Pardon the newbie questions.

I haven't had the opportunity to visit a HDT conversion shop yet. I intend to soon. I read on another thread the standard floor tubing is 2"x3" 11 ga tubular steel, 16" o.c. and for walls 1"x1-1/2" 16awg tubular steel, 16" o.c. where possible. Most of the tubing I see in photographs looks much much larger. Are most converters in fact using the above size tubing or something larger.

Also, are steel rivits and steel sheeting for exterior covering just a no-no?

I am operating with the following logic. If wrong please feel free to correct me.

At best I drive 5000 miles a year. Let's say I win a lottery them it's 6000.

Therefore, I don't see myself driving the 10's of 1000's of miles necessary to amass any substancial savings in fuel cost one would eventually accrew by building a conversion a few pounds lighter over a few pounds heavier. Ofcourse fractions of an inch in tubing size can amount to 1000's of pounds on the end conversion weight and over all vehicle performance. Performance especially noted going up and coming down steep highways.

However, with only the weight of a conversion or a factory 5ver to pull around seems to me this is still well under what the truck was designed to safely move and stop. And so when speaking fuel cost/milage, it is not going to be that greatly affected by a little more or less weight on the truck itself.

Now then, being a HDT newbie, if my arguement is full of it ---- I'd certainly appreciate an education. Thanks to all. I appreciate the opportunity to be among you.

I think the main reason steel plate and rivets are not used is the corrosion issue. Plus, the industrial adhesive tape used to attach the aluminum sheeting is actually stronger than rivets, and the lighter aluminum means the tape doesn't have to hold as much weight as with steel.

Yeah, just wait until the tape lets go and your aluminum skins start popping off. Then you can listen to the manufacturers give you excuses as to why it happened. The truck conversion manufacturers are using you as an expensive experiment. Good luck. Been there, done it and have been paying the price for the last 3 years. As an example, take a look at the way your sheet aluminum roof buckles when it heats up. Is the aluminum skin on the walls different than the roof? When it gets hot, it needs to move. Since it can't move up and down, it pushes it's way out and pops itself off the super magnificent tape. Then it cools and goes back in place, but the damage is already done and after several times, the tackiness is gone from the tape. The fact that the body also racks and rolls when you're raising it on the jacks and simply driving down the road doesn't help either. Listen to all those creaking and cracking noises. Where do you think all those noises are coming from? I'd love to strip all the aluminum skin from one of these rigs and take a look at the welds on the framing. If you're able to look at a rig under construction, look at the welds. Most don't have any penetration and are just held together by the filler material. In other words, a lot of the frame is simply tacked together, especially the basement storage tubing.

If anyone is using 1 1/2X1 16 ga tubing I would be shocked.........but then again?

You are correct tape is not a perfect system and when it has a problem it is a big PITA. With that said please remember that the aluminum is going to expand and contract no matter how it is fastened. As much as I hate white generic looking crap you will have less problems with a light color than a dark color simply becase of expansion from heat. With that said when the body is skinned I scuff pad where the tape contacts the panel and use a primer which seems to eliminate most of the problems.

Don't look underneath these trucks it'll scare the hell out of you.....

Randy

Does anyone know where to get this industrial adhesive tape? do they have it at home depot or is this a specialty item from a body shop or soemthing? Can it be ordered on line?

thanks,
Mike

I have a Race Coaches unit and they use Sikaflex dispensed from a caulking gun. Don't know the number, but I've bought other types of sikaflex online.

The aluminum panels have been on for more than a year and I drive the rig off road, so it seems to be holding so far.

The panels on our rig are also attached with SikaFlex. I believe they used #252. There were a few seam 'pops' right off the bat but it seems to be holding up well now.

see: https://www.sikaindustry.com/ipd-transoem-body