custom flatbed highjack aka hey farmersamm

[Scott Young]

Sam, you posted a question in the custom flatbed thread that I wanted to get more info on. I have built three flatbeds and have assisted on several others. we always used 3 and four inch channel with 10 ga diamond plate tops there were some that had 1/4 in plated areas on some and some not. most headache racks were 10 ga or better square/rectangle tube or std or heavy walled pipe. depending if drops and left overs were used. We used 10 ga on the wrap a rounds if we wrapped and 10 ga on all the tool boxes topside and hanging. We would use 12 and 14 ga from time to time to build shelves, dividers, trays, and what ever we needed inside a box.


most of the trucks these beds were installed on were 1 ton or better. The wraps really add the weight. also, the substructure under the plate can be over built. 10 ga material is not anything to sneeze at when welded to crossmembers. I see too often people over build the substructure. by the time they get welder and tools and bottles, they are crazy heavy.


Sam, what sizes have you seen or used?

to any others who have built beds, what have you used and why? where can you save weight at and where do you need to add bracing?

I am not building a bed but thought this might be a good reference thread.

[Scott Young]

[NVW]

Most decks I build are overbuilt. They should out last several trucks. I use 6" channel for the sills and wrap the perimeter with 6" as well, makes a good solid tie down. Floor is 10 gauge checker plate. There is a picture of one in my album.

[irish fixit]

Personally I've seen a lot of overbuilt beds. Sure does cut down on the payload. In most cases the only failures I've seen is from rust no matter how light or heavy the bed was made rust is the killer.

The only real problem I have with J&I beds is that the light weight square tube cross members rust out. I've seen some that where very old and that was the only problem they had.

The bed on my truck is a old J&I that I've modified with toolboxes and to hold my welder and bottles. I've also added some heavier cross members where I mounted my poles to take the load from them. I've had lots of weight on those poles with no problems.

My toolboxes are made from what was supposed to be 14ga but actually measures closer to 16ga (I sent the first batch back to the steel company saying they where 16ga and they sent some more that they swore were 14ga).

In most cases the worst beds are welder beds. I had one guy want me to stretch the frame on his new truck so he could mount his old bed on it. When I looked at the old bed I was speechless. He kept going on about how most of the deck was 1/2" plate and all the toolboxes where 1/4" plate (he was real proud of it). Not unheard of in a welding bed but this bed was 12' long with a SA200, boxes all over top and bottom, and poles on it. I didn't know how the tires where staying up. I refused to do a simple stretch of the frame without plating it front to back. He kept saying it would be alright because it was a Super Duty. Yeah a F350 Super Duty and about the time that Ford was putting the lightest frames ever under the trucks. That bed would of overloaded a F550.

I had to fix the frame on another truck. Not unusual in a farm truck but it didn't take me long to figure out why the frame was broke. When I looked closer at the bed I realized that they'd used 1/2" tread plate to deck it with. That on top of the heaviest front bumper I've ever seen made the truck overloaded before you put anything on it.

[HOBART]

thanks for the info, scott. i'll definetly reference back to it.

1/2" plate??? i'm all for using what you got lying around, but a man hass to draw the line somewhere.

[mrmikey]

Just today I started a 5 ton flat deck for our wooden bridge crew. Going to have an 8' x 14' deck, 3- 2 x 2' x 4' long aluminum toolboxes down one side, a Bobcat sideways on one side at the front, cutting gear on the other side front.
Headboard will be 1/8" checker over 2 x 2 x 1/8 tubing framework, electric actuator operated arrowboard, gutter lights, led strobes.
Deck is 1/8" checker, bunks will be 3"C, frame rails 4"C, perimeter will be 4 x 4 x 3/16angle with 8" channel for the rear with inset oval led lights.
I'll post some pics when I get going if anyone's interested....Mike

[mrmikey]

A few pics of the deck just started, a lot left to do yet. That triangular piece is a weight to hold the chk plate down while I tack it to the bunks...Mike

[stuk4x4]

great pics, thanks for posting. I look forward to seeing the rest of the build.
Stuk4x4

[mrmikey]

Got the headboard/arrowboard mount done and mounted yesterday.

[farmersamm]

My smaller gooseneck trailers, and truck beds, have from 3-4" lightweight channel crossmembers under the deck. The semi trailer has 6" junior I beams for crossmembers (around 11ga or lighter)

In place of a a wooden deck I've always used 11ga diamond plate. I've always found it to be sufficient. Some people feel that it bends too much under heavy wheel loads, but I haven't had that problem as my crossmember spacing is closer in high load areas.

To give you an idea.........When I re-skinned my 20' gooseneck with 11ga, it weighed around 1000lbs (maybe 400lbs more than good quality oak).

