Motorcycle gas tank repair - how about a bladder?

I'm thinking of buying a project bike, but it has a rusty tank.
Poking around online, it seems as though there are many solutions, but none of them good.

What about a rubber bladder-type insert? Does anyone make these? Seems like this would be a definite cure.

Any idea where I can find this? Any other solutions?

Thanks!

every tank is shaped differently .so a bladder will not work on most bikes..however if you clean the tank the best you can..
.( shaking old nuts, bolts and paint thinner around in it works well)
then coat the inside with a cream sealer it wil be rust and leak free many years to come..

even when buying or building a new tank i always use a sealer

if it has a rusty tank it will cost more to repair than buying a new one or newly painted one from ebay!...I wouldn't go with the bladder idea...even if they did make one

Yamaha makes a very good 2 part rust remover. I have had good results with it. It costs less than $20.00 for the kit, so why not give it a try if you like the stock tank. If there is paint on the tank the Yamaha rust remover won't hurt it.

Why repair? Hit up the scrap yards, swap meets, and Ebay, and find a replacment.

I can't find confirmation of this but I think petrol is a rubber solvent, which could be a problem.

Kreem or Caswell's Epoxy systems are considered the best inexpensive solutions.

That wouldn't work, you couldn't get the fuel out through the fuel petcock