1959 Tradewind floor installation question

[gtr]

I am replaceing the floor on a 59 airstream. The interior was totally wasted as well as the floor. As you know the plywood was installed before the shell was so floor repalacement without shell removal is difficult. Does anyone have any good ideas how to reinstall the floor and tie it into the outer shell. I have removed all the rotted plywood carefully after removing the interior. I have cleaned, repaired and painted the frame with Por 15 anti-rust paint and I am ready to re-install the plywood floor. I will need to drill thru the plywood in the open areas of the floor and attach it to the frame with some type of fastener. Any suggestions??? The underskirt skin is still in good shape and I do not want to remove it so I do not have access to put bolts thru the plywood and secure it to the frame??? Aso I used a sawsall to cut the plywood loose from the outer edges where it went under the walls. The outer walls are still scurely attached to the frame with the original bolts that went thru aluminum base plate and the plywood into the frame on the outer edges. There is about 2 inches of plywood left under the outer wall aluminum base plates. I plan to use the old wood as a pattern and cut the new plywood to fit just up to the inside edge of the interior walls but I need a good secure way to tie the floor to the inner walls base plate so there is no sagging. Does anyone have any good suggestions??

[Ken J]

The only suggestion that I have would be to loosen the belly pan and reach up and put your bolts in the cross members. Since there are not that many perimeter bolts, you could drill holes large enough in the belly to be able to reach those bolts, then patch later. I'm not in favor of self tapping screws - and I think you need to get to those perimeter bolts somehow. Loosening the belly and putting it back is not that difficult. Hope this helps.

Ken

[Over59]

If you use self drilling screws get the ones with little wings if the floor is 1/2 or more, which it will be. Alternatively drill and use self threading screws. This is what I will be doing on my 59 overlander as I will be sealing up the belly from the top, filling every mouse hole, then insulating, then floor. This of course is not PC. I will also be using an epoxy filling adhesive between the floor and the frame. Check out these links for info. http://www.compassintl.com/section2/dartsrule.htm Your frame is more like 14 guage.

http://www.nutty.com/cgi-bin/shopper...&KEY=WT1024112

http://www.grabberman.com/slfdrill.htm

http://www.stainless-fasteners.com/s...ing_wafers.htm

There are other sites as well, I cann't find my self threading bookmarks. Do a search. I am leaning in the self threading direction.

You would find it less trouble to release the belly down the midline to work the elevator bolt method then you think. Then you could power wash the interior of the belly pan and get rid of all the crude. There are places like near the axel area that may be a challenge to get under for the bolts but in looking at mine, which is gutted, it looks like it can be done. However detaching it from the perimeter means drilling exterior rivets. And then tring to get it bakc in place to attach it. To me this looks like a major complication.


What's holding your shell up. The front plate holds up the front of the shell.

[malconium]

Mark,

I am replacing my floor with part of the belly pan in place. I am also doing it with the shell in place - supported with a simple framework that I devised that does not require that the body be lifted off entirely. I have also proposed a technique for replaceing the material around the edges if you want to do that first and then put the rest of the floor in between. I am attaching my floor with elevator bolts in places that I can reach from above in the places where the belly pan is still in place and using self-drilling/taping screws elsewhere. I am also using a plastic material instead of plywood that I hope will result in a permanent floor solution. Please check out the following threads for a lot of details.

Some information about the new material I am using for my floor
http://www.airforums.com/foru...ead.php?t=14620

http://www.airforums.com/forums/showthread.php?t=11818 (title = Body and banana wrap on floor replacement technique.) Look especially at the first post where I added a drawing. I am not using this technique but it still should work fine if you want to replace the band around the edges first. You would be able to access all the bolts from above too which was part of the intent of the approach.

http://www.airforums.com/forums/showthread.php?t=11814 (title = Shell Off vs. Shell On Summary) Look especially at my detailed progress report in post number 74. The bracing that I used there works great and does not require all that much in the way of materials. There are photos in my gallery that go along with that report. The technique does not require lifting the body entirely off of the frame - it just supports and locates it while you repair the floor under it.

Please feel free to ask me any questions about the various approches that I detailed in the above. I have tested out all the techniques except the one about installing a rim around the edges.

Malcolm

[Inland RV Center, In]

gtr.

Separating the floor periphery from the floor proper results in a tremendous loss of support for the shell.

To do that in a very small area, except the footstep area, is OK.

However, part of the shell weight is transfered thru the floor to the main chassis.

When that is severed, deletorious results are guaranteed.

The problem is that the resulting damage won't show up, until you complete the trailer, and then tow it. Then, you will have to start all over, "again".

Andy

[markdoane]

I would recommend a 'center seam' floor replacement.

You need to take out the 2" band under the floor channel/base plate. Then cut the new floor with a seam in the center, so that you can slide the plywood pieces in under the floor channel. Your overall plywood width will be 88". I used one sheet 48" wide and the second sheet 40", with the seam offset 4" to one side.

Use the 8" leftover strip to make a joining plate under the seam. You can lay the 8ft sheets lengthwise, so you have fewer crosswise seams to deal with. Do the corners first to avoid problems getting the sheets in place.

[Ken J]

I did exactly as Don did......

