I tried searching the forums for the last hour for an answer to this question, but came up blank.
I need to repair cracks in the sheet metal on several tractors. I have a Lincoln flux core wire feed, with infinite adjustment on both amps and wire speed, so I can fine tune the weld I get.
I know to drill a small hole at the end of each crack to prevent further cracking.
On hinge points, I would probably clean up the welds, make a shallow V along the crack, weld, then carefully grind smooth. Then back up the weld with a non-galvanized washer, etc. welded at the pivot point.
Other cracks that cover a small area can be done the same way.
My problem is cracking around the seat holes on my JD 420. The cracks radiate out from each hole, and some of them are 3 to 4 inches long.
I'm thinking of welding up the cracks, then making a sheet metal stiffener that covers the whole area, drill the holes for the seat mounts, and put other holes in the stiffener to plug weld in several places, then stitch weld around the outside edge. I'll mount the stiffener on the underside, and round the corners a lot to avoid creating stress points. The metal I have looks to be a piece of 16 ga bare steel.
If anyone has experience doing this, or a better idea, please let me know.