While stainless steel is made up partly of mild steel it also has other properties in it’s molecular makeup that make it different than just mild steel you find anywhere. Because of that you may need to get special supplies when welding it. Below we cover a few tips for choosing shielding gas and welding wire.
- Match Your Welding Wire- As a rule of thumb you should try and match your welding wire as closely as you can to the stainless that you’re welding. Most raw pieces of stainless are etched or stamped with what grade stainless they are. Some are “softer” while others are more brittle and this can change how well they weld. If you match the numbers of your stainless filler wire closely to the stainless itself you will have the best results. When possible avoid welding stainless with mild steel welding wire. Stainless can be welded with standard mild steel welding wire but keep in mind the weld itself will rust over time.
- Best All Around Stainless Welding Wire– We’ve found that 308L is the most common and easiest to use Stainless welding filler wire. It works well with most types of stainless and wets out well when doing repairs. We’d suggest this filler wire for most general repairs or fabrication when welding with stainless.
- The Best Shielding Gas For Stainless Welding- Whether you’re welding with a MIG or a TIG we’ve found that 100% pure Argon is best for welding stainless steel. If you’re welding tubing or metal that may be exposed on the backside when welding you may want to “back purge” the backside of the weld with Argon to keep contaminates from getting in the weld from the back. If you’re welding stainless tubing you may want to block the ends of the tubing off and fill the tubing with argon while welding. This will help tremendously with the quality of your stainless welds.