It looks like we are getting down to the final bits of fabrication on the frame for Dan's RPU.............this weekend we worked on boxing the frame. The reason we have to box it is because Dan elected to have 3/16 steel bent up into a C channel shape for the siderails, rather than use box tubing. He wanted the front part of the frame tapered, and also wanted to "step box" the frame. For those of you not familiar with the term, step boxing is where the inside boxing plate is not flush with the outside of the frame, but is inset a little bit. By step boxing it, he can run lines and wires and they will be hidden inside the frame somewhat.
He bought some 4 inch wide x 3/16 steel plate, 16 feet long, and we sliced the lengths we needed from that. But before we could put the boxing plates in place we had to create something to keep them at exactly 5/8 of an inch from the outside edge. What we came up with was a bunch of 3/4 inch angle iron pieces about 1 inch long, that we welded into the frame to act as "stops" that the plates will rest up against. This way we can clamp the plates down tight against these stops and then fully weld them in place.
It took a lot more time than we thought, because first of all we had to drag the frame outside so we could sandblast the entire inside of it so it would be clean enough to weld to. Sandblasting is one of my very favorite jobs.(NOT) Even with a paper suit, goggles, and a respirator, sand still found it's way past all that. That is one more job I found that I wouldn't want to do for a living.
Once it was blasted we got the stops welded in place and cut the boxing plates to fit. There are three boxing plates per side, one under the body and two in the engine room section. There will be about 36 feet of weld to do, and Dan is going to have to do it a little at a time so it doesn't warp on him. He figures it will take most of at least next Saturday to get the welding all done. But boxing it did clean up the insides of the frame nicely, and now it looks like a more finished frame with them sitting in there.
Next step after the welding is done is to figure out how we are going to coat the frame. We don't think painting it will work real well because of all the nooks and crannys there are.........it would be tough to get paint evenly into all of those places. Powder coating is an option, but we have to figure out what we can do to smooth the frame out. You can't use body filler with the high heat of the powder coating process, so we are looking into all metal or lab metal as a means to do that. We just have some more research to do before we decide.
Here are some pictures.
Don
Here are the stops welded into place
And after the boxing plates were slid into place.