On Thu, 28 Apr 2016 09:50:12 -0400, Ralph Mowery
wrote:

In article ,
says...

I wonder what would happen if someone took a small tire, such as the
ones on wheelbarrows or push carts (dollys) and just filled them with
Spray Foam (such as "Great Stuff" brand).

It would seem to me, that you could just remove the valve stem core,
insert the nozzle from the spray can into the valve stem, and fill the
tire. I guess the only concern would be to make sure the whole tire was
filled, and not leaving parts of it empty. The foam would expand and
make a solid tire.

Has anyone ever tried this?

The trick would be to get enough in the tire to fill it, but not too
much. If too much is put in, it would probably push the tire off the
rim or bust it.
I don't think it is physically possible for the foam to exert enough
force to demount the tire.

It'll work for a while. Eventually the foam may break down and turn
into powder, but it will take some time and some load.. It will ooze
out the valve stem long before the tire comes off!!!!