Stainless steel motorbike exhaust

May 17, 2004 3 Replies
S

Hi,



I have a crack in my stainless steel exhaust (due to the bike falling over) which I need to weld over. Pic here:

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Unfortunately I know very little about welding, and absolutely nothing about welding stainless.



I have a MIG welder which I use for bodging plates over rust holes on my old car, but I am self taught so don't have much knowledge. I have a big bottle of CO2 pub gas which seems to do the trick and a small bottle of argon. The wire I have is 'normal stuff' for normal metal.



So, what do I need? There will be no major stress on the weld, so a bodge will be fine (the crack has been there relatively unchanged for 3 years now). I assume I need some special wire? Do the same rules on power and wire speed apply? (Hmm... I don't really know the rules for normal metal!)



Ta for any help, Steve



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E

A TIG welder, 3 months of practice with supervision, some 321 or 347 SS filler rod.

If you insist of MIG welding it, buy a small spool of 0.030" 309L wire, an rent a small bottle of helium tri-mix from your supplier.

Keep your wire stick out extremely short, and run your power and wire a little higher than you would for steel.

>
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S

Ah... you imply this isn't easy!

What's this wire? How does it compare to my ?0.8mm 'normal stuff' What will happen if I just use my CO2 (or Argon)?

I already have the welder set on highest power for most of what I do. I was expecting to have to turn the power down if anything.

Steve

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E

It just takes some practice to do it clean.

309L is the best alloy of stainless steel filler wire to use when you are not sure what your base metal is.
0.8 mm is aboutthe same as 0.030 inch wire.

Very nasty dirty welds, and they will likely rust a bit.

Stainless steel is a terrible condustor so you have to boost your heat to get the same power through it.

You might want to go down to a smaller wire, like 0.6 mm (0.023 inch).

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