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Aviator · 01-17-2014, 04:50 PM

I just had a nice stainless hold down plate made for my shell of floor repair. The PO had all ready mucked around back there and I am not sure the proper order for the parts.

Frame, then plywood floor, hold down plate, then "C" channel

or

Frame, hold down plate, plywood, then "C" channel

It looks like it was frame, plate, wood, "C" but I am not sure.

Thanks

barts · 01-17-2014, 07:34 PM

This is what I did for ours....

=- Bart

Aviator · 01-17-2014, 07:54 PM

Thanks, Bart. That is where my thoughts were headed as it provides moisture protection for the wood. I just didn't want to mess it up when Iv'e gone to the trouble of taking the shell off.

barts · 01-17-2014, 11:30 PM

I can understand that... I snuck ours in w/ just a bathroom floor replacement in one heck of a hurry to get ready for a several week trip.

One of the key things is that the stock tie down in the back of the trailer was just to the C channel; I found this very weak. I added a row of rivets that picked up the stock skin, the additional skin I added and the stainless plate. The skin on our trailer at the C channel was/is quite corroded, so those rivets made a big difference in strength since they were in nice strong material.

- Bart

Aerowood · 01-18-2014, 09:28 AM

I did it the same way as Bart except I extended the hold down plate to the ouboard side of each of the vertical ribs, and then added an angle clipping the vertical rib to the "C" channel all the way down through the frame cross member. One other thing I did was to route the bottom of the plywood for clearance of the hold down plate. This let the ply set flush and not ramp up at the rear with the extra thickness of the hold down between the ply and the frame.

TTFN

rippie · 01-18-2014, 10:21 AM

Like Bart, I added some reinforcement/protection(in picture is painted white and not completely in place yet. This sheet was added to provide an external barrier for the plywood. My back end was so rotted and messed up I wasn't sure what was original or repair or what. But the hinge of the bumper box was attached to a strip of Alum(almost disintegrated) that slid under the ply. This created a water flow to the ply that I feel was the main reason for rot. So this sheet is intended to shield the ply back there. In effect it amounts to extending the skin to the bottom of the crossmember. This will also be the front of the bumper box.

Bart, I know you gave the disclaimer of being not to scale, but is the hold down angled like that. I never inspected mine that closely, but I thought it was just 90 degree angle. Maybe mine is aftermarket.

AeroW, I had wondered about notching out a place for the ply to sit flush. Makes sense (of course too late for me to do it now. Next time!)

Good stuff.

barts · 01-18-2014, 11:23 PM

The plate sits flat on the frame and lies against the back of the trailer; I carried it up a ways longer than stock. Mine is definitely at an non-90 angle...I made mine out of 18 Ga or so stainless; since I don't have a sheet metal brake the bend is a little ... informal.. but it's all hidden now

.

- Bart

Aviator · 01-19-2014, 05:37 AM

Thanks to all. I too have extended the width of the hold down plate. My new floor is Marine grade ply which has then been sealed with WestSystem epoxy. I also plan to add a thin secondary barrier around the edge of the wood (I guess it would be a third barrier if you count the epoxy as well) just for additional protection. My plan is for the next owner in 40 years to jump on the bumper and say, "Wow this is solid!"

80BELLA · 10-07-2017, 03:05 PM

I realize this is an older post...but I have a few questions. With the additional aluminum for reinforcing, would it be possible to bend it out so that the storage area lid has something to attach to? (see pic, modified version of Barts)...or is this too severe a bend?

It seemed like a lot of work to get my rear hold down plate off and even though there is a lot of corrosion, it is still a pretty solid piece of metal. If it lasted almost 30 years without any protection and that troublesome aluminum piece underneath it...shouldn't I be able to get another 30 by reusing this plate (that already has holes in the right place) and apply POR or RustBullet?

barts · 10-08-2017, 04:32 PM

Quote:

Originally Posted by 80BELLA

I realize this is an older post...but I have a few questions. With the additional aluminum for reinforcing, would it be possible to bend it out so that the storage area lid has something to attach to? (see pic, modified version of Barts)...or is this too severe a bend?

