Can You MIG Weld Stainless Steel?
Posted: November 28, 2018 By: MattM
We often get asked if metals other than mild steel can be welded with a MIG welder. The most common is Aluminum or Stainless Steel and if it can be welded by a MIG welder. Below we give some information about welding stainless steel with a MIG.
- Is it Stainless Steel or a Coating?- Often times coatings are put over steel to give an appearance of stainless steel and this can fool a lot of people. True stainless steel won’t be magnetic so you can test with a common magnet on the surface. If it sticks it is mostly mild steel, if the magnet doesn’t stick you’re dealing with stainless or another type of metal.
- Welding Stainless Steel- Any MIG welder that can weld mild steel can weld stainless steel. We do suggest to only use a true MIG welder and not a flux core as the shielding gas is very important when welding stainless.
- Which Welding Wire?- A little known fact is that you can actually MIG weld stainless steel with the same mild steel MIG wire you use regularly. The problem is that the weld will now rust and needs to be coated to stop rust. We suggest switching to a Stainless MIG wire.
- Use a Spool Gun- If you have a spool gun you can keep your wire in your welder and switch out the stainless wire to the spool gun to save down time on the welder. Load it up and set the machine as you would normally.
- Back Purge- If you’re welding stainless tubing we suggest to look into purging the backside of the tubing when welding to avoid contamination to the weld. This can be done with something as simple as a hose fitting T and some tin foil with a hose run inside the tubing to fill it with welding gas as you’re welding.
- TIG Welding Stainless Steel- If you’re doing a lot of stainless steel welding we do suggest to consider switching to a TIG welder for those jobs. A MIG welder works well for occasional stainless repair, but it tends to be a messier finish and isn’t as controlled on thinner gauge metal.
Most welding supply stores will carry or can order stainless MIG wire. You should try and match your filler wire as closely as you can to the type of stainless that you’re welding. To see our entire line of MIG welders and accessories visit Eastwood.com today.