How do you foam-fill tires?

Hi Blair,

You can get foam fill inserts for R/C car tires at a hobby shop which may work for you for a variety of sizes. Best regards.

-Dave

If I had to go about doing it, I would experiment with 2 part polyurethane foam rubber. I would make sure I had 2 part rims. I would fixture the tires so that they were held from the outside diameter, rotate them in a vertical orientation after pouring the mixture into them, and cut out the donut hole with a serrated knife. I would also build spacers to keep the bead of the tire at a distance such that when mounted, they fit the rims properly.

I would not, under any circumstance, fill the tires, then mount them.

Mike

I missed the earlier part of this thread. As an FYI, there are products on the market (Synair's Tyrfil, etc.) made for those. Much of it is for large equipment wheels, but wheelchairs use the same stuff.

How one obtains this stuff is another matter. I believe it is a polyurethane compound, and you're right about not filling the tire then immediately using it. The compound must set and cure for at least 24-48 hours.

It used to be you could get something quite similar at the home improvement store. Many expanding polyurethane materials were outlawed several years ago because while they cured they emitted chlorine. Like Freons and related chlorethylene compounds, they kill the ozone layer. What they have now might work, though it might not last as long, only if you could get it into the tire...

-- Gordon Author: Constructing Robot Bases (Forthcoming) Robot Builder's Sourcebook, Robot Builder's Bonanza

Blueeyedp>

--The tire filling stuff I've found so far is *extremely* heavy. Has anyone found any light-weight 2-part stuff that remains flexible? Something with the consistency of seat cushion foam would be ideal.