how to check for frame rot ?

[oldvws]

Wonder what the signs of frame rot are ? or as said below "Chassis " rot, Rust , cracking etc

Since it has a bellypan, how do you see the frame?

I understand if one side is "listing" to one side

But are there any other ways ?

And where does it rot the most ?

I would assume under the sink or toilet area but anywhere else that needs inspecting ?

Again thanks for your advise......again

[smallfry]

OK - first, I know nothing. To prove it, I just bought a really OLD AS Bubbles model and trust me, I've seen rot. Where? The obvious places you've noted: toliet area, sink area, etc. Entry way of course. The worse place to get it from what I've read, is around the perimeter - where the floor fits into the channel at the base of the sides. Look there first. It's sort of how if you drop a piece of bread - it'll probably land on the buttered side. I don't know why.

[53flyingcloud]

oldvws
If by "frame rot" you're referring to the chassis frame, then I assume you mean the steel frame that the whole unit is attached to..Correct??
The only thing that I can share with you on this is what I saw this past July. While I was at the service center, I saw a unit from FL that had the front section of it's frame exposed (belly skin peeled back)just under the window(A frame area).It was almost rusted thru completely~!
The factory re-enforced that area by welding a new section to it..Whew..talk abt something to keep an eye out for...
hope this helps...
ciao

[NewStreamer]

good question,
take a peek at a complete frame replacement , and why it needed to be replaced, in the picture section. (posted by thomas in Germany)

I hope someone will tell us where to look, and how to look for rust without peeling off the underskin.

Ron

[nickcrowhurst]

I saw some Airstreams in a wrecker's yard that were only ten or so years old, and had severe structural corrosion of the frame. This was visible where the trailers had ruptured in the wreck. Particularly bad was the rear few feet. My trailer is a 1988 Excella, and by looking in the rear fender locker I could see through a 2 inch diameter access hole in the rear frame members that there was serious internal corrosion, with thick flakes of corroded metal ready to lift off. The rear fender is secured by four zinc plated machine screws, rusted into place. I drilled these out, removed the rear fender, and was able to inspect the last section of the frame. The corrosion was bad enough that it had to be stopped, but not sufficiently advanced to require welding. I bought a car body rustproofing kit from J C Whitney, connected the sprayer via a 25 foot long hose, and using a compressor, and with the hose inserted right inside the frame, I attempted to spray the whole inside of the frame. Unfortunately, my compressor was not powerful enough to cope, so I jacked up the rear of the trailer, and poured a few pints down each tube, left it overnight, and then returned it to level. This is better than nothing, as the liquid will at least treat the areas where water might collect. I redrilled and tapped the four machine screw holes, and fitted stainless steel replacements.I plan to find a professional rust proofing company to whom I can deliver the trailer with the rear fender removed. One place for electrolytic corrosion is where the front A-frame (steel) enters the front body (aluminum). There should be some rubber or plastic strips to electrically separate this point, which is prone to be soaked with salt spray. If there is metal to metal contact, you will see corrosion at the junction. Apart from stripping off the underbelly, that's the best I can suggest. Good luck. Nick.

[John]

I'm going to be camping for at least one month about a 1/4 of a mile from the ocean waters, with only sand dunes between.

Besides regular washing(once a week), are there any other suggestions out there to help prevent build up of salt on the frame?

I was thinking of spraying used motor oil to coat the frame prior to heading out. A buddy of mine who lives next to the beach down here, has does this to his 73 chevy for years and has zero frame rust. Or am I being to zealous?

John

[hex]

Don't use used motor oil. It is just too nasty and after collecting dirt and road grime you will be oh so sorry you did it. If motor oil must be used buy some new. a quart should be enough to cover it all twice or more.

I would think the under belly will offer protection during your short stay. Surely you dont plan to drive in the surf or park there. Maybe you could spray the tounge and rear bumper with WD-40 each week you are there.

Re: frames with existing scale and deep pitted rust.
I would think twice about applying a setting-up type of undercoating on the frame without removing or neutralizing the scale first. If the scale can not be gotten to for removal, then I would recomend a thin oil spray application 2 or 3 times per year in the interim. Ingenuity will figure a way to get the oil in, but it is gonna make a mess in the "basement" for sure. Some will certainly leak out in your driveway for months to come.

