repair split dryrot in rear tire?

Ok so my 13.6x28 6 hoop wheels need a repair around the valve stem - rotted when filled 20 yrs ago. PO drained the tires but they're pretty crazed, got a 1&1/2" gash in the sidewall where the tube sticks out.

2 questions:

1. Can that be patched from the inside with a hot-patch type repair, maybe gluing a section of passenger car tire to the inner carcass?

2. trying to pop the bead with the bottle jack between the chassis and the tire (ok, cheating, using a port a power) the 2"x3" pad of the ram is skidding along the sidewall of the tire instead of pushing the bead off. Do I use a long 2x6 to keep pressure on the whole edge of the tire or put the valve core back in so some air stays in there to keep the tire from collapsing?

I have repaired a good many with bigger hole then that. You need what is called a boot patch. What that is, is a heavy duty patch that comes in 4X4 6X6 etc etc. I have even seen one as big as a 12X12 inch patch. You clean up the tire on the inside then glue the tire and let ti dry a bit then put that big patch on. I take the tube then and put it in the tire and air it up so it holds that patch down good and tight and let it sit an hour or so. Done that a good many times. As for break one down get a tire hammer and learn to use it jack etc are good ways to get hurt.

I use one of these gadgets to get them off when I need to.
Problem I have been having lately is that the tire shop only
charges me $20 to drain the chloride and break a rear off
the rim for me. $5 for a front tire. Maybe I'm getting old,
but I've been letting them do a lot more of them lately....

Little Buddy Bead Breaker

hmm, maybe I should look and see what my local tire shop would charge.

I have that things big brother. I have what is called a truck tire bead breaker. Uses an air cylinder to clamp the 3 piece foot to the rim then a bigger cylinder that pushes the center foot down. Works very well and the nice thing is I found it in a junk pile that I was told I could have any or all of what I wanted and have had it for 25 or so years now and the cost was 00000

Depending on the nature of the break and it's direction it may
work with a large boot and patch. What will ruin it depends on
how much flex is in that broken area from being loaded to
heavy to driving over logs and other objects. As far as
knocking the tire off. You can do it with a porta power or bottle
jack , I've done more than I can count that way. Keep the core
out and stay as close to the rim bead as possible when
jacking. Won't hurt to put something like wd-40 between rim
and bead. Also stay in same area when jacking within a foot or
two of both sides of your first jacking spot. Tire slide hammer
is also a great tool for bead breaking the front side and will
work on back if you have the room. Thing to remember:
always break the back or in side bead first, when using bottle
jack, porta power, or handy man jack always put tractor in gear
or set the breaks, finally always remember that a jack type
device is a potential bullet or man killer stay the hell out of its
path.

WD40 does not work very well on tires but dish soap does. WD the W stands for water and the D stands for displacement and the 40 well it took them 40 tries to get something that worked

You can drive a vehicle tire onto the sidewall when laying flat. If you have a front end loader, I have used mine to do the same thing, even if its the tire off the tractor, safely block up the back end, roll wheel to the front, use down pressure of the loader bucket to break the bead. I use a piece of lumber to catch more of the tire and protect it from the steel bucket. With this sidewall and tire condition, you may have to use care so as not to cause further damage. Once the bead is broke, you can use tire spoons to work it up and over the rim. Use the spoons in pairs and only grab a few inches at a time, take too much and you will hear the strands or whats inside the tire bead tear. A few inches at a time is all you need, and just work your way around the rim, once one side is clear, the other is easy. Repair or replace tire as needed.

Rim, if its otherwise solid, you can sand blast, wire wheel it clean, however you do it, then make a repair to the rim, if you can weld or someone can do it for you. I had to do one some years back, was a new rim when I had a tire replaced, had a small leak at the valve, which the tire guy said would stop, it did, I should have dealt with it sooner. I just plug welded that hole shut, drilled a new hole, and should have flattened a spot where I did that, but it worked out just fine, been since '08. Just have to make sure the welds are good, I built up thickness on the exterior side, then ground the inside smooth, primed the inside of the rim with zinc rich galv spray, as its what I had on hand.

I mounted the tire, installed a new tube from the tire supply house, not sure if china mfr or what, been good all these years. Partially inflate the tube, then let the air back out, then fill to operating pressure, which I believe was 14 P.S.I.

Periodically, I have changed valve cores on these CA CL loaded tires if I pull the valve stem cap and it leaks.

Never, for any reason weld a tire rim with a tire mounted, seated or not, it MUST be off the rim. See below link if you are interested as to why.
Bridgestone Wheels of Fire Training Video

One fellow had an old McC-Deering with a patch that was bolted to the inside of the sidewall with carriage bolts. he brought it to the tractor pulls year after year.

gears by doing that with the bottle jack, you risk breaking the sidewall of the tire even more. I've seen lots of them broken down that way. Do yourself a favor, take it to a good farm tire shop and have them fix it. It may need a section installed in the tire.

Holy Cow, I learned a lot about tires from that video. I didn't know about the chemical reaction that happens when a tire over heats for any reason. I take a completely different look at dealing with tire/rim heat situations.