Propane to Green Gas Converter





the following information is meant for informational purposes only. i take no responsibility for anything you may do with the knowledge gained from this write up. propane can be dangerous and should be handled with care. i can not be held responsible for any damages or injures caused by this write up


this would be my newly constructed propane adapter. if you have ever played airsoft before you should know what green gas and the ridiculous price they charge you for it. for all of you who haven't played green gas is essentially repackaged propane sold at about 3 times the price (ok sure... they add a little silicon but its still way over priced!!!) i have included a picture of a can of green gas notice the type of nozzle becuase we are going to need to remove it later

now a lot of airsofters realize green gas is a waste of money and buy custom made adapters for $20 - $30 that allow standard canisters of propane to be used with their guns. i have done the same thing except instead of using CNC machined aluminum my adapter was constructed with off the shelf brass parts. this means all of you could make for very own!


Step 1: Parts

benzomatic torch head (modified)
1/4" brass coupler
1/4" brass nipple
1/2" brass compression nut (you will probably need to buy the whole compression fitting)
1/2" to 1/4" brass bushing
empty can of green gas (MAKE SURE ITS COMPLETELY EMPTY!!!)
an o-ring (sorry i dont know which size)

(sorry no picture but i will probably be making more of these so ill upload some soon)

Step 2: The Plan

i have taken a few expanded view pictures of internal workings of the adapter, it is actually a very simple device. the hardest part of the entire build process is cutting the green gas nozzle down to the right size

Step 3: Acquiring a Green Gas Nozzle

what needs to be done is essentially the decapitation of green gas can. but before you even attempt this make sure the nozzle is still good and there is no pressure remaining in the can (go outside and hold the nozzle down to be sure). after the can has been checked begin by peeling off the valve assembly with pliers there should be a lip you notice on the top of the can this is what you're trying to get off (you may need to start it with a flat head screw driver). the next step would be crushing the top a little bit so the valve assembly can be pulled out (if you are using the same green gas can as me you will notice the valve assembly is bigger than the opening in the can this is why it need to be crushed). now that the valve has been removed for the can it is safe to use power tools such as dremels. the idea is to cut the nozzle down to the size just small enough to sit inside the compression nut and make sure it has enough room to make a good seal with the o-ring! im sorry for the lack of picture in this section all i have is one shot of a finished valve...

Step 4: Building the Nozzle Holder

that was the hard part the rest is pretty much screwing fitting together. after the valve has been finalized (filled and flattened to make a good seal ) place it in the 1/2" compression nut then insert the o-ring. heres a pic of what it should look like...

Step 5: Completing the Nozzle Holder

next Teflon the 1/2" to 1/4" bushing and screw it into the compression nut. notice how the brass bushing has an extremely smooth surface on it this is to make a good seal on the o-ring to be sure no propane escapes (propane leaks = very bad). tighten the two fittings just enough to make a good seal with the o-ring but not so tight that the o-ring might be dislodged or torn. then Teflon the 1/4" nipple and screw it into the bushing.

Step 6: Making a Threaded Propane Adapter

this step should be done with great care. the first thing you will need to do is cut the torch head about a centimeter below the 45 degree bend in the shaft. next sand and roughen up the top 2 or 3 centimeters of the torch head in preparation for gluing. then mix up some epoxy (the good stuff like JB weld none of that 5 minute quick set crap) and coat the sanded area with it. next slide the 1/4" coupling over the glue making sure there is good contact between the two brass parts and be sure you leave the top half of the threads clean so that the two parts can be threaded properly. once again i am sorry for the lack of photos...

***this is the weak point of the adapter if any part were to fail it would be the epoxy. that means if it were to be dropped to hardly or improperly glued the two parts could come flying apart and possibly hit someone or something, so be careful.

Step 7: Finalization and Testing

apply Teflon tape screw the threaded adapter into the newly completed nozzle assembly and you should be good to go (assuming you allowed the epoxy 24 hours to dry) after the device is complete connect it to a propane tank and submerge the adapter in water (but not the tank). next watch for bubble, even very small ones. if you see a constant stream of them it means you have a leak and that you need to tighten or glue a part a little more. if there are no bubble the device is ready for use!