[nickcrowhurst]

Airstreams seem to die from hidden corrosion of the frame. I helped a friend to dismantle the back end of a Sovereign 25 rear bath. The rear crossmember just did not exist. In the belly pan was a bucket-load of rust flakes. Another friend has had to take his 34 footer to the salvage yard because of extensive frame rot.The only way to check external corrosion of the frame seems to be removal of the belly pan, but this is not a simple process, and would involve considerable dismantling of other parts, factory fitted, with consequent risk of leaks or damage on re-assembly. The sheets of the belly pan appear to be cold-crimped together. The interior of the box section is another problematic issue.
In an attempt to slow down the corrosion on my trailer I have purchased a fiber-optic device, similar to an endoscope. It is a Pro-Vision 18" Flexible Fiberscope, costing $211 (inc S &H) from www.qualitywholesaletools.com tel. 515 961 0566. I've also purchased (again) the rust-proofing kit and fluid from J C Whitney at http://www.jcwhitney.com/autoparts/B...001264/c-10101

Two AA batteries are required to power the internal light. I used the fiberscope yesterday for the first time. I am very impressed with the instrument. I can see that the main frame corrosion is hidden INSIDE the box sections. There is heavy pitting, but, thankfully, little flaking. I am now more determined than ever to get a more powerful compressor and spray all the inner surfaces. I can see that my previous effort coated the bottom third of the box section. I shall drill 1/2" holes all over the bottom pan and bananna wraps, and use these for frame inspection with the fiberscope, then for spraying fluid, and then for final inspection to check for coverage. Plastic plugs will then close off the holes. One challenge will be coping with the fiberglass mat insulation in each cavity. I'm leaving for home in the UK now, so will do the full job in November when we return.
Once an Airstream is water-leak free, I regard this as the most important issue for preserving the trailer. Unfortunately, it is one of the most difficult.
Nick.

The English use a product called Waxoyl, to rust proof the frame and body cavities of their cars. It's available here in the U.S. in kits with spray wand etc. I used it in the box section frame of my Land Rover. It creeps into the nooks and crannies and stays somewhat soft and flexable. With some spray on undercoatings, they dry out , crack and then water has a chance to get behind them and do damage. Do a Google search... the stuff really works well.

[Torii]

Nick

I was looking around and came across this site which not only has the same scope you bought but also some longer versions.



How flexible is the fiber optic 'neck' on the one you bought? Can you "shape" it and have it hold or is it more akin to a piece of coax cable?

-T

[nickcrowhurst]

Originally Posted by T Man

How flexible is the fiber optic 'neck' on the one you bought? Can you "shape" it and have it hold or is it more akin to a piece of coax cable?-T

T, the cable stays in whatever shape you bend it. They recommend a minimum radius of curvature of 8" for repeated bendings, and to use curves rather than sharp corners. It's interesting just how many uses I've found for it in the first 2 days. I used it to check the indicator lights on the surge supressor on the 120 v outlet for the refrigerator. This is in a very awkward place. I also used it to locate a pipe clip on a fuel line behind the fuel pump on my Cummins engine. This is absolutely impossible to see without some instrument. It's a lot of money for the instrument, but I've thrown $200 at many other jobs on the Airstream, and none were as important as this.
Nick.

[nickcrowhurst]

Originally Posted by Craftsman

The English use a product called Waxoyl, to rust proof

Craftsman, I'm English, and yes, I use Waxoyl on my Land Rover in England. I've tried the hand powered pump that the company sells, and ended up with a gallon of Waxoyl all over the driveway! I now get my local garage to spray it with a powerful compressor every few years. It comes as clear or black. I prefer the black as it's easier to see where the spray has been. BTW, I'll be with my son next week at White Hall, MD, just 18 miles from you. You're welcome to borrow the fiberscope for a week if you want to play with it.
Nick.

[Holzarbeiter]

POR 15 is a great rust converter and has been used in the auto restoration industry for years, remove the heavy scales and brush on wait 5 hours recoat, comes in clear,black and silver, not a cheap product but than again what is your coach worth to you?

[nickcrowhurst]

After inspection of various sections of the frame with the fiberscope, I decided to create an inspection hatch for each sub-compartment inside the belly pan. That's about 20 hatches. In the center of each compartment I cut a rectangular hole about 6" along the longer axis of the compartment, and about 5" on the other axis. The holes are only visible from underneath the trailer. I started each hole by using a 1/2 inch diameter flat wood drill bit very gently at each corner, and joining the holes with my Goscut snips.I then put my hand (wearing leather gloves and a long-sleeved shirt) into the hole, and removed and discarded the pink fiberglass insulation that partially filled each compartment. Using a small flashlight, and occasionally the fiberscope, I could see that the main corrosion was where the aluminum belly pan was secured to the frame, and where the insulation had been trapped between the OSB floor and the frame. In one compartment, under the range, there was no insulation. The frame in this section was as new, with shiney black paint all over it. The creation of rust requires some moisture, and I suspect that the source of this is interstitial condensation. For those that are familiar with this phenomenon, please ignore the next section.
Human beings create a warm moist atmosphere when they live and breath in a house or trailer. This creates a higher "vapor pressure" in the trailer than inside the cooler, dryer, belly pan, for example, on a cool day. This higher internal vapor pressure forces the warm moist vapor through the porous floor and any openings in it round pipes and wires. If there is insulation under the floor, and no vapor barrier, the air temperature in the insulation will drop rapidly through the thickness of the insulation, getting colder as one measures further down towards the ground. If , at any point, that temperature drops to that day's dew point, condensation will form in the insulation and in the compartment, leading to rot and corrosion. To prevent this condensation, a complete vapor barrier is required on the hot side of any insulation. That is why houses are wrapped in vapor barrier before the insulation is added. It is also why the vapor barrier must be preserved intact when remodelling, re-plumbing or re-wiring.
I suspect that the external frame corrosion I am seeing is caused by this interstitial condensation. I have therefore decided to discard all the insulation from inside the belly pan. The interior of the belly pan will stay warm. There will be some loss of heat because of this, but I consider this to be the less of the two evils. I will add another layer of carpet if required for comfort.
After cleaning out each compartment I will spray the frame with the rust-proofing fluid from JC Whitney, and seal each hole with a hatch made from scrap aluminum, secured by eight 1/2 inch by 8 stainless self-tapping screws.
Nick