Ken

[malconium]

You actually can put the end pieces in cross-wise like the original if you want as long as you put them in first. It turns out that the curved shape will allow you to lay the sheet down flat on the frame on the diagonal and rotate it into position.

Malcolm

[Over59]

That piece used as a joint seam should be attached with filled epoxy. Marine repair sites have info on this. Screws are not enough and the seam will flex, bad for vinyl flooring. If you have seams treatment like wall broad seams, fill, sand, fill , sand. but the two pieces need to become one and stay that way when you hit a railroad track that's washed out at 50 mph.

PS Great Trailer.

[malconium]

The proposal that I outlined some time ago for putting a strip of flooring around the outside edge and then adding the floor in the center relied on there being a splice piece bolted and glued under the outer edge for the inner plywood to attach to. My intent for the approach would have been to use glue and screws to attach the inner pieces to the outer ring. As I mentioned I decided not to use the approach myself largely because it just did not seem at all necessary. I figured out that it really is not all that hard to get the new sheets to fit under the bottom of the wall even for the newer style u-channel/c-channel wall bottom construction. The only place I can recall having any trouble was one place where the bottom of the c-channel had been bent upward a bit. Once I got that corrected all went in easily enough.

Andy,

Do you have any estimates as to how much the body is actually likely to weigh with all the stuff attached to it? Obviously the old photo of a couple of guys holding a body up does not have the windows, air conditioner and etc. installed. I have been wondering just how hard the outriggers and floor panels have to work to support the load when the trailer is in motion.

Thanks,

Malcolm

[Over59]

Personally I think the floor works just as hard at holding the shell on as it does holding it up. At 70mph there is alot of lift / push going on. One of the engineer guys can figure it out, but that floor hold the shell on when traveling and I would bet the force up and back is move than the dead weight at rest.

[markdoane]

Originally Posted by malconium

You actually can put the end pieces in cross-wise like the original if you want as long as you put them in first. It turns out that the curved shape will allow you to lay the sheet down flat on the frame on the diagonal and rotate it into position.

Malcolm

Good point! I didn't think that one through.

[Ken J]

If you glue and screw the seam as Don suggests, it will be as strong or stronger than the plywood. I used Tribond (sp) II and epoxy around the edges - and painted the floor with Varathane.

Ken

[malconium]

Over59,

I can easily believe that you are right on that score. There must be a lot of lift off force trying to remove the body from the frame during freeway travel.

Does anyone know if there are structural engineering numbers available? Someone had to have done some calculations somewhere along the line and it would be interesting to know if anything has been published about the loading that the AS was designed for.

Malcolm

[Stefrobrts]

Don't you think the forces on the trailer in motion would be down forces? If you think about how the air will come over and around the truck, and then over the rounded shape of the trailer, I think the forces would be mostly downward. Not that that would excuse the need for a solid floor to frame connection.

[markdoane]

I think any coefficient of lift calculations would be very complex, due to the turbulence induced by the tow vehicle, and further complicated by the angle of attack due to various hitch heights.

[malconium]

Here is some food for thought:

I was wondering just how much load the body was applying to each foot of the bottom of the body channel. On my 31' AS I estimate that I have something like 65' of channel around the bottom of the body. So here is what that means:

Formula: body weight / 65' = lbs per lineal foot

if the whole body with its attachements weighs 1000 lbs this would work out to be 15lbs per lineal foot of channel. If the body and all of its attachements (windows, AC, wiring, etc.) weighs 2000lbs then it would be 30lbs per lineal foot. It is hard for me to believe that the body could weigh in at anything more than that (does anyone know for sure?). If I assume the 30lbs per lineal foot then that means that each outrigger end would be supporting 60lbs since the outriggers are on 24" centers. Since a lot of my floor is off I decided to try to get a feel for what an outrigger could support. With the body sitting on it I decided to see what would happen if I added my weight to it too. It was a good thing it did not break I guess. Of course I could not get my weight all the way out at the end but it did not have any trouble supporting my 230lbs and the body. That roughly means that just the outriggers can support at least 5 times the dead load of the body without any help from the floor.

So what kind of forces are needed to actually break an outrigger I wonder? I had one that was broken that was just in front of the wheel well on the curbside.

Malcolm

[Over59]

I remember seeing somewhere that Wally claimed the trailers weigh less on the road because the aircraft wing shape created lift and took some of the load off the axel, making for better gas mileage and easy towing. He was some kind of marketing guy.

I do know that if I don't tie my canoe on the canoe trailer that it well "fly" off.

My point was in installing new floors one must consider that they need to take into account both forces. One pushing down and one pulling up. As I have been considering self tapping screws this has caused me the most concern. Try standing in the back of the truck holding a 4x4 sheet of plywood while your spouse picks up speed. The front of an AS is more like 50-64 square feet.

Is this one of those square of the increase deals. Twice as fast gives you four times the force? I think it is. That's alot of force at 60mph. Maybe that's why elevator bolts are needed. The hold the whole thing to the frame and keep it from flying away.

[Inland RV Center, In]

Malcolm.

Out riggers don't usually break.

But they can and do fatigue crack because of lack of proper running gear balance.

As in your case, the fatigue cracking takes place near the axles, because of the vibration.

Andy