Any chemistry majors out there?

[upupandaway]

I am trying to fill my (small) wagon wheels with foam. 3 tires are fine. 1 is giving me trouble.
I have used 3 cans of foam (where 1.5 fills the other wheels) but the tire is still soft. The only hardened foam is some that oozed out the holes. Some "goo" comes out as I spray more in the tire. It appears it is not hardening in this particular wheel.
I don't see any "slime" coming out. Anyone know if slime or whatever stops it from hardening? When I added more foam, I squeezed the tire a few times to "breath" if lack of air is the problem. Still no dice.

 

[Auto Doc's]

This stuff needs oxygen to harden up. Maybe laying it out in the direct sunlight will help. Other than that, I think you got some bad cans of sealing foam.

 

[upupandaway]

This stuff needs oxygen to harden up. Maybe laying it out in the direct sunlight will help. Other than that, I think you got some bad cans of sealing foam.

But it hardened up in every other tire I used the same foam in- including the other 3 tires in this wagon. Also, I used 1/2 a can in another tire and the rest in this one. I also squeezed and released the tire a few times to "breath" so there is fresh air inside. That's why I ask.

 

[TonyPrin]

There are many foam inhibitors out there, chemicals that inhibit spray foam from forming or sticking to a surface. One likely culprit is silicone that may have been sprayed on the wheel in the past. If so, WD-40 can remove it. One way or another, it's probable the wheel should be thoroughly cleaned with solvent.

 

[slomo]

Throw a tube in her. Slimes and foam are your last options. Maybe your wheels are too small for tubes????

 

[upupandaway]

Throw a tube in her. Slimes and foam are your last options. Maybe your wheels are too small for tubes????

It is just that i keep trying replace tubes replace whole wheels, even new tire stem, and they keep going flat in 3 months. I posted this issue before. So that's why I am going foam. So far so good- just one wheel. Being the foam works for this wagon and other stuff I put foam in, my last resort is remove the tire, clean it out and try the foam again because unless there is something preventing the proper chemical reaction, I don't see why foam works in all other tires but not this one.

 

[slomo]

Got to clean the rim like a new one. All rust and nicks got to go. Run your naked hand all around the rim feeling for bad/sharp spots. Also feel inside the tire for loose cords which can be steel shards poking the tube. I have 2 wheel barrow tires with blown out cords. I've had to take a file and smooth out some rims before where the tube rides. Little primer and paint will keep her rust free for at least 30 minutes LOL. All in the prep work.