Welding Tips and Tricks

Quick question: What would be a good stainless steel filler rod for regular steel exhaust pipe? Or should I stick with er70s2? Thanks!

Blaze659 wrote:Quick question: What would be a good stainless steel filler rod for regular steel exhaust pipe? Or should I stick with er70s2? Thanks!

309 is more forgiving in my opinion.

ER70-S2

Well.. That got a nice consistent answer!

Both will work. The choice will probably depend more on the expected lifespan of the system.

If it's a good system made from aluminized steel that needs to last for years to come then perhaps do it with 309 to get decent corrosion resistance in the welds. (often the welds are the weak spot in these systems and they rust out soonest)

If it's a system that's already plain mild steel or one that just needs 'a fix' then er70s2 is fine.

BTW.. Some systems can be 409 stainless although it can be tricky to spot as it does tend to get a surface rust coating and it is magnetic, so often mistaken for mild steel. 309 works fine for those of course.

Bye, Arno.

Thanks fellas! Would the 309 require purging to stay strong or would it be fine without for standard exhaust pipe?

Blaze659 wrote:Thanks fellas! Would the 309 require purging to stay strong or would it be fine without for standard exhaust pipe?

The ideal way would be to purge if you can, make sure the joint is free of all contaminates (ID and OD), clean back a good 3/8" from the joint.

Could a purge be made with exhaust gas? The other end might not be open or accessible , exhaust wold keep out most of the oxygen. Just askin.........

mcostello wrote:Could a purge be made with exhaust gas? The other end might not be open or accessible , exhaust wold keep out most of the oxygen. Just askin.........

No the gas(in this case argon) needs to be inert, meaning it won't react with the molten metal