Coast Resorts Open Roads Forum: Avion truck campers

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Topic: Avion truck campers - Hundreds of photos

Posted By: 69 Avion on 07/08/12 06:08pm

BlackFlagForge wrote:

yea its crumbling off like potato chips

We had quite a bit that we couldn't get off.
We used Plasticoat Aluminum Alkyd Roof Coating. We ordered Heng's, but they sent Plasticoat. I think that it is the same stuff. Cayo said that it is as close to the original as you can find.

Ford F-350 4x4 Diesel
1988 Avion Triple Axle Trailer
1969 Avion C-11 Camper

Posted By: 67avion on 07/09/12 09:16am

I was very interested in the discussion of the framing of the rear overhang on the Avion. But, to say the least, I have a very limited knowledge of the fabrication. I reached out to a Forum Member that I really respect, SoCalDesertRider, and asked for his opinion. He gave me permission to share this with our Avion crowd:

"Hi DG, I saw some of the computer drawings of the c-channel frame to be built under the camper floor. It appears to be intended to support the rear overhang floor of the camper.

2 changes I would make.

First is to extend the main to longitudinal members of the frame so they go all the way back, the full length of the floor, continuous. The point where they stop at the end of the truck bed and connect to the lateral member causes a lot of loss of strength of the frame to support the rear overhang. Just extending those to main members all the way to the rear will benefit the frame strength quite a lot.

By breaking up the frame right at that critical juncture at the end of the truck bed, the strength of the frame behind that last lateral member is dependent entirely on that lateral member's ability to resisting rotational twisting force in the vertical direction, since the longitudinal members that continue on behind it are not in line with main 2 longitudinal members of the front section of the frame. Having 2 continuous longitudinal members eliminates the vertical rotational twisting force on that lateral cross member, by eliminating that member from the frame. It is no longer needed, if the main 2 longitudinal members continue, uninterrupted, from the front all the way to the far rear end of the camper.

Second change I would make is to use tube instead of c-channel. Tube is stronger than channel per weight per foot, especially when the channel is turned flat. Channel is inherently strongest when the legs point to the side and web is vertical. With the legs down and web horizontal, a lot of the strength of the channel is lost in the vertical direction. Square or rectangular tube (with the long side positioned vertical, if using rectangular tube) would be stronger, if using the same weight/foot section size as the channel, or same strength but lighter, if using a smaller weight/foot section size."

Posted By: BlackFlagForge on 07/09/12 09:34am

Extending the mains all the way to the back has changed on my plans but I have yet to update the images. With the number of comments made about changing the channel to tube or rotating it I am going to do something different but we do not have the space available to rotate a rectangle tube on the vertical so I'm not sure yet if it would be worth the weight to use the 3"x1" rectangle when it might only have the strength of square stock of the same thickness. The reason I was tempted to use C-channel at the start was so that I could hang mounts for any tanks or other ideas that might come up later and I still might go back to that concept, right now I'm mostly broke and spitballing while I do the little things like leak and wood repairs. Everything at the moment is on hold thanks to Fastenal and my trempro 635 being held up for the last WEEK at the hub and not shipping to my local store.. thanks for that.

Posted By: BlackFlagForge on 07/09/12 11:08am

This was the last idea I had drawn up but still not 100% on the tube/channel yet, but for reference this is 2"x1 1/2"x1/8" rec.tube and using 40' total weighs around 110# not including the two 2x4 stingers for added support.

I'm a fan of doing things beefy so the idea of 1/8" walled tube is not so comforting but the weight here is the issue and I feel that this should only be a bonus to the other weight bearing structures and need not support the full load of the rear end.

I'm not sure about how much shear force will be applied from the frame to floor so I am a bit lost as to how I want to secure the two together, the first thought was from interior floor into the structure below or some L-brackets welded to the frame that I could then screw into the flooring, maybe a combo of the two would work best, thoughts?

I added in the voids and pipes on my 69 where the tank/plumbing/electrical penetrate the floor so this layout is accurate.

* This post was last edited 07/09/12 12:32pm by BlackFlagForge *

Posted By: BlackFlagForge on 07/09/12 12:25pm

This is my idea for the stairs, I plan to use 1x6 stained and treated to keep things light with just a bit of ironwork for the connection.

