My tractor's fuel tank had 4 nuts embedded in the bottom that held on a skid plate and you can likely guess what happened after running over a bit of brush, yep all four bolts pulled on the nuts with enough force to crack the tank in each instance. The tank was warranted but it was taking forever (6 weeks finally to get a new tank) so I removed the tank to try a repair. I cleaned up the areas with plenty of acetone to remove all the old diesel, then took a power brush to it with my 4" grinder roughing up the area and widening the cracks a bit. I then mixed up a batch of JBWELD epoxy and layered it on filling in the holes with the nuts. After modifying the tank brackets so they protected the tank from future damage, I reinstalled it. This was in 2010 and it is still on the tractor and not leaking. The new tank arrived about a week later and I still have it in my shop waiting for the leak to appear again. I am not going to take it off till the repair leaks and so far after over 3 years it is still good.