Leaks and Floor Rot in '91 34' Limited

[HiHoAgRV]

Steve,
here's a link to my frame-off '63 thread where I painted the frame/epoxy'd the flooring. I used a twisted wire cup/angle grinder to knock off the rust.

http://www.airforums.com/forums/f109...tml#post966651

On Edit...I have used the metal prep, but only when the surface was sand blasted.

[perryg114]

I put POR15 on mine with very little prep other than removing as much dirt from dirt dobber nests as I could. It will bond dirt, rust, and whatever very effectively. You do want to get any oil off. The prime source of this would be from penetrating oil used for getting bolts loose. It also WON'T come off your skin. No solvent will touch the stuff once it has dried. You want to make sure the metal is dry otherwise the stuff will cure before it bonds properly. I filled my frame beams with this stuff to kill any rust on the inside. I put tape over any holes and tilted the trailer down hill and little and poured the stuff in there. Then I tilted it back the other way a little. You want to make sure you don't stick a brush in the can because you could cause the whole can to harden before you finish. I would get as many loose chunks off as you can but don't try to get it down to bare metal. This stuff likes to bond to rust.

Perry

[Steve Bryant]

HiHo and Perry, thanks for your input. I have a twisted wire cup for my Makita grinder and it works great. However, I think that ideally, the POR-15 wants a little iron oxide to cling to, so I may or may not use the cup. I'll probably call the POR folks and ask their advice. I also think that I'll look into the Raka Epoxy. HiHo, I'm rethinking my splice concept based on your suggestion of using a doubler (screwed & glued - could use Titebond II). I can't do this everywhere, but I could use it mostly.

Thanks,

Steve

[Wabbiteer]

Belly pans off. Sure you don't want to hear it but take them off. If you paint with POR you will miss coating the entire lower iron edges w/ 3 coats where it makes the nice battery-like reactions with the aluminum sheets and rivets, err.. that is except for the paint runs that weld the sheets in place yet leave nice water holding pockets. Yes, literally weld with POR - the layers of aluminum and iron oxide with POR soaked in turn concrete welded in place - snapped / buckled my rear C-channel lifting shell from about 15-inches of paint run between shell sheet and C-channel.

[perryg114]

Yes remove everything you can. The frame rust is going to be bad along the bottom edges. You can use POR 15 on aluminum it won't hurt anything but surface prep maybe reguired to get the best bond. I coated that Steel L-bracket at the back with the stuff and all the surrounding Aluminum.

I used polyurathane to coat the new floor. Epoxie may have been better but I was running out of time. I have coated several things with poly and it works well but it does not like being in the sun. Coat all edges and top and bottom and preferably any screw holes you make in the wood. I have some work benches I have covered with the stuff and it holds up well.

Perry

[Steve Bryant]

Wabbiter and Perry,
Thanks for your input. I called POR-15 today and he highly recommended that I brush (by hand or electric) and use Marine Clean and then the Metal Prep (thoroughly rinsing after each step and allowing to dry thoroughly) then two coats of POR-15. I bought all the materials from Vintage Trailer Supply (great folks BTW, excellent customer service) so I don't plan to skip any steps including removal of the belly pan. The main problem that I see now is that Matt recommended that the temperature be at least 50 degrees Fahrenheit to do the painting. I'll really have to pick and choose my day or wait until spring, which I don't want to do. I've removed my Suburban furnace and I have an abundance of mud dauber residue.

[perryg114]

You could do the tops of the frame rails and cross members now if you want to get the floor back in and then in the spring you could do the rest of the frame from underneath. My belly is exposed in mine right now but the wood is sealed and I have silver duct tape around the belly band area to keep water out. No leaks in that area after patching the roof vents.

Perry

[Steve Bryant]

Perry, I like your idea a lot!!!

[Wabbiteer]

Remember -Cured POR-15 will need to be sanded to get even POR-15 to stick correctly - or some of their $pendy tie-coat primer etc.

I think they are warning you against cold painting it since it really may not key in or penetrate as well as it would warmer.

I've painted POR-15 outdoors at night, by the light of a 13w fluorescent drop-lamp, with temperatures going below 40°F long before I finished. Winds were up too, 10-20mph swirling around too. It was dampish and overnight dipped to 35°F or lower and it cured okay, when I redid it just a month ago many places rejected scratches from an angle grinder grinding wheel until I'd really laid into it for a while so I can vouch it hardens okay, just maybe not keys into the pores as advertised or something..

I had thinned the paint with their thinner to stretch it some and thinned it again once it was starting to turn into melted ice-cream texture from trying to harden up. Its real thin to begin with so its not really needed.

[perryg114]

I think the reason for 2 coats is to make sure you get all the holes and defects in the coating sealed. I coated over the cured glossy black with more glossy black and it seems to be adhearing well. It is really hard to screw up POR15. They have a version to coat gas tanks so you know this stuff is tough. Getting rid of the fiberglass is going to reduce frame rot by a lot no matter what you put on the metal.

Perry

[wasagachris]

uh nobody is mentioning it but how do you intend to tighten up the elevator bolts holding the floor to the frame unless you open up the belly pan. Unless you have access to below the floor how can you put a wrench or ratchet to the nuts for the elevator bolts. I'm just saying.