[nickcrowhurst]

I've been trying to devise a system to spray corrosion prevention fluid inside the long frame box sections. I contacted the company that supplies the spray gun and fluid to JC Whitney. The company is Tri-Con, LLC 27331 Tungsten Road, Euclid, OH 44132, tel. 216 261 3400. I spoke to the owner, Mr John O'Brien, who was extremely helpful. He said that the model 9000 siphon gun supplied via JC Whitney is ideal for the thicker fluid for the outside of the frame, but that the inner cavities require a fine mist of a thinner fluid, supplied via an air pressure gun. He is supplying me with the Tri-Con model 1800 pressure sprayer, with a 24 foot long 3/8ths of an inch diameter (approx.) steel tube to slide into the long box sections. I chose the length to fit my trailer. The tube will comprise six 4 foot lengths which screw together. This was at my request, for ease of handling and transport. At the end of the tube will be the company's 360 degree misting attachment. I guess the total cost will be about $180. The company has previously supplied this set-up for spraying inside aircraft wings. The company' s website page for the 1800 sprayer is at http://www.triconsprayers.com/viscous.html
For the fluid, as recommended by Mr O'Brien, I went to www.eastwood.com, and ordered 2 quarts of Heavy Duty Anti Rust, part# 16017ZP, for a total of $37 inclusive.
I will need to make a spacer, perhaps a wooden block, taped to the misting attachment, so that the attachment rests on it, and sits centrally in the box section. I will be using a 1 H.P compressor.
The job will have to wait until November, when I am next back in the USA with the trailer.
Nick.

Nick, thanks for the offer of the fibrescope. I worked for Land Rover North America for a number of years, and got some training at the factory in the U.K. I think one of the reasons that I'm so attracted to Airstreams is because like Land Rovers, they're aluminum and held together with rivets. When it comes to the frame, because they are insulated and sealed with the belly pan, they should be treated in some way from the manufacturer. I for one would like to see them galvanized. Then the frames would last as long as the body. That was the one weakness with LandRovers, the frame would rot out long before the body. Sorry about the bad scan.

[nickcrowhurst]

I'm getting ready for the end of November, when I aim to return to my trailer and carry out the spraying of rust prevention fluid both inside and outside the frame box sections as described earlier in this thread. The thinner fluid for the inside of the box sections requires 80 psi at 4.5 cfm, so I've ordered an 8 gallon 120 psi, 5.6 cfm 120 volt compressor from Harbor Freight for $100, part # 90385. I need to slide 24 feet of thin (quarter inch diameter) steel tube down the main frame rails. At the end of the tube, the spray nozzle is the same diameter. I wish to keep the nozzle in the center of the box section to provide an even spray pattern, rather than let it rub along the rusty bottom. My initial thought is to tape the end of the tube to a smooth block of wood with rounded corners to prevent snagging. If anything was to jam, I would aim that the tube pulled away from the tube and the wooden block as a failsafe.
Could a kind forum member please post the inside dimensions of the main frame members on a late eighties Airstream, so that I can fashion a gadget?
Also, has anyone any better ideas for keeping the nozzle centralized? Perhaps two Meccano wheels on an axle with the tube resting on the axle and taped to it? Thanks.
Nick.

[eddieboy]

All this talk about the interior rusting is getting me nervous about buying an older Airstream. YIKES! I was thinking to buy a 70's or early 80's model.

[nickcrowhurst]

Eddieboy, welcome to the forum. Your nervousness is well justified. My trailer's frame is in comparatively good condition solely because I was lucky. I had no knowledge of Airstreams when I bought it. You are in a much stronger position to make a sensible choice now you have started to explore this forum. A few hours using the search facility at the top of the screen will pay dividends.
Nick.

[Gerlach Dave]

"I wish to keep the nozzle in the center of the box section to provide an even spray pattern, rather than let it rub along the rusty bottom. "


Wire ties, just use 4 wire ties set 90 degrees to each other, cut them to fit the shape and shove away. You can wrap them with tape to keep them lined up. The nylon will keep things centered and be flexible enough to not get stuck.