Old tire help

[Zeal]

Making a kayak stand and since there are tires laying around I'd figure to use them as padding and to keep the wind from blowing the yak off the stand.

I'm making those 4 legged saw horses with the tops in the shape of a V and then just putting the tire in to keep the kayak supported.

Only problem is that none of them have an inner tube or rims and so I need help finding a way to seal the inside of the tires so the black rubber marks don't get on it and to keep critters and water out. I really don't think a ton of duct tape would work here or wrapping plastic around them.

It should be noted that the kayak ends will slide through the 2 tires to keep it in place, a third stand will have just half a tire to pad the yak.

Thoughts?