* This post was edited 07/09/12 12:36pm by BlackFlagForge *

Posted By: ticki2 on 07/09/12 12:50pm

BlackFlagForge wrote:

That is a much better layout than your first . I think it can be made stronger for the same weight by eliminating all the lateral ties under the tub area except for the very back piece . Then add a third runner in the center running all the way as the other two . If they are attached to the floor , the floor will act as the lateral support . I think you a correct in assuming the steel is only additional support and not full support as the upper structure will still be doing it's job . Keep brainstorming , I think you will eventually come up with a very nice system that will be copied by others .

'68 Avion C-11
'02 GMC DRW D/A flatbed

Posted By: ticki2 on 07/09/12 01:07pm

BlackFlagForge wrote:

This is my idea for the stairs, I plan to use 1x6 stained and treated to keep things light with just a bit of ironwork for the connection.

My steps are very similar and are working great . I used 1x8 redwood for the treads and stringers with the treads mortised into the stringer and then glued and screwed . It is light ( 13 lbs ) and strong . I made it an inch short of the floor distance from the door to the little cross wall at the dinette so it slides on the floor for travel . The only real difference between mine and yours is the way it hooks to the camper . Mine hooks to the one pull out step still on the camper and I used 1x8 ( which I would suggest )

[image]

Ignore the mess in the pic...long story

Posted By: BlackFlagForge on 07/09/12 01:36pm

The lateral ties are just 2x4, I thought about adding that central runner but its 11 more feet of steel to the weight and cost, most of the tube steel I buy is in 20-24' lengths, I would hate to buy another 20' only to use half, maybe if it was a more common size.

Posted By: 69 Avion on 07/09/12 04:41pm

BlackFlagForge wrote:

That is a much better layout. Square or rectangular tubing would be better than the structural channel layed out on it's side. Sturctural channel with the web vertical will probably be stronger than the equivalent weight rectangular tubing. Keep in mind, structural channel isn't the same as "C" channel. With the structural channel, the flange is much thicker as it goes towards the web. Unfortunately, you don't have the room under the camper to put the structural channel in the vertical position. Square tubing (ex. 1-1/2' x 1-1/2" would work, but it makes it hard to connect to the camper. That is why I suggested 1-1/2" x 1-1/2" x 3/16" angle iron. For it's weight, it is fairly strong, easy to mount and will layout nicely with two layers of wood runners next to it. As stated above, running the frame, straight back is the strongest, but it won't allow you to put in your plumbing. You can address the rotational forces by bracing the rear part of the frame as it goes around the camper. The real question is, "how strong are you trying to make it". I just put the internal braces in, and I'll bet that it will never break. It hasn't broke yet, and it is 43 years old. When I put my stainless steel gray water tank in, I meant it to help stiffen up the back end. It appears to be doing just that. It isn't as strong as a full lower frame, but in order for mine to now break, it has to vertically shear off several #8 screws and tear off that part of the wing in order to do so.
I just put in 1/4-20 stainless steel bolts into a 3/4" x 1/8" angle iron to pull the tank lip up into the lower wood. These bolts go through the upper 2" x 2" x 1/8" angle iron that is on top of the floor and competely hidden by the cabinet on the left side and the furnace on the right side.
[image]

A picture of the reinforcement piece before as it was being slid behind the closet/cabinet during installation.
[image]

You can't see the angle iron reinforcement behind the cabinet. Nobody would ever even know if was there unless they opened the closet and saw the angle iron instead of the 1" x 1" wood blocks that used to be there. The Rustoleum Hammered paint looks much better than those wood blocks did.
[image]

If you are going to use 2" x 1" rectangular tubing, make sure you put the 2" side vertical.

Posted By: 69 Avion on 07/09/12 04:51pm

BlackFlagForge, I wanted to show you the difference on my mounts.

Left side factory mount.
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Right side mount. This is the one that I recall my dad strengthening a few decades ago. Notice how far the pipe goes back and how far it sticks out to the side. It has never bent since it was changed. It does require clearance to fit above the bed of the truck. I had to put an 1-1/2" extra spacers under the camper for it to fit. That is just about the same as you would have with your frame idea.
[image]

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