Necessity is the mother of invention.

[olderdan]

Noting new in using a tire as a reservoir tank but the pump is ingenious, I remember my father paint spraying the front wings on his Ford Y type using a lorry inner tube, I had to keep it going with a foot pump, it is amazing how much an inner tube will expand when not confined in a tire. An early form of a LPHV system?.

[Frank S]

I've heard of lead dust to weight construction tires; and reduces volume of air needed to maintain tire mounted on rim? Water isn't as heavy but WAY easier to get, unless a mile from the pump.

Yes lead dust is a lot heavier it does have a few pitfalls though. # 1 it is way more expensive than water #2 farm equipment doesn't get used every day. there are times when a tractor may sit for months and not get used the dust would have a tendency to settle and pack down also unless the tire was pressurized with nitrogen or another dry gas the moisture in the air would cause a layer of oxidation allowing the dust to clump probably never be a problem for construction equipment that was used a lot but if you had to drive the tractor several miles before getting to the fields it might be a really unbalanced bumpy ride for a while.
We didn't have weeks and weeks of sub freezing temps so what my grandpa used for antifreeze was a concentration of beet juice and corn or peanut oil.
Most of our tires were tube type so the fluid was pressure fed into the tire when the tube was new and had no air in it almost ZERO air. the tire that I punctured was on the newer John Deere and it was tubeless so it had water and air, and until the puncture not a whole lot of air either but there was no way I was going to be able to lug a 20 or 30 gallon drum of water and a hand pump to pump it back up to 35 or 40 PSI with water it in the field

[Frank S]

When I was stationed in Germany in the mid 70's there was this one German local who didn't have an air compressor but would touch up the paint jobs on cars in his garage he would haul a couple of truck tires at a time to the local service station until he had enough of them to use as an air supply for his job if he ran out before he finished he would use the oxygen tank. seemed to me that it would have been cheaper to just buy an air compressor