Welding stainless steel

[rwm]

This might be a dumb question, but some of your weld zones look etched beyond the weld. You are not on AC are you?
Robert

 

[brino]

Great question Tim!
I am glad you're not too proud to show your fails.

Thanks everyone for some great tips and discussion.
With my day at work dealing with detailed emails and spreadsheets it good to have something interesting to read!

I have learned something today.

-brino

 

[Just for fun]

This might be a dumb question, but some of your weld zones look etched beyond the weld. You are not on AC are you?
Robert

Nope, I'm on DC.

 

[Just for fun]

Great question Tim!
I am glad you're not to proud to show your fails.

Thanks everyone for some great tips and discussion.
With my day at work dealing with detailed emails and spreadsheets it good to have something interesting to read!

I have learned something today.

-brino

Thanks, Glad I could bring some entertainment to your day!

You never know unless you ask.

Tim

 

[Just for fun]

You may be welding with the amperage too low.

Welding "cool" makes you stay in one place longer waiting for a decent puddle and end up pumping pump far more heat in than you would if you'd had more amps and worked faster. Moving quickly is so, so important when welding thin stuff, but it's not easy! MIG with stainless wire is much easier to get a decent joint and not cook the other side (without back purging), for what it's worth.

Thanks for the tip. I'll get another piece cleaned up, turn the heat up a bit and try and go a little faster. Backing it up with a piece of aluminum helped.

 

[brino]

Backing it up with a piece of aluminum helped.

A copper backer may be even better.....

 

[rwm]

Tim- I was specifically looking at this pic:


Those welds on the left have a funny zone around them and the bead has a dark appearance. Do you purge your torch before the first weld? Could the gas flow have been too low? Could the metal be clear coated that you don't know about? Any chance the material is 303 SS? (Which doesn't like to be welded due to Sulfur and Phosphorus)
The back side it always and issue if you get full thickness penetration. For cosmetically important welds I try not to do that. I also will clam a flat piece of steel on the back sometimes. Copper is superior but expensive.
Robert

 

[Just for fun]

Robert, I thought maybe that is what you were looking at. Those welds on the left are the back side of the first pics I posted and what made me ask the question to start with. I flipped it over and clamped it to a piece of aluminum to do the next two little beads. I don't have that much of the stuff, so I don't want to waste too much until I finish the cup holder for my wife's ATV. LOL

I have no idea what the material is, it was in the junk pile.

 

[rwm]

Ahhh. Makes sense now.
Robert

 

[Just for fun]

Ok, I've been playing around with that piece of stainless. Clamping it to a piece of copper really helped and so did turning up the amps and moving faster.

Thanks for the pro tips!

Anyway I started with this:


And ended with this: