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Isaiah · 08-04-2017, 01:42 PM

We just purchased a 69 tradewind and the rear plywood is very rotten. Leaks around the tail lights it appears. I should have gotten on this forum and read about airstreams before I got one, but now I'm stuck. When I run my fingers along the bottom edge of the rear hatch, then area between the U-channel and the frame is essential void of plywood. And I can feel some spots where the bolt heads have either deformed the u-channel or are just rusted off, and it other places they appear to feel intact. The bumper does move a bit relative to the shell when I bumper jump, but I don't really see much evidence of frame sag, the cavity where the plywood rotted out appears to still only be around 5/8-3/4" between the u-channel and frame. Which seems to suggest there is not much separation. The angle iron at the bumper where the plywood rested is rusty but seems sturdy.

So before I undertake a fix, I just want to make sure I've got the process correct, and actually understand the construction of this thing. Seems like what I need to do is pull everything out of the bathroom to expose the floor. Cut out the floor from the rear support back over the back water tank. I can take advantage of the fact that there is a little extra room between the U-channel and frame to get a sheet of plywood back in where the original was. Notching the plywood to slide in around the bolts that are still good, and cutting out the bolts that are broken. Then peel back the inside skin of the camper on either side of the rear hatch to expose the U channel. Jack the bumper up until everything is sandwiched nice a tight. Put some new holes and bolts down through the U-channel, through plywood, and through the angle iron. Maybe add a strip of steel to the top of the U-channel to reinforce it in case root ever becomes an issue again. Drop the jack and close up the skin.

Does it seem like I have a clear understanding of what is going on in there? And is the approach sound? I'm having trouble finding an RV place local that will work on this thing, and even if they would I'm not sure I'd want them to. For those who have done this before, is this a long weekend type of job, or am I looking at some considerable labor hours? Thanks in advance for the help!

Boxite · 08-04-2017, 03:23 PM

While I have no experience with this particular repair.... I do have experience with similar jobs and old equipment... and it tells me that when you get into this job... you're going to find that "while I'm in here I might as well go ahead and...."

It sounds like this is going to be more than just a weekend. And you're right... you want to do this yourself unless you have a fat wallet and lots of patience with people who don't care about it as much as you do....

But CONGRATULATIONS on becoming an Airstream Owner! You'll some day be really proud of it!

AlinCal · 08-04-2017, 03:34 PM

I have not been were your about to go but...Logic tells me when you get everything out and the old floor up you will see the frame and it's going to dictate whether you need to address it or not, sounds like it's still solid.
Good luck!

HiJoeSilver · 08-04-2017, 05:32 PM

It's more than a weekend for sure. Plan on a few at least. You've got the basics down pretty well though.
When you put it back together slip some aluminum in just inside the back skin protruding down to block water.

Post #8 in this thread has some pictures to give you an idea on the flashing.
http://www.airforums.com/forums/f477...ml#post1988045

The steel plate backers you mention can be done but instead of steel use some 1/8" aluminum, it won't rust away. It's acting as a big washer, it's more than strong enough.

You should find 2 larger bolts (5/16) that go through the u chanel and bolt through the frame rails. They typically have steel plate backers. They can use aluminum. The rest of the bolts should be 1/4". If you spray the bolts with galvanizing paint after install it helps stop them from rusting.

You can reuse the holes in the u chanel to guide holes to drill through the new wood.

Paint or epoxy the wood especially edges to prevent future rot.

You'll need to remove the banana and belly wraps in the back so you can get to the bolts to tighten them down. Can't think of any other way. Replace all the ones you can get to.

Jamespio · 08-05-2017, 07:07 AM

I think you've got the right general idea. Having done a poor job of this particular repair once, I would tell you to be more aggressive. If you're going to remove the bath, you're getting into a multi-weekend job. Which means, IMO, you should not try to notch around the bolts that are still sound, just replace everything. Any bolt that has been holding together an aluminum/plywood/steel sandwich for nearly 50 years, deserves to be retired.

Inserting the plywood is going to be really difficult. I think I made 38 attempts to install the new plywood (and I was taking a major shortcut that I don't care to talk about in mixed company), making additional cuts between every one of those attempts. This is because I was trying to disturb the existing plumbing and electrical as little as possible. It's like putting together a 3D puzzle inside an opaque envelope where all the pieces are close, but don't quite fit. It will be easier if you totally gut the rear service center and all of the plumbing, but then you'll have to rebuild the whole rear service center and all th eplumbing.

In short, plan adequate time for this job, much more than you think it will take.

Madmarke007 · 08-05-2017, 11:31 AM

My 70 Tradewind took more than a few weekends. While bath is out is time to add grey tank. It was easier to cut tub in two vs taking sink out. Replaced with shower pan for easier shower access.

jimstream · 08-05-2017, 02:31 PM

I had rear end separation on my 1968 Safari 22 many years ago. I took it to Jackson center and they repaired it by going in from the outside. They had to cut the rear quarter panels from the top of the rear "trunk" door in a graceful curve down to the c channel. They were then able to cut out the rotted floor and remove the rusted cross member and replace them without disturbing the bathroom at all. They did a very professional job of replacing the pieces cut out of the rear quarter panels so they look like they were part of the original construction. They are referred to as "elephant " ears. Big advantage is you don't disturb the bathroom which is a major, major job to reinstall. It did not seem too expensive to me then, but I was still working. Check for current rates. They were doing them regularly then and had the system down so may not be too expensive. Good luck!

