Page 1 of 1

Different mixes

Posted: Wed Sep 28, 2016 1:57 pm
by Icr242005
New to this forums and welding. After tons of research, I have not been able to find any info on this. Hobbies at best but don't want to keep 100 bottles in my garage(nor want to spend the money) so here is my question. There is a ton of defferant way to buy/use gases like CO2, 80/20, 75/25, argon straight Ect. I will be doing some car sheet metal, aluminum and occasionally 1/4 steel. Is there a gauge that will allow me the buy a bottle of straight argon and straight CO2 and mix them as I need. So if I need 80/20, I can set gauges accordingly and then if need straight set gauges accordingly ? My welds will not be tested, seen or put on anything that a perfessional needs to do. Thank you.

Re: Different mixes

Posted: Wed Sep 28, 2016 7:19 pm
by Otto Nobedder
For plain MIG on mild steel, you only need one bottle.

For pure economy, you can do 100% CO2. For smoother welds, choose either 75/25 or 80/20. In short-circuit transfer (light body work), you wont notice any real difference. The 80/20 gives you the opportunity to spray-arc, if your machine has the gonads.

CO2 is a fine choice for body work because it is very economical and you will be grinding/buffing welds anyway.

75/25 is a general-purpose gas that will do everything you want in body work AND give good results on heavier sections (like frame repair/modification).

80/20 is not something you're likely to need until your experience progresses and you FIND a need.

Steve S

Re: Different mixes

Posted: Wed Sep 28, 2016 9:17 pm
by Icr242005
Thank you. That helps me out a lot. Little are not cheap now days. It's been awhile since i have checked the prices on tanks and wow they have went up

Re: Different mixes

Posted: Thu Sep 29, 2016 2:06 pm
by billdacat
20 lbs of CO2 goes a long way. Since it is a liquid, it evaporates to make 175 cu/ft of gas or about 8.75 hours of weld time. (20 CFH).

Re: Different mixes

Posted: Wed Oct 19, 2016 5:01 pm
by notabiker
http://www.weldreality.com/MIG_welding_gases.htm

Someone has done a lot of research on this and this is a long but good read with lots of information.

Re: Different mixes

Posted: Wed Oct 19, 2016 6:19 pm
by Otto Nobedder
notabiker wrote:http://www.weldreality.com/MIG_welding_gases.htm

Someone has done a lot of research on this and this is a long but good read with lots of information.
Welcome aboard!

That's not the first time I've read that.
Like many things on the internet, there's a mix of truth and self-aggrandizing bullshit.

Yes, production speed and economy can improve in a production environment with 98/2, 90/10, and 80/20 mixes. Yes, output can meet the code requirements.

That said, I have rare need of spray transfer with carbon steel, and if I do I'll use my helium tri-mix. Spray on 304SS is also easily accomplished with tri-mix.

Why do I use 75/25 and the Helium tri-mix (90/7.5/2.5)? I do repair work for the people who make these gasses on the vehicles that transport them as cryogenic liquids, and I weld to their specifications. I get these specifications from their engineering department, not their salesmen. That has to have some merit, as they are profit -driven and would not intentionally overprice an item in their own WPS since we are selling their own product back to them in it's use.

Steve S

Re: Different mixes

Posted: Sun Oct 23, 2016 4:04 am
by tberg
Not sure I should be the one to listen to on this but after talking to my welding supply guy I went with 100% argon and a 75% 25% just so I could do aluminum and steel. I'm new to welding and just going of what he said. Good luck I know I'm going to need it.

Re: Different mixes

Posted: Mon Oct 24, 2016 11:23 pm
by Otto Nobedder
tberg wrote:Not sure I should be the one to listen to on this but after talking to my welding supply guy I went with 100% argon and a 75% 25% just so I could do aluminum and steel. I'm new to welding and just going of what he said. Good luck I know I'm going to need it.
100% argon will do MIG aluminum and TIG almost anything, and 75/25 will do low alloy carbon steels and most higher alloys, so you're good to go for almost anything.

Steve S