The 11ga is sufficient for most loads. This Case weighs around 16,000 with thte wheel weights.



I took pics of the floor because I always hear that 11ga is too light, and will bend under concentrated wheel loads. This shows evidence to the contrary.





If the crossmember spacing is reasonable, or high stress areas boxed, 11ga is very workable and affordable. Besides......why would you want to reduce the payload of the trailer, or truck, by adding excess weight in the structure?

[RancherBill]

MrMikey
Very nice. What's your estimate of the weight?

You should close your locker so your street clothes don't get dirty.

I looked at the tail lights. Aren't they backwards. Traffic signs slope down to the out side. As a driver I have been conditioned to see the world like this. I see lots of trucks with them like yours and they always look 'funny' to me. Here's a quick pic I found.

[Scott Young]

Sam, what is your crossmember spacing?

I built a trailer that has a 10ga deck that has 2 ft spacing through the span and 16 inch at the stress areas. The crossmembers are 6 inch on top of two i-beams (I don't remember the size). It has carried a John Deere skidder most of its life, but it has carried backhoes, track equipment, and been used to haul a variety of misc. stuff. It has shown scalloping but after being in service for over 5 years and used weekly it has held up well. This was an engineered trailer with the deck being the only change from the plans per the request of the client(he already owned the diamond plate). the engineered signed off reluctantly.

[robphillips00]

We put 10 gauge on a new trailer ck we built last year. It was probably over kill. We put the crossmembers on 16" centers.

[Timster2]

Originally Posted by RancherBill

MrMikey
Very nice. What's your estimate of the weight?

You should close your locker so your street clothes don't get dirty.

I looked at the tail lights. Aren't they backwards. Traffic signs slope down to the out side. As a driver I have been conditioned to see the world like this. I see lots of trucks with them like yours and they always look 'funny' to me. Here's a quick pic I found.

This sign would indicate an obstruction in the middle of the road and you should pass on either side. These signs are what traffic engineers call an “object marker,” warning of a bridge abutment or some other intrusion in the roadway. Its slanted lines always point down toward the lane you’re supposed to follow. That said I guess you could make an argument that the tail lights should be slanted in the opposite direction. Next time you pass a bridge I bet you will take notice

[mrmikey]

Very nice. What's your estimate of the weight?

Thanks, never really thought about it truth be known. We have a set of 10K digital scales, when I'm done I'll get the actual weight.

You should close your locker so your street clothes don't get dirty

LOL, that's my tool/junk locker out in the shop. I've been there long enough now that I have my 'own' corner so I've got everything right there.

I looked at the tail lights. Aren't they backwards.

Ehhhh....dunno if there's really a right or wrong way actually. I just like it that way, personal preference is all. Odd you mention that, I had the rear channell all cut out for the id and tail lights and had it tacked upside down, a Homer moment.

I built a trailer that has a 10ga deck that has 2 ft spacing through the span and 16 inch at the stress areas

The deck on this is 1/8" checker, 16" spacing other than the front bay which is wider to allow for a set of bottles. I'm cutting out now for them, the fiddly stuff is what takes time but done right it adds to the esthetics(sp).......Mike

[Old Doug]

On my trailer the frame is part of the deck the out sides are 1/4 deck plate and center is wood. It is very durable. I like wood decks if you can get oak from saw mill and keep it oiled it will out last frame if you live in the rust belt.My pickup flat bed is also wood Deck its close to 20 years old. Steel decks look better but wood has its advantages.

[mrmikey]

Got the bottle rack built as well as the guard around the Trailblaser. The reason the guard doesn't go to the outside edge of the deck is there's a set of three 2' x 2' x 4' aluminum boxes run from front to back on the right side.
All that's left is to weld up the mount for the welder and fab the drop sides and mount the vice (vise?) the clamp thingy :-) ......Mike

[mrmikey]

Got 'er all finished, my part at least. Now it's off to be blasted, painted and get the compartments installed. Body shop does that end of it, they'll reassemble it as well. I'll post some pics when she's all wired and totally finished.
The chassis itself has to be looked at. New International Terra Star (pos truck IMHO). Looking at the front of the truck it looks as if someone loaded the drivers side down with a few extra lbs of something. It's down over an 1" on the drivers side, looks like he77, especially for a new truck.....Mike

[mrmikey]

All blasted, painted, wired and installed

[mrmikey]

Last three pics. The aluminum cabinets were bought, cheaper than making them at $750 a piece. I think the latches alone must be worth at least $50 each, if not more.
I couldn't get the finished weight, somebody liked our scales better than we did or else they grew legs :-(......Mike

[Scott Young]

Great looking bed! I love the tool boxes. I saw some the other day that I priced the material for to copy. the material alone was 25% more than the finished box. It is a shame you can't by raw material inexpensively anymore.