they don't change color either.

They just want you to buy new beads all the time. Don't know why they couldn't be baked just like any other desiccant.

I don't use my pump, it is only for backup. I keep the openings [drier, pump output fitting] covered also to keep things dry until it is needed.

DON

[Ribbonstone]

Believe the indicator changing beats would work just as well, but need recharging/drying more often than you'd guess (esp. in my south Louisiana climate).

Old post, posted on another forum. Even though its a couple of years old, haven't seen too many independent tests.

Whatever the stuff is, it does draw moisture and won't give it up easily.  So evidently they didnt lie, whatever they are using does not act like silicon gel.

There is about 90 CCs of granular media in a dry-pac refill. OF this I separated exactly 8ccs into the following:


1. New in sealed container: 8cc = 96.3gr.
2. New in open flat container (pellet tin lid): 8 CCs =96.3 gr.
3. New into the pumps dry-pac holder: 8CCs 96.3 gr.

(Those odd plastic sealable tubes are from a Lumbar Puncture set. They come sterile pre-packaged and if they arent used, are tossed. I rescued a few from the trash, so are not only dry inside, are sterile.)

Old-used (3 mo.) DryPac media: 8ccs = 107.3 gr.

So from the start, its evident that the used dry pack picked up 11gr. per 8ccs (or about 1.375 gr. per cc) of something over its 3 months of use. Have to assume that that something is moisture. That would be about 121 grains for the whole package, or about 7.9 grams...or about 7.9 CC's of water absorbed. ALL of the old dry pack was spread out on a clean dry pan and put into a 250degree oven for 3 hours.

The 96.3gr. in the pump was subjected to 4 fills, 100 strokes at a time (50 strokes, bleed down, 10min. rest, and another 50 strokes). Temp. was 74F,humidity 78 percent thought out the test. After each 100 strokes (filling 13CI HPA tanks) the weight was taken for the 8CCs used in the pump.

100 stokes: 102.2gr. (increase of 5.9gr.)
200strokes: 104.6gr. (increase of 2.4gr. / 8.3gr. from new)
300strokes: 106.4gr. (increase of 2.2fgr. / 10.1gr. from new)
400 strokes: 106.9gr. (increase of .5gr./10.6gr. from new)

Meanwhile, the 96.3gr. sample spread and exposed to air without any pumping gained as follows:
30min: 97.7 (increase of 1.4gr._from new)
3hrs: 104.1 (increase of 7.8gr. from new)

The sealed control 8ccs remained a consistent 96.3gr. through out the test.

Back at the 250F oven, the old dry pack came in at this:
1. After 60 min: 106.7 (lost .6gr. for 8ccs)
2. After 3 hours: 100.9 (lost 6.4gr. for 8ccs).

SUMMATION:

THE WEIGHT OF WATER (at least pure lab water) IS 1CC = 1 GRAM.
1GRAM = 15.3 GRAINS (about).

(all weights below are in GRAINS)

After 3hrs. 8ccs of dry-pac grains gained 7.8gr. of weight just being exposed to the air.

After 400 strokes of a Hill pump, 8ccs of dry-pac-grains gained 10.1gr. of weight.

What ever dry-pac-grains are, they will NOT release its weight with 3hrs. of 250F baking.

(Just in case you have no handle on CCs, it takes about 30CCs to fill a 1 oz. shot glass, call it 60ccs to fill a happy hour-double shot glass. Its my New Orleans up-bringing, and the time spend many years ago as a bar tender while working my way through college the first time.)

Quick Answer:
The dry-pac-&^^& works, but it fills with moisture so quickly, it doesn't work for long. Just being in an open container in a humid environment, it is going to gain weight at a rapid pace even if you dont use the pump at all.

Am tempted to just replace the dry-pac-grins with silicon gel.  May not work any better, but will be rechargeable by baking in an oven for 3 hours and at least give a color-code to when its full.


Have no idea how old the above tins are, but Ive a few of them around  (enough to get the needed volume of silicon gel to fill the dry-pac). 
-----------------

[tcgoetz]

Here's 500g of indicating crystals for $20:

I ordered this one. I'll post again when I have it and have used it for a bit.

Anecdotal evidence for it's effectiveness: In the past when I've bled the pump after filling, I've ended up with moisture on my fingers. With the drier on today, I did not.

[Ribbonstone]

Pictures didn't transfer with the post...but the idea was there.  I like that unit better than the Hill dry-pac system (and I have two Hill pumps).

Whatever the Hill granules are, they are not traditional beads...seems to be a chemical change rather than just moisture retention, so the Hill stuff is NOT rechargeable by heating.

The traditional silica dissicants can be recharged by heating...they will fill up much faster, but you can un-fill them by heating....much more cost efficient.