Take a look at this thread. 1947 Farmall Cub project Along with cleaning up the rims cjet69 also mentions patching an area around the valve stem similar to what you are showing. Think that's on the first page.
Thanks for that idea. I can see that welding solution for a project on a tractor where the parts are not available but for this one, the parts are very available.
But my concern is how long can be get away without doing anything.
I got to thinking about that corroded rim on our JD 301A.
I looked up a Youtube video of a big tire like this one in a safety cage exploding at 150psi. Wow. The tire was not harmed at all. The steel rim burst. It destroyed the cage and would have surely killed any human who was near it without heavy duty safety protection.
I sent the video to the boss of the work crew that uses that tractor.
I got a call from the boss of the Parks and Rec after I sent him the video of an exploding rim and what damage it can do. He was concerned for the safety of his crew. So am I.
1. I know that the pressure on the interior of that tire is exactly the same no matter where it is sitting or rolling on the road. But, is there more stress on the part of the rim that is down than the part that is up? My guess is NO. But I need some confirmation of my feeling.
2. I can see why a tire at 150+ pounds is deadly. But at 12 pounds of pressure, what is the likelihood that corroded spot on that rim letting go and hurting someone?
Actually, if the tire is filled with a liquid, such as CaCl, the tire is MUCH safer to work with, as the danger is in how much the contents of the assembly can expand. At say, 150 psi, air compresses a lot, so when it is uncontrollably released, it expands to it's original volume quickly. Liquids on the other hand, don't compress very much, so when they are released uncontrollably, it just squirts out a little bit and that's it.
Now, there is still some air in the tire, so there is still some danger. And for working on it, I would put that valve at the bottom, as if it does happen to fail, it will be liquid coming out, which can't go through the failure point as quickly as a gas can.
Edit: fixed "still some air in the TIRE".
And to clarify, having the weak spot at the bottom if/when it fails, a bunch of fluid will come squirting out at 150 psi (so you'd want a blanket or something to control where it goes) until the air inside the tire expands to it's uncompressed volume. It's safer because the liquid can't go through the opening as quickly as air can, so it happens over a much longer period of time.