CO-2 Gas bottle thread ?

[Dr. Rob]

So just for the sake of experimentation i decided to try using Co-2 instead of the usually preferred Argon mix, for MIG / MAG welding. Some folks do; thought i'd give it a try.

What a surprise when I found that the bottle has a completely different thread... the regulator doesn't fit.

What? Why would they do that? (I'm overseas, so specific brands are meaningless, but still-- they must do this on purpose. Why?)

So, I just made an adapter piece of correctly in / external threaded brass, of the usual suitable-for-machining-nuts 'n' bolts and mechanical bits brass alloy hex stock. Minimum wall thickness anywhere on the piece is 2 mm. Ideally this area won't be pressurized, but still...

Do I really want to put 200 bar into that?

Not so sure...

.

 

[Keith Krome]

You need a gasket on US(read: Compressed Gas Association or CGA) CO2 tank valve fitting, just some brass fitting isn't enough. The one I have (gasket) looks to be made of nylon or delrin.

They use different connectors to minimize the possibility of hooking up the wrong tank to a particular regulator/fitting. Flammable gases usually have left hand threads. Oxygen is different from CO2, Argon also different. Helps to keep some idiot from hooking up nitrogen to a hospital oxygen system.

They do sell adapters to convert one CGA fitting to another, within reason. I don't think you can find an off the shelf adapter for converting nonflammable gases to flammable equipment, for example.

You can also get just the nipple to change out on your regulator. Going from argon to CO2 shouldn't be a problem, and vice versa.

Edit: look at McMaster.com on catalog page 3275 has adapters and nipples.

 

[metalmagpie]

There are excellent reference pages on the Concoa site that cover the various gas threads. If you bookmark any one, you can easily get from it to any other. Try http://tinyurl.com/22et2w

Grant Erwin

 

[macona]

Most inert gases use a CGA-580 fitting. CO2 uses a CGA-320. Its so you dont mix up regulators. CO2 is only about 750 PSI full since it is liquid in the bottle. Put a regulator specifically for that on a argon bottle with 2800 PSI and bad things may happen.

You can get an adapter to connect a CGA-580 to 320. Common item.

No the problem is Europe has its own fittings as well as Japan (JIS). Since I have no clue where you are I cant help you (Hint: Fill in the "From:" field in your profile.

 

[jjock]

When I was a kid in the 50's I worked part time at a welding supply store and saw the remains of what happens when a person hooks up a low pressure regulator to a high pressure tank.
The words I'll never forget, were " it was like a bomb going off, my ears are still ringing". My boss said, " How come nobody was killed?"
I have never forgotten the message.
Bob

 

[Newman109]

Once you get your C02 bottle hooked up. I think you might like it. I tried it at the recommendation of my local professional machinist and welder friend. He uses it all of the time for his mild steel fabrication jobs.

It gives excellent penetration and, if you keep your tip clean and use some nozzle gel, the spatter is really at a minimum.

 

[peterh5322]

"Going from argon to CO2 shouldn't be a problem"

True.

And, going from oxygen to CO2 or Ar/CO2 or Ar shouldn't be a problem, either, but once you go from an oxidizer to a non-oxidizer, you cannot go back.

The regulator which I purchased with my MIG unit came with a suitable adapter from Ar or Ar/CO2 to CO2.

I needed my small CO2 tank refilled, anyway, and as it was out of date I also needed a hydro test before it could be refilled.

The place where I buy my gases exchanged my out of date "sold" CO2 tank for a filled Ar/CO2 tank, and they only charged me for the Ar/CO2 contents.

Plus, I got a nearly new "sold" tank, well within date, and the preferred Ar/CO2 valve and fitting, too.

 

[macona]

We only give back your original tank if you specifically quest it. Otherwise you get one out of the pile.

Usually people with the nice aluminum CO2 want their tanks back but usually we can exchange those as well as we keep a bunch of those on hand.

I used a proportional mixer from Smith that allows me to give any combination of Ar and CO2 with the twist of a dial.

Straight CO2 sucks... Though apparently it is still the primary mig gas in japan. There are japanese made welding power supplies specifically designed with CO2 in mind and with these is makes welding with CO2 much better.

 

[Newman109]

Macona said:

"Straight CO2 sucks... Though apparently it is still the primary mig gas in japan. There are japanese made welding power supplies specifically designed with CO2 in mind and with these is makes welding with CO2 much better.

I'm not sure what you mean by "straight C02 sucks". If you mean that it won't work for mild steel, I respectfully disagree. I use C02 with my standard Lincoln SP 175+ and it works very well. Penetration and weld bead are both excellent and as I mentioned above, spatter can be kept to a minimum with some care.

Please explain what sort of power supply will work better with C02. The Lincoln seems OK to me.

Just curious.

 

[macona]

Why deal with spatter if you dont have to? Works fine for mile steel and it is cheap. But I dont want to spend time scraping dingleberrys and cleaning the crud out of nozzles.

Very few of our customers use straight CO2. The little bit of penetration does not make up for time scraping.

Panasonic makes a power supply that does handle CO2. Expensive though.

http://www.weldreality.com/Mig%20gas%20mxes%202.htm

 

[jake67]

when i was back in welding school they would not
buy mix gas like big production shops will not
either .c02 works fine it just has a different
weld and is cheaper i use straight c02 if i run
out of mix it does weld hotter and a little less
stable for heavy work you might perfer it.