Choosing between a 3/8 inch and 1/2 inch backing bar for the new tank in Toledo

We were welding up a big pressure vessel for a client in Toledo and had to pick a backing bar thickness for the root pass. I went with the 1/2 inch bar instead of the 3/8 inch because the plate was a bit warped from the fab shop. It gave us a much more solid base and the root came out perfect with almost no cleanup. Anyone have a different go-to for dealing with warped plate on a big seam?

3 comments

3 Comments

benlewis1mo agoMost Upvoted

Man, I feel you on that. Warped plate is the worst, it just throws everything off. Good call going with the thicker bar. I've been there trying to chase a gap that just won't sit still, and that extra mass from the half inch just makes it so much easier to get a stable setup. Solid choice for sure.

gonzalez.vera29d ago

That "gap that won't sit still" reminds me of trying to level my grandma's wobbly kitchen table last summer.

benlewis22d agoMost Upvoted

Totally, that extra weight just kills the vibration. I used to shim a warped base with folded up sandpaper under the low corners, but it's a pain. You end up adjusting it every time you use the tool. @gonzalez.vera's table story is the same deal, just on a bigger scale. A solid, flat mounting surface is everything for keeping your cuts or your measurements right.