Moisture. How big a deal is it?

[bchannell]

Nitrogen is roughtly $20 for a refill of a 40 ft3 tank. Initial cost of the lease is in the $200 range IIRC. You would get the $200 back when you turn in the tank for good. You can get larger tanks fairly easily and they're not as expensive for the volume. Nitrogen is the cheapest gas they sell. I get over a month from a 40 ft3 tank, but that's also doint a LOT of tuning and emptying and filling guns. I would venture a guess that it would last two months if used to fill normally, ie. topping off and not filling from zero too much. I do HVAC work so I need nitrogen on hand at all times, so it's a moot point for me. I tried to look and my best guess is that a full fill uses roughly 100psi on a ~300cc cylinder, that would work out to around 20 fills per tank on a 40 ft3. To mel, that's well worth the expense to not have to fool with dessicant filters and all that stuff.

I do believe if you are religious about your filters, you won't have any problems, but that cost would probably work out to close to nitrogen, AND even a filter does not keep moisture out of your compressor and line set between any output filter and the compressor. You can see mine when using air, and I had a huge filter, that kept all the moisture out of the gun, just do a search on here. I had some rust in the fitting leaving the compressor and into the first piece of fill hose. It easily cleaned up, but I didn't like taking the chance. Also, keep, KEEP, you fill line lower than your gun!!!

 

[markc_66]

more likely to have problems with moisture damage to pumps, than guns ... a key concept imo, is use a pump in a climate controlled environment to start with, less moisture 'and' heat ..i monitor humidity in my house and it can be more than 50% less than outdoors .. big factor ..

I agree, I only use my compressor inside, and there’s heat in the winter and air conditioning in the summer

 

[elwoodblues]

Water in the compressors air intake is not the biggest problem it's the oxygen, CO2, and all the rest in "air" Nitrogen removes the chance for detonation in your compressor, without oxygen there can be no combustion no water is a side advantage for guns and compressors

 

[sd619223]

i bought a filter system many people was bragging about (aluminum cylinder stuffed with filtering material). i tried blowing through it and was suprised how restrictive it is. i never used it because of that issue. if it's very restrictive,so how can that be good for your compressor + the compressor will have to work harder to fill your bottles. in nature when hot air rises and cools in colder air at high altitudes moisture precipitate out in the form of clouds. if you can remove most of the moisture before your high pressure compressor intake would seem to be the best solution. on you tube there are many videos on moisture removal using a simple radiator and cooling fan.

 

[rcs9250]

i bought a filter system many people was bragging about (aluminum cylinder stuffed with filtering material). i tried blowing through it and was suprised how restrictive it is. i never used it because of that issue. if it's very restrictive,so how can that be good for your compressor + the compressor will have to work harder to fill your bottles. in nature when hot air rises and cools in colder air at high altitudes moisture precipitate out in the form of clouds. if you can remove most of the moisture before your high pressure compressor intake would seem to be the best solution. on you tube there are many videos on moisture removal using a simple radiator and cooling fan.

You have nothing to worry about. The compressor won’t even feel it. Put together a very low pressure gauge that you can blow into and see just how weak human lungs are. Also, a good compressor set up has a PMV, pressure maintaining valve set at around 1700-1800 psi that does not allow air to start coming out of the molecular sieve drier till achieving that pressure.

 

[kaylaindy]

As a noobie, I’m reading lots of stuff regarding compressors, filters, tanks, SCBA, dive shops, desiccants, fire houses, etc. I want to be nice to my expensive new hobby, but how much moisture in our air is “too much”? With moderate usage (of our guns), moderate care (a desiccant filter on the pump), moderate humidity…. How long can one expect our guns to last before they develop the “mayonnaise” problem I’ve heard described (on a website trying to sell tanks and expensive pumps/filters). Is it really that big of an issue for a hobbyist shooter?

Thanks!

Curt

It will reduce the performace and accuracy of your gun. Messes up the reg and internal components, not to mention rust in your tank or anywhere else it can get. Youcan solve the problem for $60: PCP Oil Water Seperator Moisture Filter click here: https://www.aliexpress.us/w/wholesale-pcp-filter-tuxing.html?spm=a2g0o.productlist.search.0 and Amazon: https://www.amazon.com/s?k=pcp+oil+...pcp+oil+water+filter,aps,224&ref=nb_sb_noss_1

 

[rcs9250]

i bought a filter system many people was bragging about (aluminum cylinder stuffed with filtering material). i tried blowing through it and was suprised how restrictive it is. i never used it because of that issue. if it's very restrictive,so how can that be good for your compressor + the compressor will have to work harder to fill your bottles. in nature when hot air rises and cools in colder air at high altitudes moisture precipitate out in the form of clouds. if you can remove most of the moisture before your high pressure compressor intake would seem to be the best solution. on you tube there are many videos on moisture removal using a simple radiator and cooling fan.

