Welding Tips and Tricks

While I understand that stainless is best welded with as little discoloration as possible and sugaring is always bad, do they mean the weld is beyond recovery?
Can grinding them off to bright metal and polishing regain the stainless quality?
Does sugaring mean the entire weld now suffer from a chromium deficiency?

Mark

mpete53 wrote:While I understand that stainless is best welded with as little discoloration as possible and sugaring is always bad, do they mean the weld is beyond recovery?
Can grinding them off to bright metal and polishing regain the stainless quality?
Does sugaring mean the entire weld now suffer from a chromium deficiency?

Mark

And the answer is.....
http://www.epri.com/abstracts/Pages/Pro ... 0001009717

And....
http://www.weldingtipsandtricks.com/wha ... lding.html

Thanks for your help
The epri web page gives interesting reading and I hope the last paragraph gives me at least hope, that the contamination does not go through the entire weld and can be dressed down.

I am still new to TIG welding but I am improving just not there yet. Hopefully soon these concerns will be a thing of the past.

Hello Mark
Is this just a general question or do you have a specific "something" you're welding and dealing with this issue? If so a photo would be helpful.

Sugaring is often referred to the back side of a weld that wasn't purged, the top side can appear normal and you wouldn't know any sugaring occurred unless you view the backside, this doesn't necessary mean the weld is bad unless you're welding to a code or specification that requires a back purge.

If this is a personal project then more likely the weld is good, again more specific information is needed to say for sure

It's more of a general interest question.

I have nothing at this time that I am worried about, but, with my general skill level it might pop up

If you weld on any stainless and get enough heat or penetration to the backside with out shielding it, or having a backing plate it will "sugar".

I weld stainless steel exhaust tubing now and then - 1mm or less thin so complete penetration is the norm.

I can't always back purge but I also can't afford sugaring as this would potentially weaken the inside of the joint in a weld in a high vibration application (motorcycles.)

I have used Solar B type flux with some success. It leaves a glass-like residue on the inside of the tube which is of no real consequence in this application and indeed after some use it usually comes off (I expect through heat cycling and vibration) to reveal a nice backside of the weld with no sugaring.


Kym