What's true about CO2?

[Zone Drifter]

So I don't really use Co2 anymore, but I got a 20oz tank, stripped it and I'm getting it hydro'd. Then, either cerakoted or powdercoated. OR, shiny and clear aluminum anodized. Either way, I just want a pretty C02 tank for no reason other than smiles and shrugs.

I wanted to get some info about this stuff, like we all used to swear by three things with C02;

-Get an expansion chamber to help the liquid turn to gas. Did these really do much?
-Get an anti-siphon tube installed to prevent liquid. (not possible to install on my updated valve, but the valve prevents a blowoff.) Did these work also?
-Run only a remote line to give the liquid/gas ample distance and leave the tank vertical. Seems to work well enough.
-What was the normal pressure these tanks ran at given a 75 degree day? I assume somewhere around the magic 850 psi.

What experiences did all of you have? I know my old spyders ran expansion chambers, but eventually snow would shoot out of them with enough use. Same with my old A5, even with an expansion chamber. Now compressed air is far superior and I do have a shoebox compressor so not like I need to use C02, but it's just my way to make old things pretty for no reason. I'm really leaning towards polishing and clear anodizing the tank. But lets be real, I have a local powdercoat/cerakote place and they do great work for a good price. I would just lean away from cerakote because it's not as easy to strip without abrasive blasting.

[Euphie]

I played on co2 alot, and in many different formats, all of this is as best I can recall as most of this is from 20+ years ago.

I ran huge co2 tanks on my Shocker, mostly with a remote. I have had an Impulse with an antisiphon on an angled drop. I played vertical co2 on my Autococker, and also remote with expansion chamber and dual regulators, I ran a remote with expansion chambers on the remote and on the foregrip for my Automag, I used liquid co2 with a siphon tank on my Tippman .68 special.

Those all worked out fine, good consistency and not much trouble but, I do have a few notes:

The Shocker was absolutely great, sometimes I ran an expansion chamber off of my remote (which was just another tank filled with BBs) and other times just an old 68ci or 114ci tank that had a co2 valve installed and filled with co2, as I couldn't fit two tanks in my pouch. The Shocker really didn't need the additional expansion chamber, the Max-flo did great even chewing through case after case of paint. My Eclipse Shocker got covered in frost at a tournament, and it still shot fine so, it seems way more tolerant of the cold than most electros.

The Impulse used a Maxflo as well and was good, but perhaps due to the higher fire rate at a certain point would experience some shootdown and it would have to warm up a bit in order to fire right, but it never stopped functioning or had really hot shots from expanding liquid co2 and all I had on it was the angled ASA and antisiphon (which was setup specifically for that ASA). I didn't have an expansion chamber so maybe it could have been better than it was, but overall it was worse than the Shocker, but still the fact you could rip 16 shots a second off of the break on co2 was pretty impressive.

I ran a vertical 9oz co2 on both my 98 Autococker and my classic mag, and most of the time it was fine, under heavy fire the automag would experience velocity swings that were pretty massive and I once had the LPR hose pop off of my Autococker, but switching to a Palmer Rock totally solved that problem for me. Still if I went crawling sometimes the Autococker would experience wild velocity swings as well indicting liquid co2 was probably in the valve, I would assume from the fact that you cant really keep the marker vertical while crawling. So for me this was playable, but not nearly as good as the other methods I did.

Eventually I got my remote setup with the expansion tank, hooked to a 42" steel braided hose, a PMI Perfect gas thru stock and a maxflo and a Palmer stabalizer for my Autococker. At that point it was rock solid on co2, aside from getting a bit cold it was basically like shooting the Shocker at that point. I did change the valve and do a bunch of other things to that Autococker but, I don't think those things had near the effect that double regulation and a remote had on it.

The Tippmann .68 special was by far the easiest, the siphon is just a straight tube. It ran amazingly consistently too despite having no regulator, with the only real downside being the huge plumes of co2 that it would give off while shooting as it would actually obscure your vision. This was the gun that convinced me that if you can just run liquid do that instead. It was simple and bulletproof and it didn't seem to matter how hot or cold it was, it just worked like normal.

Output pressures are a bit harder, as best I can recall it was generally between 600 and 1200 psi I didn't have a gauge on the tank output for many of my setups though. I had enough pressure range to double regulate on an autococker and keep a 200psi difference between regulators though.

The one maker I could never make work right on co2 was my Bushmaster BKO, no matter what I did it would experience shootdown, and it would freeze up very easily.

[glaman5266]

-Get an expansion chamber to help the liquid turn to gas. Did these really do much?
-Get an anti-siphon tube installed to prevent liquid. (not possible to install on my updated valve, but the valve prevents a blowoff.) Did these work also?
-Run only a remote line to give the liquid/gas ample distance and leave the tank vertical. Seems to work well enough.
-What was the normal pressure these tanks ran at given a 75 degree day? I assume somewhere around the magic 850 psi.

In order:
-Yes & no. I think it kinda depends on the platform. For instance, I feel like they benefit STBBs more than Tippmanns. The Tippmann CVX valve is one of the best valves ever made for co2 & doesn't really need one.
-It does help, but then you're tying that tank to that marker/ASA. The anti-siphon tube has to be oriented just so, and that only works with the ASA you're going to use that tank on. And as I said above, the benefits may depend on the platform. It's also not practical if you want minimal pieces of equipment and/or don't have disposable income.
-This is a good way to keep liquid from entering the paintgun without an anti-siphon bottle, but it has it's own drawbacks.
-800-850 psi under ideal conditions is what I've always read.

As for experiences, people's mileage can vary. Some people will say they help & some will say they do absolutely nothing at all. My experience says they do work- to a point. When I started playing regularly, I used a JT Excellerator 6.0 (JT Spyder clone). Those came with the cheapo PMI regulator from the factory & I had nothing but issues with it on co2. Compressed air was not commonplace or affordable at my location at that time (2003), so I had to change it up. I put a 4-stage expansion chamber on it & put a weaker hammer spring in it. Not only did it actually work reliably, I saw more consistency & my efficiency went up to 1000+ shots off a 20oz bottle.

Now would I put an expansion chamber on a Tippmann? No, because the CVX valve is designed to force co2 to expand as it enters/while inside the valve chamber. I feel like there would be minimal (if any) benefit to having an expansion chamber on a Tippmann. My Pro Carbine works wonderfully on either gas, so there's no point to adding the weight IMO.

I can see expansion chambers, along with an anti-siphon tube, working well with co2-sensitive markers, like Classic Automags or Minimags. But at that point would it be worth it when you can just run a HPA bottle? It's certainly not practical compared to HPA.

What co2 is best for these days is for Nelson-style pump guns & older paintguns that were designed to run on co2. I'd argue that co2 is the superior gas for those paintguns, and by a fair margin. And considering how much work it takes to make some older paintguns run on HPA, co2 will always have a place with them.

[Number six]

Ok, so as best to my limited knowledge, co2 is stored as liquid by weight, not pressure. It's more sensitive to temperature than hpa, hence expansion chambers. The general gas law is pressure1 x volume1 / temp1= p2 x v2 /t2, which will tell you the pressure of a tank at a given temp. Increasing the volume (via remote or expansion chamber) lowers pressure at the same temp. Likewise, lowering the temp decreases the pressure at a given volume. Getting liquid co2 into your marker means that it's going to all blow out of the valve when you fire it. The huge drop in pressure (and temp) when the marker's valve is opened creates the frosty flakes coming out of the barrel (volume spike). Expansion chambers were a way to keep just the gas going into the marker. On a hot day, though, you get velocity spikes because of the pressure increase at a given volume.
Furthermore, if I'd known this stuff when I started playing at Camp Pendleton in the late 90's (when they only had co2), I would have been running a remote in addition to the expansion chamber on my Spyder! My team took so many penalties because of hot shots, we weren't even in the running. We played well, though.

[Trbo323]

Don't use an anti siphon tube AND a remote line. Putting the tank vertical will turn that anti siphon tube into a siphon tube until the tank gets low enough, so at some point you will go from drawing liquid to drawing gas out of the tank.

One or three other, not both

Sent from my motorola edge 5G UW (2021) using Tapatalk

[Chappy]

Increased volume does not equal reduced pressure. As long as there is liquid in the system the pressure will remain the same except for the shoot down from temp drop. Otherwise you are pretty well right on.
Then there’s running liquid which is its own beast. I’ll be running a siphon tomorrow in fact. Been a while.
Oh yeah and co2 smells better!!

[Number six]

Right. Increasing volume only reduces pressure if it's already in gas form.

[Arthur]

I’ve run cO2 on 98s and A5, a really long time ago. Got the job done but wasn’t perfect. I made the switch to hpa and space guns pretty quick.

I do use cO2 on occasion with my FSC. A lot in the back yard too. It shoots FS really well.

[SignOfZeta]

I only play pump so I just plug the bottle in and go. No anti siphon, no remote, no expansion chamber. 20oz is a huge tank though…

Last year I used HPA for the first time. It runs way bigger more expensive tanks that only last a fraction as long as CO2 and I can’t fill at home. I’m sorta not impressed but I will continue to use HPA only on my Sterling.

[Brokeass_baller]

Why HPA only on the Sterling?

[DocsMachine]

I'm surprised no one has said this: DO NOT POWDERCOAT OR CERAKOTE A TANK!!

Unless the coating is 'cured' at less than 200F, absolutely do not use it on a tank.

A CO2 tank gets a great deal of it's strength from the heat-treating of the aluminum. A trip through a 400-500F curing oven can and will anneal the tank, removing a good deal of that strength, making it a very possible potential bomb.

Anodizing, spray-painting, hydro-dipping, 2-part epoxy paints... any coating that doesn't take a great deal of heat to dry/cure is fine.

Doc.

[Euphie]

Cerakote offers quite a few air cure colors, I know some people cure the oven cure stuff at 150F for 2-3 hours rather than 300F for one hour for the H series coatings, but the V-series needs 500F. So you can certainly do it, but you have to communicate with whoever is doing it. You don't really need V-series coatings anyway on a paintball gun as that coating is designed to handle 1800F which hopefully won't be happening on the paintball field.