Airgun components are mostly aluminum. There’s some stainless and brass and sometimes titanium. Aluminum is the material that would be of concern and that typically starts at the air tank, whether it be a bottle gun or a tube gun.
If water gets into the primarily aluminum parts of the gun and sits there it can form aluminum hydroxide, a pasty sticky goo.
It can sit there and corrode an aluminum part. If it’s the tube on a tube gun, which often times is the thinnest wall it could eventually burst through the thinnest area. Will it explode? I’ll leave that to the engineers. Either way, not a good thing. If the hydroxide passes into other areas it can cause seals to leak and a pissed off airgun owner. Note: though I have never cut apart a tube guns cylinder or a bottle guns 480cc tank I believe the aluminum liner in the 480cc is thinner than a tube guns wall thickness. Meaning less time to corrode to failure.
I spent the better part of my working life on Preventive Maintenance and run to failure mindsets and preventive was always preferred. Not to say things don’t break anyway because they do.
I look at running an airgun with moisture as the best way to learn dissasembly of an airgun. It also affords you the opportunity to send multiple emails and searching the web for replacement parts that were ruined by moisture.
However, I have read many posts of airgun owners that don’t worry about moisture and live in areas that are as dry as Arizona or wet as Florida in August. I personally don’t care what anyone does with their guns, I know how I treat my guns and that’s all I’m in control of.

 

[sd619223]

Airgun components are mostly aluminum. There’s some stainless and brass and sometimes titanium. Aluminum is the material that would be of concern and that typically starts at the air tank, whether it be a bottle gun or a tube gun.
If water gets into the primarily aluminum parts of the gun and sits there it can form aluminum hydroxide, a pasty sticky goo.
It can sit there and corrode an aluminum part. If it’s the tube on a tube gun, which often times is the thinnest wall it could eventually burst through the thinnest area. Will it explode? I’ll leave that to the engineers. Either way, not a good thing. If the hydroxide passes into other areas it can cause seals to leak and a pissed off airgun owner. Note: though I have never cut apart a tube guns cylinder or a bottle guns 480cc tank I believe the aluminum liner in the 480cc is thinner than a tube guns wall thickness. Meaning less time to corrode to failure.
I spent the better part of my working life on Preventive Maintenance and run to failure mindsets and preventive was always preferred. Not to say things don’t break anyway because they do.
I look at running an airgun with moisture as the best way to learn dissasembly of an airgun. It also affords you the opportunity to send multiple emails and searching the web for replacement parts that were ruined by moisture.
However, I have read many posts of airgun owners that don’t worry about moisture and live in areas that are as dry as Arizona or wet as Florida in August. I personally don’t care what anyone does with their guns, I know how I treat my guns and that’s all I’m in control of.

is it possible to remove 100% moisture? some moisture, i assume, is as bad as increased moisture. so is it worthwhile spending a lot to try and achieve 100% moisture removal or just maintain your rifle with a little more moisture. the only part that would be most likely impacted would be the bottle as most other parts are machined marine grade aluminum, stainlees, and other metals which can be cleaned up. wonder what the gun makers have to say about moisture issue?

 

[AlanMcD]

is it possible to remove 100% moisture? some moisture, i assume, is as bad as increased moisture. so is it worthwhile spending a lot to try and achieve 100% moisture removal or just maintain your rifle with a little more moisture. the only part that would be most likely impacted would be the bottle as most other parts are machined marine grade aluminum, stainlees, and other metals which can be cleaned up. wonder what the gun makers have to say about moisture issue?

The goal is not "to remove 100% of moisture", but to remove enough moisture so that the amount of water vapor in the compressed air stored in our tanks and reservoirs has a dew point that is lower than the temperatures at which our tanks and guns are regularly stored or used. This can be done effectively and affordably, and it is what the gun manufacturers want us to do. As a comment, this is very difficult to achieve if done by attempting to "dry" the air before any compression takes place - there is just too much water vapor in the air, even for people that "live in areas that are as dry as Arizona."

