good place for seams for a shell-on floor redo

[greenrig]

55 FC shell on subfloor replacement. i have the interior panels off and floor out but there will have to be seams somewhere. some will land on frame and outriggers but in order to keep shell on and get the floor properly under the shell, more seams will have to be made. any good links for this?
thanks, thanks!!

[VIKING]

I don't think you need any more seams than it had originally.
I just did this on my '64 Safari and I'd be glad to help you figure it out.

Send me a PM and if you want I can come take a look at it this weekend if it's in Santa Cruz. I would love to see any '55 for that matter.

Rich the Viking

[greenrig]

pretty sure 'shell-on' means more plywood butt seams than original in order get the plywood under the bottom plate and fastened properly. unless you can bend 5/8" plywood with super human strength?

[VIKING]

Shell-on really becomes shell-off at some point, in that you have to remove the fastners that attach the shell to the floor and frame to slide the new floor under the wall. Not that you actually have to lift the shell off. You just have it sitting there loose at some point. This allows a lot of flex in the shell, and you can actually push the walls out. Also, the seams can all be rabbetted into each other like the original for more strength, rather than butted seams.
I'm far from super-human but I did this all by myself. click on my blog link and you will see some of it. My offer of help stands. I'll be away from the computer for the weekend, but I will PM you with my phone number if you want to get together.

Rich the Viking

[greenrig]

thanks, i see how you have your new peice of plywood wedged in ready to be forced down and expand the original outline of the airstream at the floor (bottom plate). and all the while, supporting the shell on your jack. did you just tap the plywood down in? so if you can manage to get one side in (under bottom plate) which is about an 1 and a half, then you stretch the other side an 1 and a half? just playing devils advocate here, but doesnt all that stretching break exterior seams and tweak/expand rivet holes or even pop them? i would feel more comfortable scabbing and rabbiting a new seam down a line where there is no foot traffic weight, splitting the peice in half and removing the need to tweak and stretch and jack?

[greenrig]

on edit: one and half inches (on each side)

[Aerowood]

I replaced my floor shell on also. The walls will flex enough without any detrimental effects to rivet holes structure etc, if it would have I would not have done it. I did it in this order on replacement. Aft sheet first, then sheet in front of that then the most fwd sheet working my way aft to the previously installed sheets.
http://www.airforums.com/forums/f416...nte-26902.html

Kip

[VIKING]

I did mine front-to-back and the last piece was pretty easy because I had a cut-out where the water heater came through the shell right at the last seam. That made it fairly easy for me to get the last piece in. If I didn't have the hole there I would have put a middle piece in last.

Rich the Viking

[Minno]

We did the back 2 pieces first, then front to the wheel wells - 7 4x8 sheets in all. We kept them whole and flexed the walls out. Just be sure to keep the c-channel on the outriggers when you flex. If they come off it's more of a pain to get them back on top and in correct alignment again. The biggest thing to figure out is how to get the plywood into the trailer and positioned so you can slip them in. We put the street side up, door/curb side down, then started the plywood into the right spot on curb side, brought the street side down as we did so and flexed the walls out to fit it in. It was a challenge for me since I'm so short (well under 5ft tall), so Chris took more of the lions share of the weight. I think the bruises have finally healed...

Kay

[VIKING]

A little more info.
The seams in my original flooring were overlapping rabbet joints with about 1" overlap, so the sheets were made 49" wide to maintain the 48" spacing to align with the framing members. The closest thing I could find at a reasonable cost was 5/8" exterior smooth face siding with 1/2" rabbets. You can find this at any home improvement store. These are 48-1/2" wide sheets, so you maintain the 48" spacing.
The original seams were not glued, and this is a cause for concern because when I removed the original there were seams at the doorway where the water had gotten into them and traveled about 3 to 4' towards the center of the floor. The wood was rotten through in that area in a big way, so when I re-did it I glued the seams with Titebond 3 waterproof glue to eliminate this from happening again. I glued the seams, slipped the sheets together, and ran 5/8" pan head screws through the rabbets to pull the seams down flat while the glue dried, about every 6" or so. Then when the floor was all in place I drilled and bolted the floor down and removed the screws.
I also treated the bottom and edges of the sheets to give them some protection from water in the future. The bottom side of each sheet was coated with water-based floor finish, and the edges and about 6" of the top perimeter was primed and painted with exterior latex paint.

After seeing how the water had traveled along the seams I would not do this with butted seams in any case, unless it was for a small repair only.

1 more thing, I was able to do all of my floor without removing the part of the bellypan that's buck-riveted to the bottom edge of the shell. I didn't want to have to resort to Olympic rivets, and I had no helper to buck them if I had to, so I worked around them without having to drill out those bucked rivets, and I was still able to bolt the entire floor down.
I know that not all Airstreams can be done that way due to the different ways the bellypan was made on different models. I was fortunate. Maybe you are too.

Rich the Viking

[greenrig]

thanks for all the input. i appreciate it! very helpful.