It seemed like a lot of work to get my rear hold down plate off and even though there is a lot of corrosion, it is still a pretty solid piece of metal. If it lasted almost 30 years without any protection and that troublesome aluminum piece underneath it...shouldn't I be able to get another 30 by reusing this plate (that already has holes in the right place) and apply POR or RustBullet?

Note that the key is to keep the water from wicking underneath the plywood. Your pic looks like it would work, but beware around the ends so that water has a place to go that doesn't get to the wood.

As regards to reusing that plate, if it's in good shape, use it. Mine was completely rotted out under the ply and where it attached to the skin.

Note that on our trailer the only rivets connecting the skin to the rear hold down plate also went through the C channel. This area was in very poor shape, with the skin corroded to the point where many of the holes had torn out. Drilling a set of rivet holes at the factory spacing about 4 inches up and bucketing in rivets let me tie the stainless hold down plate to the skin in a very secure manner; with stainless hold down bolts securing the plywood and C channel to the frame, it's not going anywhere.

So:

1. Keep the water out. Water runs downhill or sideways, make sure you're not relying on a dam of caulk to prevent disaster.

2. The rear hold-down plate ties the back of the aluminum skin to the frame. The stock rivets in the C channel are in a vulnerable place because they see a lot of water, and rivet steel and aluminum together. If this area is still in good shape, go ahead and do that in the stock manner - but get rid of that plate that goes underneath of the plywood.

- Bart

Daytonacoupe · 08-17-2021, 05:51 AM

Quote:

Originally Posted by barts

2. The rear hold-down plate ties the back of the aluminum skin to the frame. The stock rivets in the C channel are in a vulnerable place because they see a lot of water, and rivet steel and aluminum together. If this area is still in good shape, go ahead and do that in the stock manner - but get rid of that plate that goes underneath of the plywood.

- Bart

This is an old thread but it contains a lot of great info so I'll give it a try with a question.

My 1987 has no hold down plate front or rear. The shell is off. The front plate will be welded to the frame. For the rear curve my C channel captures the floor top and bottom - it's not the type that goes on top of the floor front and rear. I'd like to bend a piece of stainless or heavy aluminum to insert under the floor and C channel and up the wall at 107 degrees as per the drawings in this thread. But, the C channel and floor would sit on it, raising the floor slightly off the frame in this area, which would create a gap and compound the water ingress, would it not? I've considered cutting the C channel bottom out for the area where this piece would slide under. The floor may or may not have to be routered with the C channel gone. Just wondering if anybody has words of wisdom? Confused with the comment about getting rid of the plate that slips under the plywood where the drawings have the plate going under.

Thoughts?

barts · 08-18-2021, 11:22 AM

Reading my post, I certainly wasn't clear, was I? The plate you really want to get rid of is the one to which the bumper compartment top is hinged. This sends water right to the plywood. and it just sits there.

The slight raise in the floor due to the angled plate going underneath hasn't caused any problems afaict. You'd have more of a lift due to the channel being there as well, but I still don't think it will hurt anything. The frames in these Airstreams aren't that level, anyway

.

This area is weak in older Airstreams. Keeping the water out and adding strength are key ideas in rebuilding the back end.

hth -

- Bart

Daytonacoupe · 08-19-2021, 06:46 AM

Quote:

Originally Posted by barts

Reading my post, I certainly wasn't clear, was I? The plate you really want to get rid of is the one to which the bumper compartment top is hinged. This sends water right to the plywood. and it just sits there.

The slight raise in the floor due to the angled plate going underneath hasn't caused any problems afaict. You'd have more of a lift due to the channel being there as well, but I still don't think it will hurt anything. The frames in these Airstreams aren't that level, anyway

.