To learn more about how best to "dry" air, read this post: https://www.airgunnation.com/threads/compressor-filters-do-they-really-work.1297949/#post-1578086

And you can learn about the potential amounts of water vapor at different temperatures and pressures here: https://www.airgunnation.com/threads/use-a-filter.1287000/page-2#post-1460487

 

[rcs9250]

is it possible to remove 100% moisture? some moisture, i assume, is as bad as increased moisture. so is it worthwhile spending a lot to try and achieve 100% moisture removal or just maintain your rifle with a little more moisture. the only part that would be most likely impacted would be the bottle as most other parts are machined marine grade aluminum, stainlees, and other metals which can be cleaned up. wonder what the gun makers have to say about moisture issue?

I’ve read in several manuals of the PCP’s that I have owned that the manufacturer says “use dry air”.
Air will never be 100% dry. 100% dry would be nitrogen, and maybe some other gasses but not practical.
Ask any scuba diver if dry scuba air is dry.
One thing I neglected to say in my previous post was that most areas in airguns are anodized. Anodizing does offer pretty good corrosion protection, not as good as hard coat anodizing but pretty good. I say pump it as wet as you want, what’s the worst that can happen, airguns ain’t rocket science.
Maybe somebody should do a poll to see how many people use a molecular sieve drier vs tampon filter vs no filter. Wouldn’t hurt to know what part of the country/world you reside in too.
One thing we’ll never know unless someone ponies up the $$ to test the common methods, of all kinds or no drying, and send samples for analysis.
And then take a gun and run it with different moisture levels and see the results. Seems like it would be easier to just use a drier. Oh well, this discussion will never be solved.

 

[joedirtee]

I use the small inline filters on the compressor side AND the gun side of my whip and compulsively change the elements. Have yet to see or feel any moisture in the second filter.

 

[TRIPP]

That’s a lot of great information, everyone. Thanks mucho. I think I’m going to take reasonable precautions, including running desiccating filters, and hope for the best. I live in a fairly dry area, and I’ll be careful to keep fresh pellets and those little “cigarette butt” cotton gizmos. I plan to purchase a tank, assuming I can get it filled reasonably, and that ought to help.

Curt

I have a GX CS 4 works great, goes up to 5800 psi, which is way above the recommended fill of 4500psi for most SCUBA tanks. I shot a lot that day so I quickly got it down to 4500 psi by the end of the day...I consulted with Joe Brancato (Airgun Scientist ) or rather his assistant Andrew, and it would be hard to beat the big Alpha filter that he sells as far as reducing moisture. Mine just got shipped yesterday and I will install it properly on my GX CS 4. But, I have decided to go ahead and order the Alkin W31. I am going to compete this year , and so running out of air, when your away from home, not my idea of fun. I thought about the gas engine model, but I am going to get the 110/120 volt model, vertical position looks easier to move and I can just wheel it up on ramps or back up to a dock and wheel it in the truck, I have a decent generator used for camping so if I need to use it out in the sticks then I can and have the benefit of the generator to run anything else I might need. I would highly recommend the Alpha filter as it does seem to be the best out there for attaching to a lot of these shoebox compressors. I would feel better filling up other peoples guns and tanks with the Alkin as it leaves no doubt to the quality of dryness of the air going in. I plan on spending the extra money to get the auto stop and auto condensate drain as well. Pay I, cry once. Then make a ton of friends by having a free fill station for pcp and paintball shooters in my area who cant afford an Alkin or 30 dollar fill charge by fire supply house.. Sounds like good karma to me.....lol.

 

[TheCurtster]

I remember reading a post by an AGN member who described his “pre pump” desiccant setup, and while I liked his idea, I thought that the air would pass too quickly through the desiccant media. I’m no scientist, but I’m thinking that the longer the air is in contact with the drying media, the more water it would be able to capture. I haven’t done this yet, but this sketch should give you the idea. Take a bucket (with a lid… duh), maybe even 5 gallon size, and fill it with silica beads. Have the air pass through the filter and down to the bottom of the bucket. Then it has to pass through the beads on its way to the compressor. Silica beads are pretty cheap, and the bucket could probably be filled for less than $100
Any thoughts?

 

[AlanMcD]

Personally I would do a variant of your idea - I'd use about a 3 or 4 foot length of 2" PVC full of desiccant, and draw from one end to the other. The issue I have with the bucket is that most of the air flow would occur close to the inlet, and the outer edge of the bucket would just be wasted - you'd have a flow path concentrated in the 2-3 inched around the inlet up to the top, and sides would see almost no air flow. It would be better to have a longer flow path of about the same diameter, and you'd get much greater effectiveness out of the thinner but longer flow path . . .