[Pyrate Jim]

Co2 is a phase change material much like water. It can be solid, liquid or gas. These changes Are determined by pressure and temperature.
You can store a lot of gas in liquid form. Unfortunately, Co2 is sensitive to small fluctuations in pressure that affect temperature. Not a problem with a pump, but the high RoF of electros will drain the tank fast enough that the pressure loss drops the temp below the liquid phase. That liquid is cold enough to freeze O-rings or other components that can affect a markers operation.
Things like wild velocity issues, spiking high when liquid in the valve is released and the liquid suddenly expands into gas and effectively "supercharges" that ball. Drop the pressure fast enough and it will almost reach the solid phase and start shooting out dry ice "snow". Real trouble for some regs.
Compressed air does not have that problem and became the air source of choice in tournament play & speedball fields. As a bonus, it silenced the environmental extremists who claimed that the game was releasing greenhouse gasses into the air (even though it was collected from the atmosphere to begin with)

Don't get me wrong, Co2 is a great choice for storing gas, as long as it's a gas form when it reaches the valve. A 20 oz. bottle of Co2 gets about four times as many shots as a high pressure air tank of equivalent volume. It's getting it to gas phase and keeping it there that's the problem, hence the expansion chambers and remotes.
(Although I personally like remotes to keep weight off my hands)

Since I've only played stock class the past number of years, it no longer means much to me but I've had my day in the tourney scene as well.
I might add, I can purchase 1,000 12g's for the cost of one HP bottle. That was a seven year supply the last time.

[jetenginekyle]

I'm surprised no one has said this: DO NOT POWDERCOAT OR CERAKOTE A TANK!!

Unless the coating is 'cured' at less than 200F, absolutely do not use it on a tank.

A CO2 tank gets a great deal of it's strength from the heat-treating of the aluminum. A trip through a 400-500F curing oven can and will anneal the tank, removing a good deal of that strength, making it a very possible potential bomb.

Anodizing, spray-painting, hydro-dipping, 2-part epoxy paints... any coating that doesn't take a great deal of heat to dry/cure is fine.

Doc.

To my limited knowledge most anos are sealed in boiling water that has additives, would this sealing method cause issues? Is cold sealing be the only work around?

[Euphie]

There is a cold sealing process, it needs some special nickel/fluoride chemicals, I have been looking into doing some home anodizing and everything told me hot sealing is much easier to accomplish, so it is possible that heat treated aluminum is cold sealed to preserve it, though I don't have any firsthand knowledge from someone who makes tanks

[Cyberpyr8]

I had an anti-siphon tank on my first Ion back when I started playing. It worked fine and the Ion could ramp and not have any issues. I soon switched to a air tank and never used it again. But It worked whereas before I put the kit on the tank, it would freeze up. I wouldn't recommend one today since there are so many better alternatives, but it did work. As someone else mentioned, you had to match the siphon to the ASA and the tank would pretty much run great on the gun it was intended for and not many others.

I would say hydrodip the tank. It's one of your best options for not ruining the tank. Everything that I have had done has held up well.

[Chuck E Ducky]

I like 12g other than that I’m running HPA .

[Myrkul]

I've been trying to get into some liquid Co2 builds, (68 special, Mega-Z) If I'm slow on the trigger or just taking pot shots, the velocity is hella low (like 230 fps). Once I start ripping it climbs up to 290 fps. If I slow down or wait for over a few seconds it drops back down. I'm not sure if Its an issue with how I'm building my siphon tanks or just the local field being wildly incompetent at filling Co2(They are, I once got 50 shots off a 9 oz that they told me was full...the gun didn't leak either. They just can't seem to figure out how to fill them correctly). I haven't quite given up on them yet, but for guns I actually use, I go 12 gram or HPA every time.

[Brokeass_baller]

Myrkul they probably aren't chilling the tanks first. They need to fill a bit, and dump it a few times to cool the bottle. Then it'll take the liquid better.

[DocsMachine]

To my limited knowledge most anos are sealed in boiling water that has additives, would this sealing method cause issues? Is cold sealing be the only work around?

-No. Boiling water is only 212F, and that's fine. But Cerakotes and powdercoats are generally cured at 400-ish F, which is definitely dangerous. (People have been killed filling powdercoated SCUBA tanks, for example.)

All too many people have argued that the coating they want to use 'only' needs 300F or so- and in my opinion, that's just too close.

So my personal rule of thumb is if the stuff needs to cure much above 200F, don't risk it. There's plenty of paints, 2-part epoxies, hydro-dips and other coatings- or full-on anodizing- that are safer.

Doc.

[jetenginekyle]

-No. Boiling water is only 212F, and that's fine. But Cerakotes and powdercoats are generally cured at 400-ish F, which is definitely dangerous. (People have been killed filling powdercoated SCUBA tanks, for example.)

All too many people have argued that the coating they want to use 'only' needs 300F or so- and in my opinion, that's just too close.

So my personal rule of thumb is if the stuff needs to cure much above 200F, don't risk it. There's plenty of paints, 2-part epoxies, hydro-dips and other coatings- or full-on anodizing- that are safer.

Doc.

thank you for the explanation!