Most of them don't know how to weld it. Personally, I use low-oak rod. Seriously, a lot of people are afraid of wood because they don't take the time to learn the characteristics of the wood needed for a particular job. In the case of a floor for a vehicle, I would use a marine grade plywood. Marine ply doesn't have any knotholes or voids like the stuff you get at the big box stores. It's a lot more expensive but, if a marine ply boat hull withstands being immersed in water for years, it stands to reason it's going to hold up a lot better than something that water can get into.
I was going to mention the same thing after reading Ned’s post. I had a sheet I cut up and used for irrigation divert boards for 20 years, never swole, etc. I think originally “back when” plywood was used, it absorbed water, kept metal wet and made rust. Well, it did in the truck I took the toe board out of.
The Jalopy Journal
