Thread: co2 for mig welding

Hey Tom,

Yes we use Co2 for Mig welding, with flux cored wire, and yes we also use a Heater/Regulator, its a bit more forgiving.

HazzaB

can i ask why you use flux cored wire with co2

thanks
tom/WODSTOK

Hi,
Welcome to the mob
Co2 on a home based unit is not very efficient.

Its is basically a less expensive gas used by some operators willing to accept less than optimum results in their home welding.

Most ,I daresay, utilise their Mig for its ability to weld thin materials and in multi positions.

Co2 causes the arc to penetrate the metal extremely deeply and is excessively hot making it unsuitable for light sheet and too hot (and runny) for positional work.

I used it in industry for heavy deposition work with flat position only.Its very specialised in the application and not suited.It needs a heated regulator as the gas passing through the reg it will freeze the innards of a non heated unit.
With out a heater ,it will drive you nanas on a job waiting for the bastrd to thaw.

It has not been mentioned many times at all over the several years I have been a forum member.

Hopefully you only making an enquiry prior to a purchase?

Grahame

i will only be using the gas for home use. i will need th build a fence out of 4x25x25/4x20x20/4x50mm so i think that it will be fine for my job?. i just dont want to pay bottel rent ($165 a year for an ''E'' size bottle) when i can buy a 2.6 kg bottle of food garde co2 outright for $220 +/- and swop it over for $30 +/- at my local home brew shop.(mum was very happy when i said that could buy a bottle outrigh and not pay $165 a year)

thanks

tom/WODSTOK

Wodstock,

My opinion is that given you want to weld 2 mm wt sections with Co2 you are headed for grief for all the reasons given previously.

With the fluxcore that HazzaB uses ,I'll bet it is on thicker section than 2mm.

If sections are gal coated even more grief and the light wall and gal react badly with the welding arc.

Grahame

thanks alot for your help i think i will de going for the argosheild

thanks

tom/WODSTOK

In the UK around 25 years ago, BOC gases had the monopoly on Argoshield and it was both expensive and the rental virtually non existant to private users.

I had a SIP 150A compact mig and used it constantly on beer gas (Co2) I used a standard beer gas regulator (supplied by my friendly local pub) and had no problems whatsoever with freezing of regulators even in the uk's colder climate.

Ok I only used it for home use, renovating rust damaged classic cars, and my welding consisted of maybe 2-3 hours per weekend max. Most welds were short runs and "stitch" type repairs, but on fairly thin sheet materials.

I note the weld was yes, a little hotter, and there was more splatter, but not excessive.

Don't want to create a bun fight here, but just for home use it can be done and at minimum cost
.
I have just returned my BOC "E" size cylinder here in Perth, and am currently looking again at CO2 as a cheaper alternative for minor repairs and general stuff around the home.( I have only used one fill of Argoshield in 3 years since retiring ) and the annual rental now is becoming just too prohibitive, for me anyway.

Brian

Hi hazo,
I not looking for an argument either ,but I advised Wodstok about Co2/argo
sheild gas on the basis of :

• That he is a young fella (14yrs) and is likely not to have the welding background and experience behind him to "tune in" a new machine and gas system.
  
• The material he is using for his fence is RHS box section and has a very thin wall thickness and little volume in the metal mass to dissipate the extra heat generated as a result of using Co2.
  
• Given that the stated application of the project is fencing it is reasonable to assume that the material finish is galvanised and that again imposes another layer of difficulty on the outcome of the project.

While I am aware that it is possible to do as you say, a 14 year old is in a different position to a mature adult and will have a greater degree of difficulty in managing the process new to him.There's tricks you could have used (copper sheet backing for example that ere not feasible on his project.

I would hate to see Wodstok give away welding /fabrication becuase of a bad experience first up.Accordingly I advised on the basis of best success. As a former Tafe teacher and presently high school Vet Engineering Cert 1 studies instructor, I am here, among other reasons to promote welding and metal fabrication .
Its important that a student is supported and given the best opportunity to be successful at their first project.

I am aware that hire of shielding gas cylinders costs.-well aware, as I hire argon and argo shield cylinders myself.Its a question of how well you want to do the job.
In any case it seems as Wodstok has some ideas on a side business to generate an income to support his metalwork - see his posts in the trailer section-To cut a long story short it appears he is looking at small metal sculptured figures-desk ornament knick knacks made from bolts,nuts wire and washers.
These units would sell because of style and appearance - my opinion is that he won't get the finish appearance from using Co2.

Unfortunately there are not enough students genuinely engaging in the subject with the view to gain an apprenticeship or as a grounding for and engineering course.For those who show an interest ,I will support in any way I can.

Given that you and Wodstok both reside in Perth is it possible that you may be able to assist him with some hands on? When your learning it sure is handy to have someone who has the experience to assist.

Grahame

For a little one off job like a fence I would just use flux core wire. Its not as nice to use and the results aren't as pretty but its a lot cheaper than paying for a cylinder you rarely use. I've used flux core successfuly for the last 3 years, the biggest thing that ##### me about it is the fumes. You definetely need to wear a P2 mask when using it.

I have started getting my wire from weld smart in canningvale. The wires a lot cheaper than a boc and seems reasonably quality. Its about $80 for a 5 kg spool.

Hi Grahame

Sorry if it appeared that I was undermining your opinions, I was merely stating that with a little extra care and a slightly different "learning curve" it can be done. And with quite acceptable results.
And I personally did not have any problems using the co2 as a shielding gas and regulation.
But I did learn on Agoshield primarily.

I appreciate that for a young bloke it would be better to follow the tried and tested methods.

If Tom/Wodstok were to contact me I would willingly give any help or advice I could.
I live in the Northern suburbs of Perth.

Brian

thanks heaps for all your help i have been welding with two migs on 2x20x20mm angle iron and 1.6x20mm flat bar with co2 in my mig and migsheild m1 (air liquid) in a 190 amp 3 phase mig and the only dirrerance i could find wans it burned hotter but i didnt blow any holes in my work

thanks tom/WODSTOK

Originally Posted by wodstok

can i ask why you use flux cored wire with co2

thanks
tom/WODSTOK

Tom,

Majority of flux cored wires still require a shielding gas. CO2 was likely the specified gas shield by the wire manufacturer.

Excellent Tom.

My experience was with a low end SIP machine and a disposable cylinder.My mate (and I ) had a lot of trouble with that one.

I am glad it was different for you and it looks like I owe Hazo an apology as I was wrong.
Maybe he can assist you as he lives in Perth too.

If you are happy with it you should go for it then.

Grahame

hi grahame i welded for 20 years in heavy ind.i found co2 with a heater very good to weld wia 380 amps.for memory i think i used argoshield 54 on 2mm and under john T