Figured someone here might find this interesting.  Here’s a galvanized steel flatbed I built for my truck the summer before last.

The truck used to have an F350 dually box on it, but I had a recap drive tire come apart and destroy the box floor, box side, plastic dually hip, rear bumper, tailgate, mudflap bracket, etc.  I got a decent check from the insurance company and used it to purchase a complete rear frame cut from an International 4300 with air suspension, a used wheel lift from a rollback, and the materials required to build this flatbed.

Lots of head scratching went into this build to eliminate the possibility of warpage.  You can see how the tiedown rails, front bulkhead, wheel tubs, and toolboxes are separate elements that bolted into the skirts after all the parts had been hot-dip galvanized.  I knew if I welded everything into an assembly prior to giving it a bath in molten zinc, the stresses would concentrate in certain areas and cause the flat panels to bulge and ripple.  Allowing the 12ga skirts to expand and contract unencumbered seems to have allowed them to return to their original dimensions when they cooled.

You can see in a few photos the holes I left in certain parts of the the body to allow air to escape and molten zinc to enter the forms, as well as the holes I punched for the extruded U-nuts that hold the Apitong decking.  These were punched with my old Strippit Sonic 15 thin turret punch, prior to forming the crossmembers on a press brake.  Again, lots of head scratching went into the design.

I also pulled the engine out of the truck and replaced the flywheel housing with another that would accommodate an OEM Wabco gear-driven air compressor, then built an onboard air system with a couple of Freightliner tanks and an AD-IS dryer.

This F650 was a regular cab 24ft box truck in a previous life; I rescued it from a Copart lot in 2014 and turned it into what it is today, but that’s a story for another day and probably a different subforum.

I’ll throw a few photos of the original build in here:

Nice work.....end result came out great!

Wow! Awesome build.

I guess I never realized how BIG 650's were until recently. A friend was in the process of moving to Wisconsin from Idaho and their U-Haul rental was a 650. They were concerned it might not have the power to pull a trailer behind it AND have a fully loaded truck with their household in it. Apparently, it had ZERO issues.

They’re not fast, but they’re meant to be driven at full GVWR with the pedal to the floor and never burn themselves down.  That’s why you’ll see a 220hp Cummins in a medium duty truck when the same engine is 300+ hp in a 1-ton.

Attached File

Nice build OP!


Yeah, look at the specs for a 6.7 Cummins pickup truck engine and a 6.7 Cummins industrial engine. Wildly different specs, same block, head, crank, pistons, & rods. Different cam and different PCM/ECM tune.

IIRC the ag engine is rated at more than double the torque...

Yeah.

If I were to build another one, I might put an ISL9 or 8.3 in it and back it with a 13-speed... but at that point, I’d probably just find a cool old cabover or an LTL9000.

Oh yeah... this involved some metal fab, too.  I didn’t put a lot of time into this, because I was supposed to be overhauling a rusty-ass service body for a friend’s Dodge 5500, and it was soul crushing work so I distracted myself with this side quest while he nagged me for progress updates.  

Hauls the load a little better than a limp-wristed 1-ton - no need for overload springs or bags, aftermarket sway bars, or white knuckling through curves.

Got rid of the stupid electric jacks, built fork pockets into the subframe like a boss.  








Sold the antique Allis Chalmers and got a diesel Hyster H90XMS now.  


Off to galvanizing.


Back from galvanizing.




Enclosed, lockable storage.  (Not weathertight.)


Ladder-on-ladder storage.




“It’s a car you can poop in!” -RCR


Albert Lea, MN last night on my way home from a tattoo appointment in Cedar Rapids, IA.  I got 8 MPG at 75 MPH.  Might do 10 MPG if I’d slow down, but I’ve got places to be.

Nice work!

I'll subscribe to any threads you make about this truck, just lmk where they are. Lol

Cool stuff!

Very cool!

What is the reason for hatches in the middle of the bed? Any particular reason for deck vs tread plate?

That in 4x4 is pretty close to my dream rig. Great work OP.


METOO

Shit, that's a fuckin beast! I like the regular truck body look the best.

Front hatch: batteries.  Rear hatch: gooseneck ball.

I put a diamond plate deck on the first flatbed I built (Isuzu pictured in OP) and it warped badly when it was galvanized.  Plus, you can’t screw dunnage to steel and it’s loud as hell when you throw a chain across it.  And as much as I hate working with wood, I acknowledge that exotic hardwoods are cool.  

