Exhaust welding?

Hi
Not sure if this is the right place but..

I was cleaning/fettling the exhaust header off my DR350 when the end that go's into the cylinder and pulls up on the gasket fell off .

I now have to try to make a replacement 'Top Hat' section and weld on, trouble is: -

I will make the 'top hat' so that it will slide into the header a little to offer some support, it will be out of mild steel but I do not have a clue what grade the steel will be (just scrappy shite laying around). As it is going to be welded and I presume 'Tig' will be my best option as I require a small fine fillet weld, I believe that the quality of steel matters for welding using 'Tig'? I presume that if the metal was say 'Free machining' it has lead in it that does not weld well unless MMA or MIG is used?

Furthermore I do not know the quality of the metal pipe on the header, it is rusty but should clean up. It is relatively thin walled so again posing problems for MMA and I do not have room for this size of weld bead. I cannot really afford to feck this up so I seeking some advice.

1/ 'Tig' is going to be my best option right?
2/ Does the quality of the metal really matter, I have used 'TIG' myself many moons ago on Mild Steel and it popped and blew bubbles like I don't know what But I am not welder.
3/ My only other thought was to 'Silver Solder' the joint? Trouble is I do not know if the joint would take the temp range of the exhaust or the stress..all to often 4/ stroke exhaust can glow red hot now especially when trail ridden and stuck!

Any advice appreciated, once I have made the part to be welded I will probably be posting the 'Engineering services' section for welder .

Cheers

Adie

Not a clue to the answer, but Vern welded up a crack in my 100GS exhaust near to the hottest end.

I dont know where you are located but there is a firm on the Hixon trading estate, Stafford that makes exhausts, they made a one off downpipe for my trials bike out of stainless, did it whilst i waited, very reasonable at £60

ferret