So I took the bedliner off my '73 F100 shortbed today and found a nasty (not so) surprise- lots of rust. The tailgate side of the bed is OK, but up near the front panel out at the corners the rust has eaten through the bed floor in some small places. What are some suggestions for the best way to repair this (and eventually get ready to paint the whole truck)
1. Just source a donor bed? Seems extreme since the rest of the bed is fine.
2. I have not found a repop bed floor for the shortbed. I could buy the long bed version and cut it down. That gets most of the problem solved, but not the corners?
3. Try to cut a few big patches off a donor truck if I could find one?

I'll try and get some photos later

 

The bed is the workimg end of a truck so unless yer going for a cheery resto, the low buck option is to cut, fab, patch and weld. Head to the yard with a recip and get what ya need... that is assuming the x-members and bed sides are decent enough to fill, block, and prime.

Pics would help...kinda flying blind at the moment.

 

If its bad enough lmc has the parts. I'm getting floor panels for my truck from them for in my cab, you can check them for the bed floor. Not sure on price. But that said do you have time to do it or want a quick fix.... If there's no time than a new bed would work. Do you or know someone who can weld and save you money.... For me since my brother is a welder he said he's doing it free. I'm still going to do something for him but I think you get the point.

 

I bought a piece of 11 gage steel 5 feet wide by 10 feet long, cut length to fit bed floor, notched sides 6" deep for fender wells, bolted in place using carriage bolts through into galvanized inner bed sides in three places ahead of and behind each fender well hump.

Then I got two pieces of same 11 gage about half as long as inside of head wall at widest, cut to highth of flat portion of head wall plus 2", had a 2" lip formed with a brake, trimmed ends to fit inside head wall and them to butt in center, welded them to floor and each other and bolted to head wall with some more 5/16 carriage bolts just under lip where head wall kicks out.

 

The floor will fit out of up to 96 tub. Might be a good source for donor metal.

 

If a donor bed is around $300 like here, i would say get the donor. If its harder to find, then cut n paste.

 

Just cut out the center section on my newest short bed. I ran into the same thing you did on replacement patches. The problem with those are they are not indented where the mounts are. Our local metal shop quoted me 174.00 for a 49 1/4 x 83 3/16 sheet. Going that route. I did consider removing a floor for another truck but it would be junk after you get it out. If it was dented up the metal is stretched and prob fit like crap anyways.

 

Thanks for the replies and sorry I've haven't posted any useful pics yet. The getting a piece of 15g steel cut to match the floor is appealing. Is it corrugated at all (like our beds) or flat? Seems like flat would wobble and not be sturdy enough. Some pics of your all sheet metal bed would be cool.

At the moment, I'm planning on removing the bed and finding a donor cab. At the pick'n pull (LKQ) around here a bed is between $150-$200, so cheaper than any LMC replacement panels. I was going to look for a newer donor short bed (thanks for the tip that any up to '96 will work), and cut out the floor and paste it in. I've heard that post '79 beds had 6 instead of 8 bolt holes, though I haven't checked yet. That is not too big a deal, just drill where needed.

My current question- after unbolted the bed (which was a PITA given the last 4 bolt locations), what is the best way to handle the bed? Can I just set it down on pallets or will the sheet metal sides bend? Is putting it on saw horses a better idea? Also, when I cut out the floor, what do I need to do to make sure it doesn't warp or bend on me? I will also need to replace at least the first cross member.

 

i have the same problem with mine i just bought a donor bed that the floor is perfect now just to get it out

 

Just finished a complete repaint of mine. Bed has a few rust holes under the floor liner in the bed. Small holes but no rust around them. After grinding away all rust, I used Duraglas to squeeze through the holes, then sanded the upper surface to match the floor contour. Coated both the under and top sides of the floor with POR 15 to seal against any more rust. Painted over that with urethane primer/surfacer and then urethane topcoat. I know this is not as good as replacing the floor but since the bed is covered by the bed liner, I figure if I can seal the rust, then coat it to keep it at bay for a few years, it should be fine. I'm not doing a frame-up resto, so getting a few more years for a couple hundred bucks ain't bad. It's a 79, so value is not that high, even if it had been totally rebuilt. I'm sure I'd sink way more into it that it's worth to restore it, so I'm just trying to keep it looking and running good. It is, after all, just a work truck.