 

[TheCurtster]

Personally I would do a variant of your idea - I'd use about a 3 or 4 foot length of 2" PVC full of desiccant, and draw from one end to the other. The issue I have with the bucket is that most of the air flow would occur close to the inlet, and the outer edge of the bucket would just be wasted - you'd have a flow path concentrated in the 2-3 inched around the inlet up to the top, and sides would see almost no air flow. It would be better to have a longer flow path of about the same diameter, and you'd get much greater effectiveness out of the thinner but longer flow path . . .

That’s a great idea. Think I’m gonna try it out. I’d imagine the whole thing can be made for $20-30.

 

[Squirrelmageddon]

I remember reading a post by an AGN member who described his “pre pump” desiccant setup, and while I liked his idea, I thought that the air would pass too quickly through the desiccant media. I’m no scientist, but I’m thinking that the longer the air is in contact with the drying media, the more water it would be able to capture. I haven’t done this yet, but this sketch should give you the idea. Take a bucket (with a lid… duh), maybe even 5 gallon size, and fill it with silica beads. Have the air pass through the filter and down to the bottom of the bucket. Then it has to pass through the beads on its way to the compressor. Silica beads are pretty cheap, and the bucket could probably be filled for less than $100
Any thoughts?

I made a post on this a while back. There are a few video clips in there where I used two hygrometers to measure the ambient air moisture vs the air moisture level coming out of the compressor when pre-filtering the air with desiccant and no output filter. You can pull most of the moisture out of the air before it even gets into the compressor. There was quite a few guys that said it wouldn't/shouldn't/cannot work, however, I've been filling this way now since them and have yet to change the desiccant in my tiny 4" output filter. If I didn't have that prefilter on that little 4" filter's desiccant would have turned color after 1/2 dozen fills. It's still 99% pure orange and I'm going on 60 fills.

Using a Tuxing Water Separator on the Input Instead of Output

First, this is NOT a process that is in any way an attempt to replace a water separator on the output side of the compressor. This is a project to show the effects of using desiccant to lower air moisture before the compressor. With that being said: The Tuxing is a great filter, however, it...

www.airgunnation.com

 

[TheCurtster]

Yes sir. I see no reason that your idea wouldn’t work. My thought (the bucket) was to increase the contact time as much as possible, and give the beads lots of time to grab ahold of the water. The vessel they’re in really could be lightweight, as it’s not like we’re pulling a vacuum of any consequence. I’m gonna try a 4 foot long PVC tube, maybe 2”, depending on what I’ve got laying around. As our pumps pull a very small volume of air at a time, this ought to give plenty of contact time for the silica to do its thing.
And any moisture that we can get out before it hits the compressor is a good thing, imho.
Curt

 

[silvershooter589]

more likely to have problems with moisture damage to pumps, than guns ... a key concept imo, is use a pump in a climate controlled environment to start with, less moisture 'and' heat ..i monitor humidity in my house and it can be more than 50% less than outdoors .. big factor ..

This is what I was going to say. I only fill my guns in a cool, dry environment. Definitely not outdoors on a humid day. My compressor is in a dry basement next to a dehumidifier. I've opened up tanks on my airguns and never noticed a hint of damage. Granted, these guns are all 5 years old or newer, but they've been shot plenty, and they're mint internally.

I was using a small moisture catcher but I think my Omega Trail Charger does a fine job on its own. I have used it in humid conditions on occasion, and it spits out a stream of water upon decompression. When I use it in a cool, dry environment, it spits out nothing. So that tells me there's nothing to spit. My guns will last quite a long time under these conditions. And rare, occasional exceptions such as travel or using the car battery to compress air will be just fine.

 

[extradrygin2001]

Wet air is death to a PCP, that’s why quality compressors are expensive, and if you don’t have a quality compressor make sure you have some filters on your fill line. A good water separator and a ok post separator filter will be a good investment

 

[Florida_Man]

I use a large Tuxing gold filter filled with molecular sieve. I fill a Great White tank with a Yong Heng. I recently opened two of my PCPs I’ve filled many times (cylinder guns) and not one trace of moisture.
Have in mind I’m in Florida in an old house with old 60’s windows. My humidity level is 45% at best.

I found a good way to check moisture even if it’s not visible, and that’s my guns with aftermarket huma regs. When I originally bought my PP700S I hand pumped. The pressure printed on the paper faded because of the moisture. No issues with my current setup.