Welding Tips and Tricks

As the title describes, I am welding 304 Stainless .065 tubing with back purge. My question is how to control the distortion (low areas) on each side of the weld. This particular customer requests that I sand the weld smooth for polishing. That creates problems with the low areas.
Thanks in advance for any help.

Welcome to the forums
Can you provide more info? Such as are you using filler and what is the amperage. Honestly you shouldn't be getting "low" areas, so it sounds as though your not using filler. Post a photo if possible

I just did some .065 SS tubing and I pulsed it but your post is a bit confusing...can you elaborate?

I'll assume no filler, full pen since you are back purging. I use 45-48amps straight, 1/16" tung, large cup and gas lens. I also pulse 2.5pps 50% on 50% 55-58amps 1/16" ting gas lens large cup.

Here one polished with an ultra fine scotchbrite belt

Thanks for the help. I will get a couple of pictures up to help describe my issues.

This is pretty typical of what I am getting. Usually one side will sand down fine. Filler is 308/035 @ 40 amps

I see what's going on. Mainly because I'm guilty of making the same mistakes

You're not lining up the tubes axially. One tube is off to one side by a few thousandths. It's not distortion that is causing low areas---the tube itself is low to begin with, on that side.. I've drawn a red line to illustrate:



The solution? Either continue grinding that area carefully until it appears properly blended. The right thing would be to get a better fit-up so they are dead-on axially.

I see the same thing as Oscar, alignment and fit up is key. Is what I showed above not acceptable? If not you could sand that area down and feather it out, I have a specific machine that wraps belts around tube, makes life easier.

What did you end doing?

Better alignment seems to be my problem. I have started to take a considerable amount of time up front making sure my fitment is the best it can be. I would say 90-95% of my problems have disappeared. Thanks to everybody that took the time to reply to my post!

MadisonRods wrote:Better alignment seems to be my problem. I have started to take a considerable amount of time up front making sure my fitment is the best it can be. I would say 90-95% of my problems have disappeared. Thanks to everybody that took the time to reply to my post!

Fade out to stop those craters, which are crack generators and can be tight leakers.