I finishing up my 6x9 utility tralier that I started last summer. I have a running total of about 40 bucks in it right now. The floor isn't treated and I was wondering what I could do on the cheap that would make the wood last longer. I was thinking about just painting it black but my dad said to use criso or old motor oil to treat the wood. If I do this then will that not make the floor nasty...thus making all the stuff I haul nasty?