thick to thin

[WORZELGUMMAGE]

hi
i have been learning tig welding for a couple off months now, on ali, not doing to bad, but when it comes to welding something thats thick to thin i am struggling a bit. say like 4mm with a 1mm tube on top. would appreciate
any help.

thanks dave..........
these are stainless steel exhaust manifold for a da 50 engine for model plane.

 

[Shox Dr]

If they can be welded from the inside, and the fit up is good enough to be autogenously welded then a very sharp 1.6mm or 1.2mm tungsten (insert favourite colour) with 60-70ish amps wash it in with a 1.2/1.6m rod in hand just in case

 

[langy]

Start on the thick material and keep the arc length tight, I encounter this a lot when making manifilds, I also like to use 1mm rod, I use like to weld the flanges on the inside.

 

[WORZELGUMMAGE]

thanks for the replys. will try inside without rod, just to hold it, then im going to silver solder it.

cheers..........

 

[langy]

thanks for the replys. will try inside without rod, just to hold it, then im going to silver solder it.

cheers..........

Why silver solder ???

 

[WORZELGUMMAGE]

Why silver solder ???

if it was 4 my self i would chance it but its for a mate. at £8.00 for a bit off pipe, can get expensive if i knacker it up

 

[langy]

if it was 4 my self i would chance it but its for a mate. at £8.00 for a bit off pipe, can get expensive if i knacker it up

If you get a nice fit autogenous weld is pretty simple to do

 

[Lawnmowerboy]

I would have said an autogenous weld is easier than getting a nice silver solder joint and being able to guarantee no flaws in the solder joint ect.

 

[WORZELGUMMAGE]

I would have said an autogenous weld is easier than getting a nice silver solder joint and being able to guarantee no flaws in the solder joint ect.

it prob would be if you did it but not me. im going to see if i can find some pipe the same thickness, and have a try. will post some pict if i get the chance.

thanks......

 

[Lawnmowerboy]

The hardest bit is getting the pool going and joined up. Just keeping a very tight arc gap and strike up on the thick bit and the thin bit should melt into it. If it doesn't then very briefly wash up onto the thin bit but it should take enough heat from the thick part to get going.