Step 8: Usage

1)screw in propane tank

2)turn valve all the way "on"

3)invert tank/valve/adapter and insert into mag or clip

4)hold in position for about 10 sec to be sure pressures have equalized

5)remove device from mag or clip and turn "off"

6)buy something awesome with all the money your saving from not buying green gas

optional step 7) add silicon to mag

because your using straight propane there is nothing in it to lubricate your gun this is not such a big deal if your using a crappy NBB from you local walmart but of your using a high end $100+ blow back you will want to lube up the moving parts every so often with silicon spray



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31 Discussions


Reply 3 years ago on Introduction

yeah they did, just like a lot of companies, but they only work on Coleman bottles, whereas this can adapt to other types of bottles since it's just threaded couplings.
the problem with Coleman bottles is that you don't find them everywhere. they don't exist here in Europe for example, so you can't buy an already made adapter, you have to make your own to go on those big 30 liter tanks directly. It pretty much comes down to doing what this guy did, but using flexible tubing as well.


5 years ago on Introduction

Nice 'Ible. I'm curently making one of these, but instead of having the bottle valve on it, it has a magazine valve, that way I can refill my empty bottles wich are easier to transport to the field :)


10 years ago on Step 8

cool quite creative. So you're sure that green gas is just propane with silicone? Wouldn't they use something more like CO2 or just air? It's kind of a waste of propane to only use it's gaseous properties but in the end not burn it. All in all a very good 'ible.

1 reply

Green gas is indeed mostly propane with a bit of silicone oil in it( some manufacturers add other gases in negligible proportions). Air is too much of a hassle to transport compressed and actually needs a regulator, and CO2 is used in some guns in a 12 gram cartridge. you need a regulator on HPA tanks so the presure going out is constant, whereas for propane, the propelant is in liquid form with enough gas vaporised to maintain high enough pressure, that way, when you take out that gaseous part, some more liquid vaporises and maintains the same pressure until all the liquid is gone :)


10 years ago on Introduction

whoawhoawhoa, why would you use explosive gas to propel an airsoft pellet when your not combusting the gas?

10 replies

Reply 10 years ago on Introduction

I'm not saying that this can't work (because it obviously does, and what you are doing is making a copy of an adapter), but "green gas" cannot be propane. More than likely it's butane or a propane|butane|iso-butane blend. Compare the thickness of a disposable propane bottle, a bottle of "green gas", and a bottle of butane lighter refill.


Reply 10 years ago on Introduction

backpacking canister fuel seems to run at about $6 per bottle vs. the $11 or so the "Green gas" goes for (in roughly 1 liter bottles). Of course, disposable propane bottles are less than $4.


Reply 10 years ago on Introduction

I've been reading the "green gas" is/is-not propane debate. While one site seems to have claimed to have done gas chromatograph (and posted data) why hasn't anyone taken a freon "side can tap""side can tap" and checked the vapor pressures with everyday refrigeration gauges at room temperature?

It's an experiment that any tinker could do at home. Heck I could do it if I could figure out where to buy the can localy


Reply 10 years ago on Introduction

If its butane then that is what i thought and that's AWESOME because then you can just use a butane refiller right? and you can buy camping butane and and an adapter


If it worked for you, wonderful! But if it did, I got news for you, it's not butane you're buying. lighter refills have propane in them as well as butane, so do some camping gas cans. the reason we use propane is because it has a higher pressure when it transforms from a liquid to a gas around 10 bars I think, whereas butane goes up to around 2.5 bars


Reply 10 years ago on Introduction

it is all about the pressure, green gas is propane with lubricant in it so it doesn't make much of a diff and... why spend more money than you have to ?


5 years ago on Step 7

Instead of epoxy, Use JB Weld!


6 years ago on Introduction

i've been using air-con Freon gas . they are cheap and had no problem with it.


6 years ago on Introduction

"Silicon" is a crystalline or glassy (amorphous) solid and is not a lubricant.  It is used for making semiconductors and is a chief component of silicon dioxide, i.e., quartz rock.

"Silicones" are polymers that include silicon together with carbon, hydrogen, oxygen, and sometimes other chemical elements.  They can be produced with short molecular chains to create an oily liquid:  That version is suitable for use as a lubricant.  As the chains get longer and are cross-linked, the material becomes thicker and denser, eventually becoming silicone "rubber".

That "e" at the end is crucial!


7 years ago on Introduction

once i get a gas gun, i will try this. has anyone found any problems?