[perryg114]

The newer Airstreams have a box beam so the only way to put bolts in them is to screw them in from the top. ALL of my elevator bolts were phillips head and the frame and cross members were threaded for 1/4-20 screws. I did not find any phillips heads like the factory but I did find slot head elevator bolts at Mcmaster.com. I had to drill and tap new holes in many areas. Some of the old bolts were broken off in the frame due to rust so I ground them flat with an angle grinder. I also welded in some extra supports so that all edges of my 3 piece rear floor were supported.

I think he should remove the belly skins before replaceing the floor but he does not have to completely redo the frame right now. Messy time consuming stuff can be left till spring.

Perry

[wasagachris]

Perry you're mixing up floor screws with elevator bolts. Elevator bolts have a flat faced head like a carriage bolt and they are used through the C channel and floor into the outriggers. You should also have two main much larger bolts in the rear section of the C channel into the main frame rails. I'm not exactly sure about 80's units but my 70's did have two bolts at the rear and two more at the front.
It has been advised by professionals to add both front & rear holddown plates to 80's units. Airstream eliminated these plates some time in the 80's and it has led to serious problems with the shell cracking at the entry door frame because too much stress is transfered to the shell with out these plates. The plates are welded to the frame rails and are riveted to the shell with two rows of rivets running horizontally across the front of the shell and with one row of rivets across the back. It has even been suggested to add more rows of rivets to existing plates to further spread out the stress load.

[Steve Bryant]

Perry and wasagachris,
I'm thinking of removing the exterior trim over the banana wrap/C Channel intersection, the banana wraps and the bumper sill if I have good weather for a few consecutive days but not the flat belly skin itself when I prep the tops and possibly the sides of any rusted frame, outrigger and cross-member areas. Then, I can slip the banana skins back on if necessary to do the painting at a reasonable temperature. I won't rivet them back, I'll just temporarily seal it up with some type of waterproof tape.

Then I can cut and apply epoxy to the plywood sub-floor sections (all sides/edges) and stick them in place. Then on another couple of good weather days, I'll pull the banana skins off to prep and paint the bottoms of the frame members and put nuts, washers, etc. through the C channels where they meet steel members. I can stick the banana wraps back on temporarily if weather requires or leave it off and pull the belly skins too for an inspection.

I don't know how I'll manage the logistics, but I like Perry's basic idea of doing this thing in segments that are workable even in winter. For example, it was 20 degrees F this morning and we've had rain/sleet for two of the past five days. But, I want to keep working on this and not wait until spring.

[perryg114]

On my tail and probably his there are three types of bolts. Elevator bolts for holding the floor to the frame, outriggers, and cross members. These don't have nuts on the back side like in the older models. They are threaded directly into the metal underneath. There are 1/4-40 bolts with nuts that hold the corner edges of the C-channel to the floor and more of these at the back between the frame rails. That go through the C-channel, floor, and then the steel L-bracket and then into the frame cross member at the very back. There are two larger bolts 5/16-18 with nuts at the back of the frame on each side that are on either side of the steel L-bracket. I don't think it matters what sort of bolts you use on the corners as long as you have plenty of washers and lock nuts or nylock nuts. I made some load distrubution plates to reduce point loads on the C-channel at the back. I will send some anotated photos later.

Perry

[perryg114]

Ok here is how mine is laid out. For some reason the cross member at the back of mine was about 1" too far forward so the put the bolts right at the edge of the C-channel and even notched the C-channel to make room for the bolts. I made a load distribution bar to even out the load on the C-channel. I had to weld tabs to the bar in some cases so the bolts would have something to grab onto. I did something similar in the corners. The is very little support in that area. A thin piece C-channel is all that is transfering the load to the main frame members. Had this been a rear bath I think the rear end would have separated from the bolts pulling out of the C-channel.

Here are the bolts I used without the nuts. You can use nuts in some places but being able to do everything from the top had its advantages. I think I put the floor down then drilled the pilot hole for the tap. Then I tapped them and spot faced the hole with a wood cutting spade bit to countersink the elevator bolt. It is not a bad idea to remove the floor and seal the holes with poly or whatever.

http://www.mcmaster.com/param/asp/PS...MainWidth=1597

[Steve Bryant]

Perry, I think that your trailer construction is pretty similar to my '91. Once I get back to working on it, I'll take more pictures. I appreciate the time that you've taken to submit and add the labels to your picture.

I'm still working on my NT-35K Suburban Furnace ... (today repainted the cabinet inside and out today and some portions of the heat exchanger with 1200° F exhaust manifold/header paint). I've made some replacement gaskets, etc., too, as most parts for this furnace have not been readily available for several years.

[perryg114]

Make sure you fire that thing up outside the trailer for the first time. There will be a lot of volitiles coming off that paint till all the binders cook off.

Perry

[weggie]

Originally Posted by Steve Bryant

OK, this is a test. I have an account at PhotoBucket too and I would like for you good folks to test this picture and see if it causes any trouble in the way of a fake virus program or anything like that.

Then, please let me know your results. If the results are good, I'll work with Aage to get the previous post links fixed.

Steve

I had no trouble viewing the picture.

[Steve Bryant]

For anyone who is interested, here's the link to my Suburban NT-35K Cleaning and Refurbishing Thread http://www.airforums.com/forums/f427...ace-86137.html. Now, soon I'll get back to the floor and leak issues.

Steve