This area is weak in older Airstreams. Keeping the water out and adding strength are key ideas in rebuilding the back end.

hth -

- Bart

Right on; happy you saw this and nice of you to take the time to clarify. I'd be lost without the generous resources (time) offered by the community - lots of great guidance on 'how to'. I may have been overthinking the slight interference from an aluminum plate being placed under the C channel and floor, which I prefer to do vs bolting a narrow horizontal flange onto the top of the C channel.

Daytonacoupe · 10-01-2021, 05:46 AM

I'm finally ready to bolt on the rear end plate, which will side under the C-channel and on top of the rear frame X member. It's 1/8" aluminum bent at the 107 degree angle. 48" wide and 16" high. The 48" width extends a few inches beyond each of the two main ribs at the back, and the intent has been to capture the ribs to add extra reinforcement.

If anybody who has done this is still following the thread, it's just occurred to me that if I drill out the vertical run of buck rivets that affix these two ribs at the back to the rear panel, and insert a 1/8" plate between the skin and the ribs, the added mass may make it unlikely that I'll be able to line up the original rivet holes?. That could look messy.

Any words of wisdom'? Would it be best to end the plate short of the ribs?

I'm trying to anticipate the variables that could likely booger the rejoining exercise as this 30' 3 3/4" whale hovers above me in the wind. Thoughts are appreciated!

Cheers

Aerowood · 10-01-2021, 07:40 AM

What I did was to remake the plate from 2024-T6 .063 thick. I routed the bottom of the ply floor so the floor would set flush to the frame. My new hold down wraps under the floor and up the back of the of the C channel to rivet to the skin. I added another .040 Z that also is under the hold down plate and covers the rear cross member. Clear as mud uh. I posted some pics on my thread " 71 Globetrotter Full Monte"

Daytonacoupe · 10-02-2021, 07:10 AM

Quote:

Originally Posted by Aerowood

What I did was to remake the plate from 2024-T6 .063 thick. I routed the bottom of the ply floor so the floor would set flush to the frame. My new hold down wraps under the floor and up the back of the of the C channel to rivet to the skin. I added another .040 Z that also is under the hold down plate and covers the rear cross member. Clear as mud uh. I posted some pics on my thread " 71 Globetrotter Full Monte"

I had a look at your thread when deciding what to do. Nice work! I've gone back in and looked again. It appears that you didn't extend your plate beyond the rear vertical ribs. I think I'll shorten mine and affix it well to the rear panel between the ribs. There had been no plate on the trailer when I took it apart and no evidence of rear end separation so no need to be too aggressive with the plate. I'd like to avoid creating an ordeal where the interference results in the need for a new line of holes for the rear skin to rib attachment. Cheers.

Aerowood · 10-02-2021, 08:29 AM

The hold down plate extends to the outboard side of the vertical ribs. I then installed angle brackets to tie the ribs to the cross member.

Daytonacoupe · 10-02-2021, 09:35 AM

Quote:

Originally Posted by Aerowood

The hold down plate extends to the outboard side of the vertical ribs. I then installed angle brackets to tie the ribs to the cross member.

Thanks for correcting my wrong assumption. With >665 posts in your thread I must have been looking in the wrong pages.

Aerowood · 10-02-2021, 11:17 AM

Ok, I had to go out and look. It is indeed how I described. Couldn't get in and get a better pic, but in a day or two I will be removing a portion of my temporary bed frame for access to another area and will post a better pic. I will say that I did some creative shimming to make the exterior skin fair..

Daytonacoupe · 10-03-2021, 06:21 AM

Quote:

Originally Posted by Aerowood

Ok, I had to go out and look. It is indeed how I described. Couldn't get in and get a better pic, but in a day or two I will be removing a portion of my temporary bed frame for access to another area and will post a better pic. I will say that I did some creative shimming to make the exterior skin fair..

I appreciate the pic, thanks. I'm thinking that you avoided what I'm concerned with (lining up the old vertical rivet line holes to attach the plate, rib, rear, and side panel) by installing new aluminum panels. Shimming I can manage; it's the 'creative' part that challenges me!