tig welding EMT

By Lawrence (*****)

Date 07-23-2007 23:11

Tig requires the most surface prep of all the processes when dealing with zinc coatings..... You will need to remove ALL the coating before you weld, trial and error will show you just how clean the surface prep will need to be.

I don't think galvanized coatings would last long in a tail pipe environment. But the plain steel lasts for years anyhow eh?

By DaveBoyer (*****)

Date 07-24-2007 03:51

The galvanizing might burn off close to the manifold, depending on how hard You press the engine, but further back in the system where the water vapor condenses out of the exhaust and rust is a bigger issue the galv. will be there to help, except at the weld joints. The lower sulpher in today's fuels will make it last longer than it would have years ago. It might be easier to stick weld than to get it prepped well enough for a good TIG job.

By Tommyjoking (****)

Date 07-24-2007 06:18

As already said you will have to do quite a bit of joint prep to make tig welding this work. A more important factor is safety.....Tig welding means your close...you need to provide a fan or somthing to pull fumes away from you or you will get really sick. Burning zinc causes a poisening of the blood when inhaled....its hard on your liver among other things. A dust mask wont help. If you feel ill whilest doing this job discontinue the work and drink a lot of whole milk and it will help. Now after all that .....considering the thickness, metal, and coating of the emt....I don't believe it will be a long lasting project....EMT is not exactly designed for the repetitive heating and cooling or the corrosive gases your going to put thru it. But sounds like a low cost exhaust...... If you want to weld it without joint prep go to your welding supply and ask for a 1/16 "sodell" rod. (I think its a specialized 6010). you can weld up very thin galvenized with this without too much effort.