welding on a rim

What I would do is to clean the area to be welded then tack weld the cracks about every 2", about 1/4" to 3/8" long, then take a cutting torch and start heating the crack area starting at the stem hole working your way to the end of the cracks. Work to apply a fairly even heat along the entire area about 1" wide or so. The pre-tacks hold the metal from off-setting when you heat it. I always tack weld about 20amps hotter than I weld at.

Want you want to end up in the heat zone is a very dull red color but you want the red to start at the stem hole and work towards the end of the cracks. This will stress relieve this area so it won't recrack latter on. A rose bud will apply too large of a heat zone.

Once your stress relieve, let the area air cool, then prep the cracks,"V" groove slightly, then weld from the stem hole outwards.

I like the idea about drilling a new hole. Great idea. To fill the old hole just clamp a piece of flat copper on the non weld side then fill the hole with weld then remove the Cu chill bar and flush weld if needed. A piece of scrap CU pipe flaten works well.

Finish grind the surface to suit your likes.

T_Bone

Good Luck and N-JOY!!!!! !!!

On the other hand, the "tractor tires only hold 12PSI" statement is deceiving. There's a lot of force contained in a tractor tire, even at 12PSI, enough to hurt or kill someone, if the tire or rim lets go.

You are exactly right about the ability of a tire to kill with 12PSI. We should think of these things in terms of stored energy rather than in terms of pressure. It could have 1000 psi, but if there was only one cubic inch compressed to that pressure, it would do little or nothing to release that volume of air. However, 1 cubic foot at that pressure would propell a tank through a wall. It's about stored energy.
That's why high pressure tanks are hydrostatically tested. The tank is filled with water, and then held under pressure. The water doesn't compress, so it is incapable of storing more energy at a given temperature. Therefore, if there is a failure, nobody is killed. Never underestimate the forces or energy stored in a pressurised tire.

Rod