I finally got some more time to work on my gear box trailer. The floor frame is built out of 1-1/2 x 2-1/2 construction lumber (ripped 2x6s in half and trimmed.) They are held together with pocket screws.
It may seem like there are extra joists in the build. I wanted to match the three bold holes in the cross members. I also wanted to make sure the outer side joists were bolted to the trailer frame. They carry a lot of the strength when fastened to the sides of the box.
Who knows. Maybe I could have done without the two inner joists. If the bolt holes were not already there I would have use four evenly spaced ones.
The wooden frame is also a bit overbuilt because the box extends beyond the rear of the trailer. If I end up liking the idea and build a custom trailer I can probably skip the wooden frame.
My son is learning how to use a brad gun to tack down the floor. I used Gorilla Glue and brads to hold the floor in place. Figure the bolts holding to the trailer will work pretty good, too!
We glued and brad'd the front panel into place using GG. After doing more research, I am not sure GG is the right way to go. I was looking mainly for waterproof joints. It sure is a mess. (OBTW, heed the warning about wearing gloves!)
I should probably use screws to tighten up the joints while the glue dries. I am also planning on using 1x2s (or something like that) on the inside of all the plywood joints.
The corner brackets sure helped keep things aligned properly. They have been sitting in my shop for several years and haven't gotten used until now.
Tomorrow we will cut the doors on the side and back panels, afix them to the frame and figure out how to make weatherproof doors!
It's amazing how often a plan changes once you start actually building it!
Feedback (including constructive criticism) is certainly appreciated.