The dually box?  It was cool for a hot minute, but it’s beyond worthless.  Pretty much impossible to tow a gooseneck with a standard-height neck, and it attracts way too much attention.  Any time I’d stop anywhere, a group of slackjawed morons would surround me and ask:

“How many emm-pee-gee does that get?!”
“Boy I’d hate to fill those tanks.”
“What do ya use that thing fer?”

It looks a little more like a commercial truck now, so it’s invisible to the average suburb dweller.

Nice job!  Like others, I'd be interested in other builds.  Do you have more pics of the truck build?

I was interested in an Excusion/650 build but I need a truck and trailer.  I need a bit longer cab than the 4 door.

Funny you should mention that; I started collecting Super Duty cabs and parts to build a 6-door 4x4 F-650, but I got really busy at the family business and it got backburnered.  I have a rust-free running, driving 2WD crew cab F250 with a timing chain rattle, a couple of good cabs to use as sheet metal donors, a nice long frame from a Hino box truck, and another F650 clamshell hood and firewall.  I actually bought an MTV (M1088A1) about five years ago with the intention of using its engine/trans and front and rear-rear axles in the aforementioned 6-door build, but I drove it home from Fort Hood and kinda fell in love with the stupid thing, and can’t bring myself to cannibalize it.

Regarding the request for more photos:  I do have a ton of photos of the whole build process, but a lot of it is pure mechanical drudgery, and might be kinda spammy to post here in the metalworking subforum.  To avoid re-uploding all the photos, I made the gallery public on my Facebook profile, here: https://www.facebook.com/colinrdoyle/albums/10152127518163924/

Hate that platform, I’m mostly on Instagram (@colinrdoyle) but there are a lot of old photos still hosted on FB.

This thread is awesome.....

OP, fucking A!  You got some skills man.  Great pictures and overall that just looks awesome!

Thanks.  It’s been a long uphill battle, always had the urge to create stuff and I’m just finally starting to be able to breathe life into some of my visions after 20+ years of trial-and-error.  Didn’t have a mentor in my life for this type of thing, so I ended up making every mistake in the book while teaching myself.  Never stay down when life kicks you in the teeth.  

I’m starting to dabble with metalshaping and machining now.  Perpetually a novice.

Very nice work

If I understand this right, he isn't welding galvanized. He is just sending everything off to be dipped after he is done building.

Amazing thread OP. I will have to keep an eye out for this truck and come ask you how many MPG's it gets lol.

I always wear two condoms when I weld!  

I haven’t needed to weld anything post-galvanizing, but I do have a fume extractor and a respirator if the need arises.

That's fantastic!  

I agree, great design.  I like the modularity of it.

Thanks.

I’m currently stripping a 1997 Tacoma (pictured above) and preparing to galvanize its frame.  That’s a rust-free Georgia truck that got dragged to Salt Lake City by a transplant and swallowed a valve before its first winter.  We currently plow snow with a 1st-gen Tacoma, but its frame is about to break in half.  Hopefully zinc plating will be a permanent solution to these trucks’ Achilles heel.

I woke up this morning considering putting a flat bed on my '04 Tacoma thinking it may make it handier for farm use.  I also thought if done properly it might hold the frame together a bit longer  I'm glad I found this thread.

One distraction after another, but it’s getting there.

How much does it cost to get a frame or bed galvanized?

If I recall correctly, the bill for all the flatbed parts was about $1700.  Definitely couldn’t pay someone to powdercoat all the parts for that price, and I ended up with better coverage and a far more durable surface treatment.

They charge by weight.  The company rep explained that they bill based on the increase in weight as zinc is deposited on the surfaces of the part, so if you bring them a big heavy steel tube designed to support a billboard, it won’t necessarily cost much more than a bunch of lightweight sheet metal flatbed parts.

At my local galvanizing outfit, there’s a minimum flat fee for small parts under a certain weight.  I have a friend who was going to have a lightweight Land Rover firewall galvanized, so I threw in a set of pickup camper tie-down brackets and this EZGO dump bed and basket/bumper, and we still didn’t reach the point where they began charging by weight.  We split the fee and both made out like bandits.


Here’s my ghetto-ass DIY UTV