[masraum]

Clearly what Shaun needs to do is build a box that he can fill with the product of choice that will fit all of the wood from the fence, potentially one board at a time if needed. Then you fill that box with product, disassemble the fence one board at a time and soak each board in the product for 24 hours. Then reassemble the fence with the boards that have been soaked.

Wait, WAIT! No, something that sounds more like Shaun's speed would be (again, one board at a time)...

A large bag full of the product that can then be vacuumed until it vacuum impregnates each board. That will result in some serious "soaking" of each board. Maybe a test run of boards that can then be cut and look at the cross-section to determine the depth to which the product soaks. It would be like looking at the smoke rings on a good brisket.

They'll last forever!