If you have rubber tires that continuously become flat from either rolling over nails or because the inner tube has various small leaks, consider filling them with foam. But make sure you don't mind having more rigid tires on your vehicle or devic. Rigidity can lead to various disadvantages for a rubber tire.
Ideal Vehicles or Devices
A foam-filled tire replaces the tire's air with an expanding rigid foam made from urethane. Such tires will never go flat, and are useful for tires punctured repeatedly. But they have several disadvantages. Foam tires are rigid and more difficult to maneuver when moving. Do not use them if you need your vehicle to handle well. Additionally, foam-filled tires cause additional wear on the tread because the air allows for flexibility, putting less strain on the rubber. The strain is especially apparent in heavier vehicles like tractors. Smaller tires are ideal for filling with foam; consider filling your lawnmower's wheels, for instance.
Before filling your tires, wear safety glasses. If you are filling a smaller tire, like on a lawnmower, you'll need at least two cans of "minimal expanding foam." Lift the vehicle off the ground so the wheels are not resting on any surface. Drill a hole that's about the same size as the can nozzle.
It is also important to remove the wheel's valve stem insert with pliers to allow air to escape from the tire as the foam takes its place. The valve stem insert is the metal device inside the valve stem. Make sure the hole you drill is just above the valve stem. Watch the valve stem; once the foam begins to ooze out at the "bottom" of the wheel, cap the valve stem, and continue to insert the foam until it oozes out of the top "drilled" hole.
Review your wheel's inflation pressure requirements. Purchase a foam of a high enough density to replicate the wheel's requisite inflation pressure. The higher the foam density, the higher inflation pressure it can adequately replace. Review the manufacturing specifications for your wheel and consult with your local hardware store to obtain the correct foam density.