No gas for my welder,so a question

Can I put my steel to be welded into a box with blocks of dry ice,to displace the air,to get a better weld?

Just how cold do you want your steel as you’re welding it?

Just like humans, cold isn’t good for penetration.

NO!

Not applying dry ice to steel, but dry ice to water, really don't think the steel will.get that cold. Only in co2 box for a few mins.

What the heck, give it a shot.  CO2 is a suitable shielding gas. I imagine there will still be enough oxygen in the box that you will not get a good result.

Pick up a roll of flux-core wire?

I have flux core wire.  I am just thinking of a co2 fog in the box.

We will know the answer as soon as you report back.

My thoughts are that without a flow of gas to keep things fresh, the CO2 atmosphere around the weld will become contaminated/saturated with whatever volatiles come out of the weld and not do a good job of shielding. That said, as a McGiver episode where the Hero had to complete a small welding job to save the good guys, I would say that the dry ice has potential. You just need to contain and compress it a bit maybe in a bouncy balloon so you can direct the flow?

Course you could just buy more gas.

Pete

I used to have two welders--the H-F cheapie with FCAW, and the Hobart with a cylinder of C25.  Sold the H-F at a yard sale because I never used it after I got the Hobart.

Sounds like a fun experiment, but if you just want to make good welds, get more gas or use flux-core wire.

This is a fun thought.  I'm not a fan of flux core unless it's not a critical weld.  Flux ash makes a foamy weld with voids.

I'm trying to think of an aerosol that uses CO2 and doesn't have some hydrocarbon in it.  Cans of compressed air like you use to dust your computer are mostly CO2, but also have one or more of the "anes" in it - butane, hexane, propane to generate the pressure.  That wouldn't be a good mix for welding.

What about a can of CO2 from a Soda Stream?  Not sure how you'd regulate it.

Some of the air dusters out there are 1,1,1,2-tetrafluoroethane , which is R134a.  This is non-flammable at normal temperatures/pressure, but welding temperatures are definitely not "normal", so I don't think it'd be a good idea.

no, there would still be oxygen content in percentages high enough to be problematic. The shielding gas flows faster than it can diffuse into it. 

Also, water around an electrical welding process seems kinda dangerous to me.

I have no idea but I'm really curious about how one ends up with a windowed gas tight box with, glove openings and sealed pass-throughs for the welding cables and access to dry ice but no access to welding gas.

In reply to APEowner :

In theory you can do it with an open box and a chunk of dry ice inside. CO2 is heavier than air and will "Fill" the box with CO2.

We use such a process to UV cure epoxies so that the outermost layer does not react with oxygen and leave an oxidized  softer outer surface to the epoxy.

Pete

NOHOME said:

In reply to APEowner :

In theory you can do it with an open box and a chunk of dry ice inside. CO2 is heavier than air and will "Fill" the box with CO2.

We use such a process to UV cure epoxies so that the outermost layer does not react with oxygen and leave an oxidized  softer outer surface to the epoxy.

 

Pete

Hmm.  I didn't think about that.  You are correct.  I still wonder about a situation where it's easier to get dry ice than welding gas.  In some cases they come from the same store.

I doubt this would work well in an open box because the dry ice won't be outgassing fast enough to overcome the convection that will come when you heat up the CO2.    Yes, at room temperture CO2 is heavier than air, but if you super heat it by, say, melting metal near it with electricity, it will quickly start flowing upwards which will allow air into your box.

Now, if you had a sealed environment, then tally-ho!  That's called purging and it's common in industrial applications such as laser sintering/metal deposition. 

Friends don't let friends MIG weld with CO2.  Unless the metal is too thick for C25.

I migged for 3 years with nothing but CO2 and learned how to deal with it, even on thin gauge exhaust tubing and non-cosmetic autobody panel patches (floorpan, etc).  Then I tried C25, and I could not effing believe how easy it is. 

weldingsupply.com UPS shipped me a full 80cf tank for $233.

Don’t ever not try something just because the peanut gallery, who have no idea either, says it’s a dumb idea.  Who knows?  Small chance you might discover something.