Does anyone still use Liquid Co2?

[Myrkul]

My desire for variety might be outweighing my common sense a bit here, but does anyone still run liquid Co2 regularly? My field does still fill Co2, (occasionally correctly even!) and I have enough loaners at this point that I'm not worried about being short for friends who want/need to borrow something.

Recently I have been really enjoying my older Tippmann gear, so much so that I just picked up an old Pro-Lite. Currently it is shooting in the 235 range on HPA, and 290 on unregulated Co2. In the back yard testing I did pretty much the second I jump on the trigger the velocity jumps to around 320 (shooting down hill, so liquid was unquestionably getting in the valve).

I'm obviously not going to be running this as my main shooter, and my brief research seems to indicate that "back in the day" a lot of people would set these up as dedicated liquid platforms for the winter. Is it the worst idea ever to just pick up a 9oz, siphon it, (I've build several siphon tanks before, just never used them) and call it good? My understanding is that I would be giving up a good deal of efficiency, but in return it would be much more consistent, less sensitive to temperature fluctuations, and allow me to dial back on the main spring pressure quite a bit with an RVA. Additionally I'd be able to run a nice small 9oz tank, instead of a 13Ci HPA tank with an SHP and then refilling it every half a hopper. And it would be cool as hell to see those liquid Co2 clouds going.

Am I missing anything or is this a pretty solid understanding of what switching to a dedicated liquid set up would do? Does running straight liquid even out the velocity fluctuations of Co2 significantly, or should I expect it to be about the same as regular Co2? Any other thoughts, tips or old school tricks?

I'm curious to hear your thoughts!

[infamoussmiley]

I live on liquid CO2... I even prefer it over anything else. It's just harder on the seals. And in the summer, it can cause spiking. Depends on the marker for what is best. Older Tippmanns love the liquid CO2. If running RT, great until you frost up

Best,

Smiley

[Myrkul]

So the pro-lite had original seals still in it this weekend, so its going to need a rebuild. I'm assuming since liquid is harsher I'll want to use exclusively urethane "o" rings to rebuild it? or can I "get away" with using buna from the hardware store like I do on everything else?

[glaman5266]

My understanding is that I would be giving up a good deal of efficiency, but in return it would be much more consistent, less sensitive to temperature fluctuations

I've never run liquid co2, but it seems like these are the main reasons for using it. I think the consistency comes from using X amount of liquid, so you'd get consistent expansion inside the marker instead of trying to get it to expand before it gets into the marker. This also lets you run it in the winter.

Paging Hp_lovecraft

[coyote]

The velocity problem with hpa likely stems from using a tank regulator with too low of an output pressure.

[Myrkul]

Nope. Tank is 850 PSI output and runs all my classic mags and my 68 carbine. It's a volume/spring issue, and it seems like Pro-lite springs are a bitch and a half to find so want to side step replacing them.

[coyote]

If it will run a mag it will run a Tippmann.

[Meleager7]

Subbing this interesting thread to follow, as I think liquid co2 is such a fun idea to mess around with!

I've been meaning to scratch the liquid co2 itch for a couple seasons now, ever since i picked up my 68 Special in 2018 . Followed by a Montneel Z-1 last summer. I even had a new Siphon tank fabbed up by a member here for this purpose.

My challenge has been the co2 fills part. None of the fields i play at fill co2 anymore. I have a local surplus store that will do fills, but they are overpriced and incomplete fills ( he has no scale, weighs it by feel!?? ) so i try to avoid him.

My only real option left is investing in co2 tank rental, and buy a fill station, but I've been holding off due to the expense for such a niche way to run your gun nowadays.

anyhow, enough of my problems, back to your question.....

I\m interested to find out how what results you get, because from what i have read about the subject, once you fire a few charging shots to draw liquid up into your valve, you should start seeing really stable, consistent velocities. On a related note, this charging valve with liquid, is how you should be chrono'ing your gun by the way.

I think the consistency happens because the volume inside your valve is static. The liquid co2 in the valve cannot increase or decrease in pressure because it's in a liquid state. The combination of valve spring tension, hammer weight, and main spring tension mean each shot should be a metered amount of liquid co2 that escapes and instantly expands into co2 , propelling the ball.

