welding a boss onto a mild steel downpipe

[druist]

i have a lambretta which i am customizing to a race spec. Before I have a stainless exhaust and a mate tig welded a receiving boss on which was also stainless.

Now i have bought a mild steel exhaust as problems with 2 stroke and SS are common.

All i need is a nut with the right thread, but now all access to is my 135amp turbo mig clark. now the problem is i dont know what metal most nuts are? Obviously many are stainless or alloy. I only have standard wire .8 and .6
though i do have some argon/co2 bottles.

Any ideas on what nut (material-wise) will be ok, or if there is another way?

thanks

 

[pedrobedro]

Just buy a mild steel nut (not stainless) the right size which you will know to be mild steel. If it is zinc plated you could grind it off but personally I don't bother as the coating is microscopically thin. Put a bolt in it before you weld it to protect the threads and just get on with it your welder should be fine.

 

[druist]

thanks Pedro