Leaks and Floor Rot in '91 34' Limited

[Steve Bryant]

Perry,
This is a very deluxe answer with the solid depiction. I'd rate this as a Five Star Reply!!!

BTW, what sort of drawing/rendering program are you using. It's pretty cool!

Thanks,

Steve

[Becky B.]

It's much easier to find leaks if your interior is open. As long as you have your interior walls removed, it's very easy to remove the insulation & it's really not a big deal to replace it (I used Prodex in my trailer so the mice won't make nests in it!). All you do, once you have a bare wall, is take toilet paper & stick it to the wall in the area where you think the leak is coming from. Then spray with the hose (if you have a helper, they'll see pretty quickly where the water is coming in). Here's a picture of my interior. I had a leak next to the door & sealed what I thought was the leak....alas, it wasn't. It turned out to be a rivet at the very bottom of my toilet paper drapery!!Attachment 149204

I left the toilet paper up for a while to make sure it stayed dry through some rain & snow. It did--I just haven't had time to work on the trailer lately, so I'm officially leak-free. I've tracked down leaks in what is now my 3rd AS & they are truly a PITA!

[Steve Bryant]

Becky,
Thanks for expanding on your technique and providing the picture! I did a search on Prodex and it appears to be pretty interesting stuff. Also, I did a brief walk around inspection of the exterior of my trailer today (it's in the mid to upper 20s outside ... not a good day to work on the trailer) and I can see a number of things that need to have the caulking cleaned off and re-caulked. The awning support hinge attachments are very questionable as to whether they are water tight or not.

Pulling out the insulation will be fairly easy where I have the interior skin removed.

Thanks very much!

Steve

[perryg114]

It is called AutoDesk Inventor. It has made by the same folks that make AutoCAD. It is a 3D modeling program. I have gotten to the point where I hardly ever draw anything in 2D. The program makes all the projections for me. There are folks that use Google Sketch I think and it is free. I am trying to teach myself how to do CNC machining next. I will be able to make some custom parts for Airstreams or whatever. I have a motorcycle parts business right now and I design the parts and have them made locally. If I can make them myself I can save a ton of money and sell stuff more competitively.

Perry

Originally Posted by Steve Bryant

Perry,
This is a very deluxe answer with the solid depiction. I'd rate this as a Five Star Reply!!!

BTW, what sort of drawing/rendering program are you using. It's pretty cool!

Thanks,

Steve

[perryg114]

Whatever you insulate with make sure the water can get out from behind the insulation. You don't want water to get trapped between the skin and the insulation. I also don't like the foam in a can stuff. I have seen that stuff used on cars and every place it is used it causes the body to rust out. That stuff traps and holds water. You can use a combination of the Prodex and Rigid foam if you want as well. The Prodex stuff and similar radiation barriers work best if there is an air space on both sides of it. The stuff works by reflecting heat back where it came from. Lets say the Prodex reflects 90% of the heat energy that hits it. It heats up a little and the air acts like an insulator so that heat gained by the Prodex does not get to the other side. Now if something is touching it that heat is conducted directly to the other surface, the one you want to stay cold.

Perry

Originally Posted by Steve Bryant

Becky,
Thanks for expanding on your technique and providing the picture! I did a search on Prodex and it appears to be pretty interesting stuff. Also, I did a brief walk around inspection of the exterior of my trailer today (it's in the mid to upper 20s outside ... not a good day to work on the trailer) and I can see a number of things that need to have the caulking cleaned off and re-caulked. The awning support hinge attachments are very questionable as to whether they are water tight or not.

Pulling out the insulation will be fairly easy where I have the interior skin removed.

Thanks very much!

Steve

[Steve Bryant]

Originally Posted by perryg114

It is called AutoDesk Inventor. It has made by the same folks that make AutoCAD. It is a 3D modeling program.

Perry

It's a nice looking rendering. I have an older version of AutoSketch (another AutoDesk product). I've had three different versions of AutoSketch and the product has been discontinued. Instead, they sell AutoCAD LT which I suspect is a similar software application, but it's only 2D.

I also read your post #85 about Prodex. I want to consider Prodex, RMAX and other newer forms of insulation that are light weight and will not retain moisture. This leak/rot issue is an interesting challenge, but to paraphrase Becky, it is a pain in the postier that I had not anticipated.

