Can Stainless Steel Muffler Be Welded With Oxy Acetylene Torch

Question:

This muffler says it stainless steel. Does that mean I cannot weld it to my steel exhaust pipe using an Oxy acetylene torch with steel welding rod? Thanks,

asked by: Bill R

Expert Reply:

The MagnaFlow Stainless Steel, Straight-Through Universal Muffler, part # MF12615 does state it should be welded for installation. From my research I found that you can weld stainless steel with an Oxy acetylene torch, but it may be tricky. If it is not done correctly I saw where many people say the weld will look like it is charred or burnt.

From what I found there are steps to take that will produce good results. First, you need the right flux and it should be used on both the parts and the welding rod. Use a tip on the torch the same size as the rod or 1 size smaller, and make sure it is clean that will provide a nice flame. Use a neutral to a 1x reducing flame. Bring the torch in fast, and start the puddle with a steady motion. Filler should be kept on the outer edge of the weld letting be 'drawn in'. Progress the weld with a steady torch, letting the weld grow on its own, and draw the torch off slowly when finished.

If you need to stop and re-start a weld, you will need to apply flux to the area where you stopped.

Some things mentioned that should not be done are:
Flicking the torch in and out of the puddle
Dabbing the filler in and out
Torch circles
And an oxidizing flame.

I hope this answers your question. Good luck with the weld job.