I'm getting some conflicting information here, so i turn to you guys to set me straight. I have a small Lincoln 110 MIG (well, flux core for now)welder that I picked up with the intention of doing some small jobs. My question is this, what gas or gas mix should I use for thin sheetmetal? say 18-20 Ga.? Simple question, but since it's beyond rivets and bondo, it's out of my league...
I do collision work for a living and when welding mild steel I run 75/25 argon/c02 (c25 is what it's called IIRC). When doing aluminum it's 100% argon. If you do stainless steel run a trimix, I run 90% helium, 8% argon and 2% C02, as it's what my local welding supply house recommends -and has worked well for me in the past - so why change?
I've got the same machine...small Lincoln..that I converted to gas...works great on light stuff...better than my big Miller...But I've been using straight co2...first 'cuz I'm cheap...second 'cuz I've got a small bottle from an old beverage dispenser that was full of co2 and I don't like to throw stuff away so I use that...for now...but I do have a new 75/25 gas bottle ready to go...C25 welds are prettier...regular co2 works good...
Krozzer has the idea ,it's not hard to come up with a fountain pop cyl. to save some $. It may not be quite as good looking weld but most will never know the difference. There are a lot of those small wire machines out there, you can cheat the amperage a little by going to the smallest wire. Every time you use a bigger wire the available amps is reduced. Best of luck.
depends really what your weldin ? if ya don`t mind a little splatter and or are goin to grind after use straight co2 it is less money and does as good of job for the most part . and is alot less slpatter then flux
You can add a 5" diameter 120V AC muffin fan to keep the transformer cool and increase your duty cycle 10-20%. Set it up to draw cool air into the case and blow out the back/top thru the fan. Several MIG's on the market simply use a fan to offer higher ratings from the same package and charge a hefty increase. 25/75 is basic entry level gas mix for sheet metal; 30/70 or even 40/60 if you are after top quality and workability.