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A-Merry-Can 06-30-2005 05:52 PM

STEP-BY-STEP Shell-Off Floor Replacement
ok guys. first and foremost, i am NO EXPERT! in fact, this '59 traveller is my first trailer! my grandparents used to always take me out for the summer in theirs, and i knew i had to get one. i've always wanted to restore something cool, so here we go. i decided to do a complete shell-off frame up restoration. it's the only way, in my opinion, and if you saw my frame, you'd agree! i tell ya, i have learned more with a pry bar and a saw in my airstream than anything i've read so far. i know a lot of you guys have done the complete shell-off restoration, and i wanted to run my plan by you all for feedback to hopefully steer me clear of any uncharted dangers!

here's my plan (i've already made it through the first couple of steps, but i'll put them in anyway for others).

1) remove complete interior cabinets, furniture... down to the bare shell.

2) remove 4 pieces of bannana moulding

3) drill out rivets connecting the belly pan to the body & drop pan

4) remove sub-floor (mine was so rotten, it practically pulled out by hand)

5) after i removed the subfloor, i had to use a cut-off disk to remove all the rusted bolts that held the floor on. (this is where i am with my '59 at the moment)

6) cut off all bolts from the shell to the frame.

7) build temporary bracing for the shell, once it's lifted (i plan to use x-bracing both vertically and laterally, with additional support along the body line of each side).

8) drill out rivets holding wheel-wells to body shell, and remove wells.

9) lift shell (with several friends and a jack?) above the frame and set on temporary saw horses.

10) pull frame. weld in replacement cross-members and outriggers, if neded (mine needs 3 of each). i also plan on welding the nuts to the shell that hold the shell on, so i don't have to access them once i put the belly pan on. sandblast the frame, epoxy prime, and final coat with silver.

11) replace axle and suspension with new.

12) install grey and black-water tanks in the frame if they are below the floor (this is all guess. my trailer was completely gutted when i got it, so i'm not 100% certain how the plumbing went in.)

13) cut wood floors using old as patterns (if only i COULD!) i'm going to have to guestimate mine. i'm planning on making a pattern BEFORE i lift the shell to make sure the pattern is correct.

14) reinstall wheel wells and splash guards.

15) install weather-proof insulation over the top of the frame rails

16) install new floor with new elevator bolts (i want to find an alternative to plywood. i don't want this thing ever rotting again!)

17) install center belly-pan piece first, then the 4 corner pieces, moulded to the shape of the floor.

18) drop shell back on, and install bolts into the frame. also, install wood screws between frame bolts.

19) line everyghing up, seal and rivet-away.

now the fun parts begin! :lol: seriously, though, is there anything wrong with the order i have listed above? also, if anyone has any tips or what-not, i'd love to hear them! i'm planning on digging in saturday morning and HOPEFULLY getting the shell off, and the frame ready to weld.

thanks a million for any advice!


desi arnaz 06-30-2005 06:39 PM

try trex for your floor..........take a 2x6 and split it down the center............2 for the price of one.i did this in my boat and have had no problems[3rd floor]

Ken J 06-30-2005 08:26 PM


I would/did use ACX plywood - epoxy the edges, paint the rest with water based Verathane.

Ken J.

Over59 06-30-2005 09:42 PM

I'm not seeing if you are removing the inside shell to remove the old fiberglass insulation. This is the source of much smell. Do it before you lift the shell and it will be lighter. Wear a mask, you don't want to be inhaling dried mice dirt when you take the interior walls off. I think this is essential when you are going to all the trouble to do a shell off.

I don't understand the bolt thing and weldnut or wood screws. You will need an attachment from the floor to the shell and belly pan. A 1.5 x 1.5 bent piece of sheet aluminum will work. This is attached to the floor / out rigger with elevator bolts. Between these I used full thread 1" deck screws, drilled 1/8" holes in the aluminum to start them.

Have you gotten past the hidden rivets? These attach the belly pan to the ribs up under the exterior shell. Nasty surpirse. The shell lifts easily if "all" the rivets are out. Vulkem may give some sticking between the well wheels and shell.

