I made one out of aluminum and it just wouldn't take the vibration and abuse... my son the engineer told me that you can't get an aluminum weld to ever be as strong as the base metal... . and that answered a lot of questions... . I've thought about building one with bolted connections instead of welding it... .
Mine are all made from . 120 tubing on the edges (2x3) with a pieces of 1/8 thick angle welded from side to side... we used to use 2x6 TG Fir as a bed with a generous coating of linseed oil as a coating... its a very protective coating...
We beveled the corners of the frame at the cab and at the end of the bed to allow for ease of entry into the back door and for easy access to the rear when we're connected to a 5er... .
On the latest one... we used a synthetic wood, like trek but a different brand to more suit the color and texture we wanted... .
We hung a 50 gal fuel tank on the passenger side and adapted the mechanism to raise and lower the spare tire... we've got (4) 35 watt floods for back up lights, the sealed 4" lenses for the other lights... we don't use LED's... our winters will allow for a cake of ice and snow on the back and you can't see the LED's there's not enough heat to keep them clean... .
We use 4-6 points to drop to the frame on each side. . that way the light angle and rectangle tubing can take the load... the bed is about 2" higher than the stock bed...
All the exposed metal was cleaned and coated with a roll on bed liner material. . I wanted to have it sprayed before installation but non of the guys in town would do it for less than $250, the same price I pay to have a bed sprayed... . so we passed.....
We've had something like 6,500 lbs on the back with no problems... . of course we've had to have the air bags at max to level the bed... . We'd often put 4-6K lbs on the back and run off to deliver parts... they are not babied...
We have a D&W goose neck hitch and the companion when we pull a 5er... .
Our 04 with a wood deck(resealed once) now has 300K miles and the 05 with the synthetic wood has 120K miles...
I sometimes take 2-3 months to make one in my spare time... . and draw it in AutoCad so all the parts fit the first time... . its been a great experience... .
I'm packing for a 10 day elk hunting trip otherwise I'd take some photos and post them...
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