Steve

[perryg114]

Steve welcome to the reality of owning an Airstream as opposed to the fantasy you were living prior to ownership. I also thought that an Airstream is aluminum so what is there to rot. I think I will remove more skin this weekend in search of new leaks.

Perry

[Steve Bryant]

Here’s another installment on my floor rot and leak investigation saga. I’ve worked a couple of days on the trailer since my last post (although more than a week has passed since that last post), done some research on insulation and purchased two sheets of Dow Super Tuff R (3/4” with an R value of 5). I got the only two sheets there were at my Lowe’s Store for $5.00 each. I’ve since found out that Home Depot has the 1” version (R 6.5) at about $18.00 per sheet. I got a great deal on the ¾ inch at Lowe’s because they were returned by another customer and my Lowe’s has stopped carrying the stuff.

As to the work in the trailer…I’ve removed the remaining right/curb side panel and all of the insulation that is exposed in the rear bedroom. I’ve also done a fair amount of cleaning with a shop vacuum and a stainless steel wire brush. Here are the basic photos of what has been revealed.

Curb/Right Side


Rear Wall


Road/Left Side

[Steve Bryant]

Now, for some details in my root cause investigation to date (I haven’t soaked it with water yet, just looked at the evidence):

Here’s one of the infamous gaps that Perry alluded to a few posts back (see http://www.airforums.com/forums/f36/...ml#post1095688 and http://www.airforums.com/forums/f36/...ml#post1095804 on the curb side. I’m going to call this the “gutter gap”.


Same gap on the road side.

[Steve Bryant]

Now for a couple of shots showing the corner damage from the rear end bumping something solid and bucking the lower porting of the rear corners. You can see the corresponding exterior shots on post 4 http://www.airforums.com/forums/f36/...ml#post1081408. I don’t know what happened when some previous owner had the trailer, but we all know stuff happens.

Right Rear Corner


Left Rear Corner (Note how much extra electrical cable is coiled up under the floor where it does no good.)

[Steve Bryant]

Here’s a trail of mold/mildew from a rivet that had been caulked but still obviously leaked…likely more than one is leaking.

[Steve Bryant]

Also worth pointing out here is that most of the drain/weep holes on the outboard side of the top portion of the C Channel/Gutter Extrusion are blocked, thus preventing the orderly flow of water.

Typical – Blocked Drain Holes – exterior skin (would be hidden beneath banana peel trim extrusion) was never drilled.


Exception to the Rule - Open Drain Holes
Note: the drain holes in both corners are drilled in the bottom corner of the gutter and thus may deposit any moisture onto the absorptive OSB that we all know and love! I’ll be investigating this further.

[Steve Bryant]

Current Overview




I’m putting on my engineer’s hat now. Here’s the way that I think these trailers should be designed and constructed:

• Minimize the leaks to some acceptable/quantifiable level by proper sealing
• Accept the fact that there will always be some minor leakage that will increase with the age, mileage, vibration levels, etc. that the trailer is subject to over its life.
• Provide a means of containing the minor leakage between the inner and outer skins by some sort of watertight spillway or gutter.
• Have a means of draining that spillway/gutter system overboard in a manner that will not harm interior components.

Initial Root Cause Analysis

• I believe that the design of the Airstream trailers is basically sound and the construction is good when viewed from a high level. However, the attention to details and the quality control could be a lot better.
• These trailers are probably sealed up pretty well when they pass the initial leak test. However, as many of us know, they do not fare well over the long run (or even the short run in some cases).
• The gutter system has some major breaches or voids (like at the intersection of the corner sections with the straight sections). This results in dumping any water flow onto the subfloor and carpet. Also, the fasteners (elevator bolts and hex head bolts) are likely not adequately sealed from the top (where they penetrate the bottom of the gutter.
• The drain/weep holes are either blocked or may dump water in a downward fashion onto the sub floor.

I’m interested to see what I will find when I do the water test and remove the remnants of the sub floor. On another note, I went to Home Depot today and looked at laminate plank flooring and I’m getting psyched-up about the prospect of having the floor all fixed from stem to stern. I didn’t want this problem, but it’s not as bad as it could have been. It does not appear that I have any separation in the back. Also, I’ve discovered that there are some significant internal doublers sandwiched between the sidewall skins and the frames. These doublers were likely an effort to reduce the problems with rear sag, in my opinion, and they probably contribute a lot to the stiffness of the structure. I’ll write more about this later.