I don't think you ever had a grey tank and maybe not a black tank. Plan ahead. It you are replacing cross members then check tank depot for tanks that you could use by moving the position of the cross members a few inches. A lot cheaper than custom tanks. You could also use a single grey / black tank.

Do you have trim over the wheel well shell line. These have some hard to find rivets also. If something doesn't move with alittle force look for rivets. The old guys that put these together are sitting in the nursing home laughing their .. off thinking about blind rivets.

Save a template of the belly pan around the wheel well, how it comes up to the shell.

5/8 marine plywood is more than enough, just treat it like Ken. If you use another thickness then things start to not line up.

Good Luck.

PS. how many cross members do you need, I had some made up and didn't use then all.

A-Merry-Can 07-01-2005 07:09 AM

great info so far!
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wow, thanks for all the great info so far. i had planned on marine plywood as a back-up. i'll stick with that. what thickness is the wood? 3/4"?

also, thanks '59 for all the great tips. in fact, i have drilled out the rivets for the front belly pan, and it didn't drop. i assumed it was sealant of some kind. tell me more about these hidden rivets, and how the heck i can get to them! frustrating to say the least. :mad:

the welding the nut to the frame idea came to me when i tried to understand how these shells were attached. i assumed the belly-pan needed to go on before the body? (let me know if this is wrong). anyway, with the floor in it, as well as the belly pan, i didn't know how to attach the shell, other than to have the floor pre-drilled over the frame outriggers, and have the nut welded to the frame. then i wouldn't need access to the underside to tighten them. it could all be done from above. i'm not sure i understood where the aluminum piece would go that you mentioned?

then i looked at my trailer a little closer, and it SEEMS like when i take out all the rivets at the bottom of the shell, top of the belly pan, the channel that supports the base of the wall comes out. now this opens up another option for me. can i drop that channel, and fasten it to the sub-floor, and THEN drop the shell over the channel and rivet it back on?

good tip on removing all the interior. i just have the lower interior removed at this point. i am planning on replacing all the insulation for certain, but i left it all together thinking it would make the shell a bit stiffer when i remove it. lighter works for me, though.

speaking of lifting the shell, as i understand it, i attach my wooden braces directly to the internal ribs with screws. i had planned on supporting the footer of each side on another 2X4, but if that lower channel piece needs to come off, i guess i could lift the shell by the 2X4s. will the ribs be strong enough to support the entire weight of the shell with just wood-screws in the sides? how much should a totally stripped 15 foot shell weigh?

finally, i haven't started drilling out the wheel wells. that was on my list of stuff to do after work today.other than the 25 rivets i can see from the outside, are there others i shoudl watch out for? i'll attach a pic.

as for the cross-members, i had 2 made already, and 4 outriggers (still need to radius the ends). i think that will be enough, but something tells me when i sand-blast the frame, i'm going to find other sections of weakened metel that will need attention. always gotta plan for the worst. :D

thanks again for all the info! i don't know HOW i would figure all this stuff out on my own! ha!


fireflyinva 07-01-2005 07:54 AM


I wonder if you might reconsider taking the shell and the belly pan off--It seems that you only want to weld, and that can be done with the shell & belly pan on.

I have to admit, I'm a bit leery about pulling off the shell--it just seems to open up a whole new range of complication and possibilities for damage. Plus, I've noticed around here that there is a much higher likelihood that folks quit on a project with a shell-off instead of keeping it on. So, when we had to start structural repairs last spring, we decided to go the shell-on route (and we are doing many of the repairs you mention).

We've done quite a bit of welding of trailer frame members from the inside with no problem. You also don't have to take the shell off, even for the outriggers. Same for new tanks. Really, the only reason I can think of where you absolutely have to remove the shell is to remove and replace the trailer frame.

Regarding the belly pan, in our era of trailer, the attachments held both the bellypan, shell and floor on together in a rather complex clamshell arrangment. You can't attach any of these independent of the other two elements. I'm not sure about your planned sequence--it appears a bit out of whack for replacement (I'll have to work this through a bit more).

For belly pan issues, the preferred technique (again, for this era trailers only) seems to be to cut it out below the line of sight. But why cut it out, unless you plan to have something (like a tank) hang at lower clearance? And then, even if you do add in a tank, all you really should need to cut out is the affected location, not the whole thing.

