crack repair

[Ram48]

Well I have my first red cross repair job for the local High School where I coach. One of our head coaches caught a fence post with a John Deere greens mower and bent and cracked the 1/4 inch thick steel bracket that holds , raises and lowers the rollers. I was able to get it back in alignment with my press, a little heat and a BFH
My question is how best to weld the crack. It is tight fitting now so I am going to grind it out some on both sides and drill a hole at the base of the crack. At least that is what I am thinking, but please let me know if I am on the right track or if there is a better way to repair it. It is a close fit so I can't use a reinforcement plate on either side.
Thanks
Ray

[dirtyfarmer]

Ray,
I would have thought someone would be all over this, contest count and all. LOL
Your plan sounds good to me. Just be sure to use enough fill, and amps on both sides, so you can grind it flat afterwords with minimal gouges left. Should be good as new.

[jakeru]

If its clean inside the steel crack, and you've got a TIG machine with enough power, no need to vee it out. Just hold a tight arc, and use plenty of power, to penetrate deeply. Even some high speed pulse (DC welding) could be helpful to concentrate the heat better and penetrate better. Welding on both sides, all you need to do is penetrate at least 50% on each side and you'll have full penetration weld. Use a little bit of filler rod to avoid undercutting, but probably not much needed on a tight fitting joint.

There may be a direction that is more desirable to weld - (welding towards or away from the beginning of the crack) but I can't really say which is best or if it matters. Keep in mind that welding will cause tension/contraction/"pulling" forces though. If you had a gap that was a little wide at the open end, you could tighten it up by sequencing your weld to begin at the beginning of the crack (where it is tight) and as you welding along the joint, the cooling weld bead would tend to pull the pieces together into alignment.

If the pieces of metal are in perfect alignment, do a few good, deep, high heat tack welds first to keep them right there. "backstepping" can also minimize distortion (where you weld it in short "stitches", and move the torch when the arc is on, in an opposite direction as when the arc is off.)

Attached pictures are example of backstepped, stitch welded steel joints I made (to keep pieces in alignment and reduce weld distortion.)

[Ram48]

Well I did get it finished and back on the JD greens mower. So far so good it has cut both baseball, football and softball fields twice and looks fine