This is a tip for shop and home use. My wife has a hose cart she uses for watering yard plants. It has two 2” x 20” tires with spoke wheels. Both pneumatic tubes developed leaks which didn’t seal with green slime so I needed to find another solution.
I could have gotten two new tubes for $20±. I could have gotten a solid foam insert for $60±. But I decided to try using Spiralite 115-00 suction hose which could buy at our farm and ranch store for $1.25/ft. I had to buy a minimum of 10’ for $12.50. I cut the pieces to length and worked the tire back onto the rims and the tires were stiff enough to work just fine for the light load they carried. My wife is happy with it.
I had a backup plan in case the weren’t stiff enough. I could go back to the store and buy a stiffer type of Spiralite hose or I could fill the hose with an expanding urethane foam such as GreatStuff for about $4.00.