BTW--you may want to consider cutting out the floor in sections, so you can still have a bit of a platform for working on the innards, then you can cut it off, section by section to replace the flooring.

I hope you don't mind my devil's advocate questions. There are folks here who have done lovely jobs with full shell-off efforts. But I think they would all admit that the job was huge--and all I wonder is, why bring on that extra effort if you don't need to (since the effort really doesn't seems to offer any meaningful advantage)?


greg176 07-01-2005 08:09 AM

The plywood is 5/8". The belly pan is held on with more rivets up underneath the lower panels.The belly pan was riveted to the lower "U" channel at the factory before the shell was installed.If you remove the inside lower panels first you will be able to see where those rivets are.

A-Merry-Can 07-01-2005 08:14 AM

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i hear ya on this being a time consuming effort. it seems like every day i work on it, i add a few weeks to my estimate! :-D i foolishly thought i'd have the shell off, new floor and pan, and shell back on in 4 weeks. it still might happen, but we'll see.

the problem with my trailer is the guy i bought it from had already started cutting it apart, so i can't tell how a lot of things went together. when i got her, the rear floor rear belly pan, interior and all plumbing was out of it. the reason i want to do a full shell-off restorations is the amount of rot i keep finding. i'm kinda picky when it comes to rust. my plans once i get the frame out is to sand-blast it all, weld in new cross members, outriggers, and fix any other stuff that shows after the blasting, then epoxy-prime it (several times!), and coat it all with a nice thick silver coat. that should hold the rust at bay. i know it seems extreme, but i want to be able to enjoy this trailer forever! :D

i'm not saying the shell off/on is better or worse, but in order to put everything back as it originally was, it seems like the most complete solution? if nothing else, it's an interesting learning experience, to be sure. it seems like after going to all this trouble, lifting the shell completely wouldn't add too terribly much to the over-all job. especially considering it's a shortie. i knew shorter was better! ha! do you have any input on the installation order? i would love to hear feedback on attaching the floor, belly pan and shell together in one step.

i'll attach a pic of where i am at the moment. things will look a lot further along after this weekend. i am concerned about hidden rivets, though. i'd rather not remove too many external panels, unless totally necessary.


C Johnson 07-01-2005 08:18 AM


then i looked at my trailer a little closer, and it SEEMS like when i take out all the rivets at the bottom of the shell, top of the belly pan, the channel that supports the base of the wall comes out. now this opens up another option for me. can i drop that channel, and fasten it to the sub-floor, and THEN drop the shell over the channel and rivet it back on?

Now your catching on !

greg176 07-01-2005 08:29 AM

If yuor trailer has the steel plate in the front the belly pan wraps up underneath the two rows of rivets on the front panel below the window.
Looks like great progress.Glad to see you are doing it right.Do you have your elevator bolts yet?If you are planning to install a grey water tank under floor now would be a good time to order one.That delayed my project about two weeks last year wile I waited for tank to arrive.

A-Merry-Can 07-01-2005 08:32 AM


Originally Posted by C Johnson
Now your catching on !

ha, like i said, i learn more with a crow-bar and a saw than reading! :D i just checked out your project site. very cool! i take it you didn't remove the shell? did you mount the black water above the floor? i think that was original in that model. i want to try to mount mine below the floor, if it doesn't cause massive nightmares.


greg176 07-01-2005 08:42 AM

There are several great posts on grey tank installation.I have posted a few pics of my install.Do a search for FRAME REPAIR. UWE made some amazing tanks do a search for his thread "a 63 for me".
Markdoane did a great installation here

cynthia 07-01-2005 09:24 AM

Stop! Wait!
No one adviced you to drink a BEER first. Good luck and have fun,chance are you will only do this once.

