I’ve cut a piece out of my rocker that was rusted. It has the little hump down the middle.
I kinda made a home made brake to do this but it’s left the what should be straight edges a little wavy. Piece is 23”x3.5” the wave is the 23” way. See pic.

How can I go about getting it flatter.

I tried clamping straight bars top and bottom that didn’t do anything. Hitting the highs down with a hammer doesn’t do anything either.

I suspect my home made makeshift brake caused the waves. I managed to tweak it a bit more and get it closer to flat anyway. Should be able to weld it in now anyway.

Should have spent more time on the brake ,probably would have done a better job.

Do you have a Low Crown Hammer?
https://www.youtube.com/@proshaper

You gonna make a Lot of Scrap pieces of sheet metal before you get it right with most patches don't be afraid of starting over.

Doright wrote:Do you have a Low Crown Hammer?
https://www.youtube.com/@proshaper

You gonna make a Lot of Scrap pieces of sheet metal before you get it right with most patches don't be afraid of starting over.

Thanks,I managed to get it pretty straight.Welded it in and looks good.This was towards the inside so its all a bit wavy anyway from the spot welds.