Also, not sure how big your collection is , but i've always hoped someone would do a series on here called " Will It Go Liquid?? " , so just thought i'd plant that seed here

[Brokeass_baller]

You don't have an AirGas near you? They'll fill consumer tanks. I've also found food supply places will too, as they usually fill CO2 tanks for soda fountains. Dick's Sporting also still offers CO2 in some locations. Just a few ideas.

[Meleager7]

thanks, I'll check these ideas out. I'm in Canada and I think Air Liquide is what we have.

[Chappy]

Yes it is a volume system not a pressure system. It can be incredibly consistent with decent paint.

Keep below 88*f , if you get over that your co2 will go critical and turn to gas which means low FPS. High humidity days are rough too. The clouds become really bad and linger. Also, moisture will collect in the barrel causing lots of zingers.

As previously mentioned, chrono after the valve is flooded, meaning you’ll need to shoot sometimes quite a bit to make sure depending on volume. If the gun has minimal volume like a Z or a prolite it’ll take 5-15 shots. Something with more hose and valve volume will need more. Which brings me to next point...

Minimize the volume in your system. Zs are one of the most efficient liquid semis and take the least to flood because they have small volume and tight air passages. I use a bottom line on my Z1 and I filled the braided with 1/8 inch tubing and it cut back a few shots for chrono.
And the less room for expansion, the more consistent and efficient it will be.It’s the complete opposite of running air. Most guns that have trouble getting velocity on hpa are good candidates for liquid.

Keep your tank slightly warmer then your fun and your usually alright. This naturally occurs since the expansion at the valve will cool that part of the gun first. But after long sits if the gun and tank are too warm it can take a bit too glshoot enough to cool everything off.

The good side of alll this is if you properly chrono, you do so at the fins peak velocity. Your only going to drop fos with temp issues so it’s very safe when done right.

Settingup your tanks right is critical.
First consideration is finding the proper valve. If the co2 valve has a safety channel in the threads with the hole drilled through, it will not function. The valve will draw the gas through the channel as it bypasses the dip tube.
Also some valves don’t have the bottom plug threaded 1/8”npt so it’s not a straightforward swap. The best valves to find are off older tanks like the 90s Catalinas.
then you have to make sure they are set up correctly to suck liquid when they are on the gun. Pretty straightforward but you have to think it through. I hat soft tubes that ding so I set up 2 16oz tanks that worked on all my setups with hard tube.

[Myrkul]

Right on, Thank you for the tips and extra info! Pro-Lite is still in it's stock configuration so I don't think there is much need to reduce any volume on it.

On my previous siphon tank builds I used copper hardline and matched it to the guns ASA. I also did encounter those stupid safety channels with the holes before, I just drill the holes out and tap them for 10-32, then Loctite set screws in the holes. It works well. I'll post up pictures when I build this one.

[OpusX]

The best valves to find are off older tanks like the 90s Catalinas.

Oh so convenient that I have this sitting in the rehydro pile. Myrkul I'll be needing one syphon setup for the ProAm please.

[Myrkul]

Just the one? I have like 20 ft. of copper hardline tubing that needs to get used up....

[OpusX]

The rehydro pile right now: 12oz (Java for a spyder build), 9oz stubby (perfect size), 20oz Catalina (for the syphon) and then perhaps another 20oz just cause. Don't think I'll need another syphon bottle....

[Myrkul]

Do you want me to anti-siphon the others?

[Hp_lovecraft]

Ever since I bought a 68-Special in 1990, I have only run siphon tanks. I don't play as often these days, so I'm always struggling to make sure all my tanks are in hydro. Last time I played, I only had a 7oz siphon. Literally the one that came with my 68-special 30 years ago!

Chappy covered it, but it is really a "lost technology". You have better performance then when using HPA. No hot shots, no creep, no shootdown, no spikes, No regulation to fail. Lighter then HPA systems. Cheaper. Better accuracy (consistent FPS). I dont think I"ve touched my velocity adjusters in 20 years. All my guns will shoot around 280, all day, except when super hot out.

