[67C10Step]

I just sold a 6.5x16 tandem axle trailer last month that was my father in laws. He had redone the floor in it about 15-20 years ago in did the same treatment as Sick472 mentioned. This trailer had sat in the edge of the woods for at least the last 10 years and the leaves and pine needles were about 6" deep all over the bed. I just knew it would be rotted out when I pushed all that stuff off but surprisingly, it was in pretty good shape.

I use the same method on my wood fence around my pool. Keep all my used oil and mix it with diesel. Makes it a dark brown and after a few days the smell goes away but it will sure repel water like no other. I was paying over $200 every other year to treat it and this only cost me about $30 in diesel as I have plenty of used oil around as I change my own and have four vehicles to service.