MarkR 07-01-2005 10:16 AM

I'm at the same point as you with lots of the same questions, like the "putting it back together sequence" - Kind of baffling to me. It seems like it would be easier if the bottom channel of the walls was attached to the body/skin so you could "drop" the body onto the deck and screw it down . . . but instead it looks like I'm going to have to carefully try and line up (blindly in my case because of a new belly pan) the original rivet holes. Just seems like if the channel was positively attached to the body it would be easier . . .
And in case you didn't find out yet, I found a thread somewhere along the way that estimated the body for my trailer 21' (18' body) weighed something between 400-500 lbs, which seemed high but now that I'm all "detached", it feels about right.
Thanks for you posts. Mark

Over59 07-01-2005 01:35 PM

Some of those belly pan front plate rivets may be blind, that is not through the skin. You shouldn't have to take any exterior panels off. You may need a rather heavy duty putty knife style scraper to slide up between the rib and belly pan and with a hammer shear the rivet off. There should be a hidden rivet on each side of the door on the ribs and on each end of the well wheel.

Use the 5/8 plywood. I used 3/4 and it wasn't necessary. What are you painting the frame with.

A-Merry-Can 07-01-2005 03:32 PM


Originally Posted by MarkR
I'm at the same point as you with lots of the same questions, like the "putting it back together sequence"...

you and i definitely need to share photos of what we discover along the way! ha! thanks for the weight info. this evening, i'm planning on building the wooden body braces. i plan on spanning the set of ribs right at the end cap on both sides, then another one over the wheel well. since the bottom aluminum channel has to come out, i assume i can temporarily lift the shell from the ribs, but then store it with a temporary wooden footer, so as to not stress the body for the 2 weeks (month?) the shell will be off. :D

i need to trace my patterns for the floor before i lift it this weekend, though. i hope i'm not missing anything!


A-Merry-Can 07-01-2005 03:35 PM


Originally Posted by Over59
Some of those belly pan front plate rivets may be blind, that is not through the skin.....

thanks for the tip as well. i will try that next. one problem i can definitely foresee is the rivets behind the LP tank mounts. i can barely get to them as is. i think i'm going to have to dremel the heads off the rivets and hope for the best. if i have to smack something up from the bottom in that area, i won't be a happy camper! :mad:

as for paint, i'm not certain yet. a good friend of mine has a spray booth, and i was planning on putting on a thick coat of single stage epoxy (i think that's what he said), and baking it on, then a nice thick coat of silver. if you have suggestions there as well, let me know and i'll add them to my growing notebook here!



markdoane 07-01-2005 04:22 PM

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The hidden rivets i discovered, in addition to the ones mentioned by Over59, were in the corners, where the ends and the sides meet.

C Johnson 07-02-2005 01:32 PM

Hi Jordan, No I didn't remove the shell. Didn't see the need for it and I am not equipped to do so anyway. It came out really well. I used the old floor pieces for patterns. Everything fit back together perfectly. I had a new black tank made and I am putting it back in the same spot. The gray water tank is a blue boy, since I boondock more than anything, it just easier for me. I made all the plumbing Valterra, much easier to get than Thetford, FYI

A-Merry-Can 07-02-2005 03:27 PM

assembly sequence
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ok, i had to illustrate this as clearly as i could. i didn't know exactly how the belly pan was attached. a few hours with a cut off disk, a pry bar, and a few beers, and NOW i get it. i couldn't figure out why the pan wouldn't just drop when all the rivets were removed. it seems on mine (and maybe it's this way on every airstream, i don't know), the belly pan is folded over the "C" channel before the body is riveted on. this is a ton of work, but very rewarding. the best thing about a true shell-off to me seems to be that you can build them back literally like they were made the first time.

anyways, it's ridiculously hot out, so after sweating my bollocks off all afternoon, i decided to do some simple 3D renders of what i found out, in case there were other confused first-timers out there (like me!) i'll post pics of where i am on the trailer later, once i get them all sorted off the camera.

on to my reassembly sequence.

Step 1: renew frame, axle, etc (pic 1)

Step 2: install sub-floor (insulation not shown for simplicity)

Step 3: install outer channel, and bolt through to outriggers (pic 3)

Step 4: wrap belly pan from underneath, and fold over the top of the channel (something tells me i'm going to need some bandaides for this step!)

Step 5: drop body back on with shell frame, and rivet the whole lot together. no hidden rivets for me, just in case 45 years down the line some other idiot decides to restore this baby! :D

time for another beer!


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