TxDave · 08-05-2017, 04:25 PM

You seem to have a good understanding of the process. We did pretty much exactly the same on our 1971 Sovereign. Replaced the last 4 feet of subfloor in the bathroom area. We also dropped the belly pan in that area and replaced the black water tank and insulation.

Tbeck11931 · 08-05-2017, 04:52 PM

I'm in the middle of a shell off repair on my 1991 after attempting a similar repair. Problem I found during my repair is the frame damage. Good luck

ke6gkv · 08-05-2017, 10:07 PM

You have a sound plan. I did something similar.i cut the rotted floor from wall to wall in front of black tank.cleaned out c channel,sanded few rust spots on frame, slid new marine-grade plywood in.sealed and buttoned up. Kurt

SuzyHomemakr · 08-06-2017, 02:36 PM

In addition to what all those guys said...

If you are fortunate, there will be nothing but slight surface corrosion on the frame members. Coat everything that you can reach with POR-15, truly amazing stuff. That should stop any corrosion in its tracks. Don't forget to seal the edges of the plywood- I would use a penetrating sealer like Thompson's. I'm not a big fan of coatings that sit on the surface in this case, as the vibration and lack of drainage can eventually break the coating free of the surface. Then it won't drain or dry out, for sure!

Good luck with the bathroom removal. That plastic gets brittle with age. When I did my rear floor, I knew ahead of time that I was throwing the bathroom away, so I didn't really care about the condition of the junk coming out. It did snap rather easily, as I remember. Smelled bad, too.

As for the plywood, this is the time to step up to the plate and get the good stuff. You want at least marine grade, with no voids. Some guys go as far as using Lloyd's rated okumne, which is breath-takingly expensive, but that's kinda overkill, in my opinion. I've been using Eurolite ply in various thicknesses throughout my build, and other than a throbbing wallet, have found it to be a superior product. And 40% lighter than regular ply!

Otherwise, you seem to have a good grasp of the task!

Isaiah · 08-06-2017, 04:31 PM

Thanks so much for the help everyone. I'm keeping my fingers crossed for no frame damage. But at least my brother in law is a welder!

ventport · 08-06-2017, 04:57 PM

When I did my 77 Argosy I welded extra floor braces left to right and front to back to re enforce the floor where you walk. The factory put very little support in this area when built. Before I started welding in the braces I jacked up the bumper to remove any sag before welding. Been 8 years with no problems and the floor is solid as a rock.

Isaiah · 08-07-2017, 10:23 AM

Ok, so one thing I was picturing wrong. I guess I had assumed (for some reason) than the channel fastened to the frame continuously along the outer edge. Not sure why I thought that. Obviously doesn't make any sense. But in the bath the elevator bolts are only attaching the shell directly to the frame at the rear angle iron correct? In every other position you are only attaching the to the plywood, which is attaching to the frame elsewhere. So that's really the critical junction, because that is the only frame/shell "sandwich". So I really need to reinforce that angle iron and the U-Channel with aluminum on both sides and seal the plywood with epoxy (or similar) because that's really where I'm going to get bitten later, if anywhere.

65will · 08-07-2017, 11:27 AM

I have a 69 Trade Wind that had the same issue. The water comes in from the piece of aluminum that runs from your bumper under the shell. I had to remove the entire bathroom and floor. Then I found the pan that holds the black tank had rot along with the brackets that hold it in the frame. Found a soft spot in the frame. Found the c channel that you bolt the shell to bad. I removed my plywood to where the 4 foot sheet seamed, which is at the bathroom door. When you go to put the plywood back in get some help have someone stand on the bumper it opens a gap and allows the plywood to slide in. This is a big job but very doable. we love our Trade Wind.

Glenritas · 08-08-2017, 09:50 AM

On my '69 Tradewind I found water damage to the rear floor caused by several things.

1. Was caused by the p.o. who hit the banana wrap then took it off and put it back on with screws on the outside of the upper panel. Over time it came loose and collected water which destroyed the floor in the left corner.

Glenritas · 08-08-2017, 10:06 AM

2. Was caused by a design flaw of the rear compartment sheet aluminum on top of the frame rails that slips under the plywood with no water barrier .

Glenritas · 08-08-2017, 10:19 AM

3 Was caused by no seal on the propane line coming up into the water heater.

4. Was caused by a leak at the tail light bucket .

Glenritas · 08-08-2017, 10:29 AM

The end result was to replace the last 4 feet of the floor and come up with a seal for the design flaw.

Glenritas · 08-08-2017, 10:49 AM

Opps ... a bit out of order on the floor repair.

The last 2 are of the new L flashing that is tucked under the molding and sealed to the body and has a Butal seal to the top plate to seal out water to the plywood.

To install the plywood, I welded an angle iron front to rear between the frame cross members. I split the plywood into two pieces (left & right) and slipped them into place and screwed them down to the frame and the body to them in the c channel . Of course I bolted the rear center section to the frame.