Welding Tips and Tricks

I have been around welding all my life(58yrs), have worked in the oilfield ever since high school except for about 3 yrs when I worked at and owned a small welding shop. In that time I have never seen or even heard of welding anything with a backing strap. Now with the internet I see videos of people doing welding test with them all the time. Where are they used in real life. I mean are they left on when the weld is done or are they cut off some how? If they are removed why the heck use them to begin with.
Just a little insight would be appreciated, Steve

Permanent backing bars are common in pressure vessel manufacture for one.


Sent using Tapatalk

A common joint on tanks that forms a backing bar is called a joggle joint. Where one of the pieces, has a edge bent on it to slide inside the other piece. this forms a backing bar but with one piece. It's how they make propane tanks for cars. I have also seen a 10mm thick on that was for a propane transport truck.

Also any number of structural stuff. The bars are usually only removed on test pieces so they can check if you have done it right.

Thanks guys

Often used in heavy structural stick when there's a gap too wide to bridge. Traps the root. Then the backing is cut loose, and covered from that side. May even be gouged then filled and covered.