I know this seems incredulous. Why was it abandoned? In short, while some guns run fantastic on liquid, some guns will be destroyed. Anything that needs a regulator is a no go. Technically, the Vector and Palmer Typhoon were designed to be capable of running liquid, but its not ideal. Certiantly not mags or cockers. and once guns with solenoids came out, and other pressure critical components, there was pressure to stop using siphon tanks.

Tippmann infamously dropped support for siphons when it released the 98-Custom. It allowed them to use cheaper parts, not to mention lessen the liability associated with idiots putting tippman siphons on electropneumatic guns.

Its weird today, because so many fields are abandoning co2. One popular reason is that co2 is dangerous because of all the FPS spikes. But.... this wasnt an issue in the 90s, when most rentals were pro-lites using siphon tanks. When fields upgraded to 98-Customs with standard tanks, and they would spike as the temperature rose...

But in short, if you are using a blowback, then in general, you should have great success with a siphon. Better then if you used HPA..... as long as the field fill co2. haha

[XEMON]

My local fields are dropping CO2 because noone wats it and they dont want the expense/work of running a second air system ...
Only 1 field fill them locally ...
I had field that didt let me play with 12g because they didt knew what it was ... (thought it was a homemade system...)

[Myrkul]

I have also made an ill advised Ebay purchase of a 68 special recently, so I'll probably be rebuilding and getting that up and running along side the Pro-lite. Funnily enough I also have a 7oz from 1992 that I used to use pretty regularly until I moved about 3 years ago. I'm very very curious to see how these turn out!

[Chappy]

Chappy covered it, but it is really a "lost technology".

[Criticalhammer]

I blame AGD with their compressed air and wiz bang space guns.

[Myrkul]

I started digging through the pile of expired Co2 tanks in my basement and quickly found a good valve and slapped this together....almost too easily. I might disassemble it and fill the hardline with smaller tubing as Chappy recommended if I'm not happy with the efficiency I'm getting, but this should get me up and running for now.
1/4" OD copper tubing with a 1/4"C X 1/8 NPT fitting incase anyone wants to know.

[tarakian]

While copper will work, it's not the best option. We always made ours from plastic tubing with a fitting on each end. That way it will always hang on the "bottom" of the tank, no matter the orientation. I'm sure I still have some in the tool box, I'll get a picture after work and post it.

[Chappy]

I can almost smell the CO2 on the air...

[Tarsun2]

lol maybe its this dang mask, or maybe its a heavy case of nostalgia; but I was thinking the same thing as I'm reading through this thread.

[Myrkul]

Got the 68 Special in! Tippmannparts.com told me they'd go through it and replace as many seals as they could since they had plenty of urathane "O" rings, but didn't know the sizes for the 68 Special. They said they'd make a kit available on their website once they get it all figured out though! So obviously I just dropped it of with them, they said I'd be able to pick it up some time next week 😁

[Meleager7]

I’d buy a rebuild or two!

[Jordan]

http://68-special.blogspot.com/2013/04/til-genorid.html?m=1

Some oring specs there.

[Myrkul]

Thank you! That is super helpful, I'll be sure to pass it along to tippmann parts!

Thank you!

[Jordan]

The vlogger used to be on this forum but I think he got chased away.... he was pretty obsessed with 68 Specials and had a couple of neat projects in the works.

[StrayBlackCat]

Still kicking, dropped off the paintball front because of heart issues. Was not aware the vlog was still being visited. The needed duro ratings are not listed on that service document. I was in the process of reorganizing the vlog so much of the data was pulled down. I do have the duro ratings and the source stock numbers, if the o-ring supplier is still in business.

[Myrkul]

Update:

Finally got around to rebuilding the Pro-Lite. I did a full rebuild (with all urethane seals), drilled the back cap for an RVA (more on this in a minute) and went ahead and de-volumized the gas line with some vinyl fuel line. Its in there SUPER tight.





I unfortunately had to chrono pointing down since the siphon tank my field "filled" for me was empty within 20 shots. Once I got it shooting in a safe range though it was extremely consistent, AND more importantly, I was able to take so much pressure off the main spring that the trigger pull improved dramatically. Its MUCH lighter now. If you look closely at the back cap you can see the back of the main spring through the hole to gauge just how much less spring tension you can remove by switching to liquid.