Attention: TDR Forum Junkies 
Here goes...
Shortly after buying my '93 D350, I found the rust. Installing new starter contacts, I saw what appeared to be a minute bubble on the underside of the driver's floorpan.
I'd consider myself a decent welder, how hard could a simple floorpan be??
Shortly thereafter, removed the carpet - and found this:
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Rest of the cab looked like this:
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Ordered a replacement floor pan from Sherman, via Amazon... Pan was $56, shipping to Kodiak (a remote Alaskan island) was $75!
Began cutting... And cutting...
After degreasing, the cab mounts appeared to be in excellent condition. I'm fairly confident that the previous owner regularly oiled the underbody of this truck.
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I was extremely lucky; as the rust was entirely isolated to the driver's floorpan. None of it whatsoever had made it's was to the cab mount or frame/rockers. Interesting really, I figure the combination of the stock water trap jute insulation / water intrusion is what accelerated rust on that side. The spot welds were where the worst rust damage seemed to be occurring.
I had to modify the floor pan quite a bit. The major flat areas of the panel fit well; where I had trouble was where the replacement pan met the transmission hump, and by the firewall. I had to fabricate/form a "scab" piece that entirely covered the area beneath the pedals, as rust had made it's mark there as well.
Primed with "Weld Thru-It" zinc rich weldable primer.
#ad
Cab mount / Frame Primed
#ad
Waiting for primer to dry, I focused on the seat. As the legs had developed some heavy scale where they mated with the saturated carpeting.
#ad
Needlegunned / Degreased
#ad
Primered:
#ad
I'll skip the boring and ugly welding pictures... (Butt welded fully)
Being the first floorpan repair I've ever attempted - there were a few rookie mistakes that I made, which added significant time and frustration to the fit up process. Namely, attempting to measure / cut the panel without having it in place in the truck. Also, ignoring nearly all of the advice that I'd come across - I was premature with a few cuts, that ended up leaving significant gaps around the replacement panel. I'd venture that these mistakes easily added a day to the project.
Here is is fitted up:
#ad
Also, the entire cab floor was sanded with 36 Grit on a random air orbital (for paint prep). All areas of slight rust were sanded, those that were heavier were coated with Ospho (converts rust to iron phosphate).
Decided to use a two part epoxy paint and primer system, as I'm intimately familiar with it after years of painting the commercial fishing vessel that I captain.
Holds up extremely well; and leaves a high gloss finish.
One coat of primer (impregnated with aluminum); 3M Urethane seam sealer on both cab and underside on all welds.
#ad
#ad
Two finish coats: (Bad lighting too!)
#ad
#ad
Hope that she'll be good to go for another few years at least!
Seat goes in tomorrow after the paint has had time to cure.
Contemplating a vinyl carpet and sound deadening material. I'm already diesel deaf from my time spent on the water...
Shortly after buying my '93 D350, I found the rust. Installing new starter contacts, I saw what appeared to be a minute bubble on the underside of the driver's floorpan.
I'd consider myself a decent welder, how hard could a simple floorpan be??
Shortly thereafter, removed the carpet - and found this:
#adRest of the cab looked like this:
#adOrdered a replacement floor pan from Sherman, via Amazon... Pan was $56, shipping to Kodiak (a remote Alaskan island) was $75!
Began cutting... And cutting...
After degreasing, the cab mounts appeared to be in excellent condition. I'm fairly confident that the previous owner regularly oiled the underbody of this truck.
#ad#adI was extremely lucky; as the rust was entirely isolated to the driver's floorpan. None of it whatsoever had made it's was to the cab mount or frame/rockers. Interesting really, I figure the combination of the stock water trap jute insulation / water intrusion is what accelerated rust on that side. The spot welds were where the worst rust damage seemed to be occurring.
I had to modify the floor pan quite a bit. The major flat areas of the panel fit well; where I had trouble was where the replacement pan met the transmission hump, and by the firewall. I had to fabricate/form a "scab" piece that entirely covered the area beneath the pedals, as rust had made it's mark there as well.
Primed with "Weld Thru-It" zinc rich weldable primer.
#adCab mount / Frame Primed
#adWaiting for primer to dry, I focused on the seat. As the legs had developed some heavy scale where they mated with the saturated carpeting.
#adNeedlegunned / Degreased
#adPrimered:
#adI'll skip the boring and ugly welding pictures... (Butt welded fully)
Being the first floorpan repair I've ever attempted - there were a few rookie mistakes that I made, which added significant time and frustration to the fit up process. Namely, attempting to measure / cut the panel without having it in place in the truck. Also, ignoring nearly all of the advice that I'd come across - I was premature with a few cuts, that ended up leaving significant gaps around the replacement panel. I'd venture that these mistakes easily added a day to the project.
Here is is fitted up:
#adAlso, the entire cab floor was sanded with 36 Grit on a random air orbital (for paint prep). All areas of slight rust were sanded, those that were heavier were coated with Ospho (converts rust to iron phosphate).
Decided to use a two part epoxy paint and primer system, as I'm intimately familiar with it after years of painting the commercial fishing vessel that I captain.
Holds up extremely well; and leaves a high gloss finish.
One coat of primer (impregnated with aluminum); 3M Urethane seam sealer on both cab and underside on all welds.
#ad#adTwo finish coats: (Bad lighting too!)
#ad#adHope that she'll be good to go for another few years at least!
Seat goes in tomorrow after the paint has had time to cure.
Contemplating a vinyl carpet and sound deadening material. I'm already diesel deaf from my time spent on the water...