Also, as an aside, I think that AS should have gotten away from spun fiberglass insulation as it really does retain the moisture.

[perryg114]

Those drains if that is what they are, are a new thing. They need to get water below the floor. It can still seep into the end grain of the wood unless that hole has some sort of protection to the wood in that area.

Perry

[HiHoAgRV]

IMHO, drains and such are not the solution...kinda like scuppers and bilge pumps added to a leaky boat...sooner or later the scupper will foul, the battery will die and the bilge pump will fail...down goes the boat...(from 1st hand experience...)...and in the interium, the entire leaky boat will smell like a musty mildewed mess

The best bet is to plan on fixing the leaks...I understand it HAS been successfully done by others...

[perryg114]

I am not sure that keeping a decades old Airstream trailer leak free is possible. Small leaks are normal. You should always strive for NO LEAKS but there needs to be a backup plan to prevent floor damage. Getting rid of the stinky pink stuff and removing accumulated water in the C-channel is a good thing. Condensation is enough in some climates to produce significant amounts of water to soak insulation and seep into floors. Just about all wooden boats leak to some degree. Rain will fill the bilge on a boat so not having a bilge pump is like not having a spare tire on a car. You know you are going to have a leak so get the water out before it can do damage. Are you really going to seal each and every rivet and seam from the inside and outside, because that is what it will take to get all the leaks.

Assuming you get all the leaks you really think it is going to stay that way?

By the way, I don't like the drain holes that AS put in this particular trailer. You need a pipe or something to get the water out while protecting the wood. A pipe that goes below the floor will do that. You can extend the pipe below the skins to prevent corrosion of the frame and belly skins.


Perry

[Steve Bryant]

Vernon and Perry,
Thanks for your input. I still intend to fix all the leaks that I can and change the insulation system. I plan to pursue a plan that includes all of the goals that I mentioned earlier:

• Minimize the leaks to some acceptable/quantifiable level by proper sealing
• Accept the fact that there will always be some minor leakage that will increase with the age, mileage, vibration levels, etc. that the trailer is subject to over its life.
• Provide a means of containing the minor leakage between the inner and outer skins by some sort of watertight spillway or gutter.
• Have a means of draining that spillway/gutter system overboard in a manner that will not harm interior components.

I'm planning to bridge the gaps like Perry drew so nicely (maybe even including the drain tube). For now, my plan is to incorporate the belt (minimize leaks) and suspender (contain water runoff in a drainage canal and give it an exit path). I'll probably employ solid foam insulation under the floor too.

Keep the cards, letters, ideas and feedback comin'. This boy needs all the help he can get!

Steve

[Steve Bryant]

I sawed two kerf’s with my circular saw that were 1/2'” deep so as to not get into the frame metal. The positions of these kerfs are in approximately the same position as what I’m planning for the replacement segments of plywood (24 inches inboard from the outside skins).


Then, after sawing these shallow kerfs with the circular saw (AKA “Skil Saw”), I finished up the cuts with my oscillating multi-tool, taking care to control the depth over the steel cross members, outriggers, etc. After removing the OSB, spun fiberglass insulation and cleaning up with a putty knife, shop vacuum, here’s what I found. Things are in pretty good shape underneath.

[Steve Bryant]

My friend, Ralph, came over this afternoon and helped with some of the housekeeping described in the last post and then we conducted a water test two times from the bottom up, marking leak locations with a permanent marker on the inside. I want to make an initial pass at fixing these leaks and then I’ll re-run the water test and do a second wave of sealing before I tear out the remainder of the floor in the C channel, remove the bolts, banana wraps and floor pan to prep and paint the frame with POR 15.

Below, you can see a sample of some of the pictures of leaks and body work that needs to be done. If you want to see more pictures, go over to the album where these photos are hosted and peruse them.

[Steve Bryant]

This is one of two walking (weight distribution) boards that I made when I worked on the roof to replace the Kool-O-Matic with the Fantastic Fan Vent and other work on the top. On the top, I put the carpet side down and ran the boards aligned lengthwise with the trailer. On the inside, I’ll have the carpet side up.