Stainless Steel

[Merv]

Hi! What a wonderful site! Just ordered 12m of polished 316 grade Stainless tube. The size is 25mm o.d. and wall is 1.5mm. I have also bought some 316 mig wire and some argon gas.

I have done some welding in the past but never on stainless - any tips, useful websites, etc? Specifically - is it just like welding the same thickness in mild steel?

 

[Hitch]

Not to much different. You might find you get a little more spatter, some anti spatter will help with that.
Another downside to welding ss, is it will distort more than mild. Take your time setting up the job, and clamp down or to something whenever possible.
The other thing to remember, now you have gone to the trouble of getting 316ss tube, when you come to weld, dont just stick your earth clamp on it, or plonk it on a steel bench to weld, use some ss scrap between the earth and job or you will get contamination.

 

[Merv]

Many thanks for those tips. I knew about the distortion but never thought of contamination from the earth clamp and bench. The tube is pretty expensive so the fewer mistakes I make the better. Cheers!

 

[malcolm]

Hi Merv, welcome to the forum.

By strange coincidence I did a little 1 inch stainless pipe welding this weekend. A friend has been redesigning the cooling system on his Davrian.

He came up with a really handy jig to hold two bits of pipe end to end and keep them straight:

The jig was held together in a G clamp, and the cutouts were big enough to tack the tubes together. It worked really well:

Also for a bit of fun we modified the header tank. It is a horrible piece of work made from 2mm stainless sheet. We cut it in half and welded the end back on to help with packaging, then added the inlet and outlet pipes:

 

[Merv]

Brilliant images Malcolm!

The jig looks useful.

My boat is currently in Greece and is badly in need of some care and attention. The plan is to make up a variety of deck gear in stainless during the Winter and then drive out there next Spring.

Meanwhile I am helping to build a Banham X21 - now that really is a problem! Cheers.

 

[Nial]

He came up with a really handy jig to hold two bits of pipe end to end and keep them straight:

The jig was held together in a G clamp, and the cutouts were big enough to tack the tubes together. It worked really well:

Brilliant Malcolm, I'm sure that'll be useful in the future (if I remember
about it).

I made a chopper bicycle a couple of months ago from two old frames I
got from the dump, mainly as more welding practice. Trying to get the
fork extenders lined up to weld them was a real pain, they're _mostly_
straight now. That sort of clamp would have helped a lot.


Nial.

 

[Hitch]

All i usually do is just sit each end of the tube inside a piece of angle, tack, tack, turn tack. Job done :idea: