Difference or changes in the '60s to the '70s frame?

[purman]

Seems like a lot of work to make the frame a little stiffer. The shell helps hold up the frame, but when the floor rots out there is nothing holding up the frame. Like what happened to mine..

I had some 3/16 bent into an "L" shape. and welded it inside the frame rail in 4' lengths. 8' on either side. Started in the middle of the axles and went back 8'. This stopped pretty much all flex in the rear of the frame. I had the top 1 3/4 and then down the side was 4 1/4. I put a continuous weld along the top and 4" tack welds on the sides.

This guy went a little over kill on all the bracing. All you need to to is beef up the main rails running from front to back. you can see what I did in my thread I posted earlier.

[mrgreen]

my frame on my 69 was in really bad shape, the backend was a write off up to the second to last outrigger, from 16 outriggers 12 were rusted out, the front under the rails was gone and the cross beams between the main rails by the axles were bent as if the axle was not working an´d the cross members took the hit, so I decided to build a new beefed up frame. if your frame is o.k i would certainly beef it up a bit as my personal belief is that the frame is rather flimsy and the main support comes from the flooring itself, as for the monocoque the jury is out for me on that one i still don't believe that the support that my shell could give to the frame would be off any value as half of the rails don't even go to the floor!

[dkrukosky]

I am struggling with similar questions. I am down to the frame on my 75
http://1.bp.blogspot.com/-LAh7_LnUsh...0/100_0808.JPG
so what would be best for frame reinforcement? putting a c channel inside the original main frame C channel or is it better to box it in? or both?

[Wabbiteer]

dkrukosky - that is an excellent question worthy of its own post...

[mrgreen]

Originally Posted by dkrukosky

I am struggling with similar questions. I am down to the frame on my 75
http://1.bp.blogspot.com/-LAh7_LnUsh...0/100_0808.JPG
so what would be best for frame reinforcement? putting a c channel inside the original main frame C channel or is it better to box it in? or both?

c channel is the easiest but heaviest option and i'm not sure haw you'd go about painting that , boxing in is definately the lightest way to go but a little more work for sure, i would go for boxing in, on my new frame i still have C channel but it is 24 gauge (4mm) even so it still has alot of flex in it. I had my frame galvanised which was suprisingly cheap and definately worth looking into, it was cheaper than por-15 (here in Europe anyway!)

[Tony S]

I thought I would give a quick update of my progress on my 1973 Tradewind. I will start separate renovation post but wanted to show that with your help and encouragement I have moved forward. I still have a section of belly pan to drop but I have pulled the fresh water tank and check out around the dump valves. I have also worked on taking about the inside but I will save that.

The frame was not a rust out job that it could of been. I have been quite happy with what I have found. I pulled the fresh water tank and found some real rust on the z metal but I will take care of that after cleaning it up with Por 15. The rest is mostly only lightly rusted. The plywood under the tank was in great shape. I will sand it a bit and epoxy the edges and fill the hole where I put the eyebolt to come-a-long it out. Which went easy.

See pic. So I am making decisions on how far to go with the project and will address it later

One questions I have what is the best bet with the lightly rusted, mostly still painted, good section of the frame? Clean up a bit and rattle can Rustolem or Kyrlon ?


Anyway I have broken the ice. thanks

Tony

Rogue River, Oregon

[Wabbiteer]

...what is the best bet with the lightly rusted, mostly still painted, good section of the frame? Clean up a bit and rattle can Rustolem or Kyrlon ?

In Oct. 2011 I posted "Also am seeing DeRusto flat-black aerosol was very ineffective - many of the inboard spars I only quick coated since they appeared 'nearly' new now have orange rust spots blooming all over them so they are on the paint list."

I saw lots of dime sized rust 'flowers' appear within 3 years from the first time I first repainted my frame, so I'll forward a glossy sealed NEW finish is important.

The paint on my '73 frame was a hybrid asphalt/creosote undercoating, that is judging by what slung off the wire-wheel brush and stained my hands. Whatever solvent/carrier in the paint you overcoat it with will change the way the original lies AND change the paint applied. The light rust pits will continue to react under the new paint, knowing what I've seen here I'd be tempted to wield a phosphate conversion treatment before coating with anything.

Give each coats a couple of days to dry & cure thoroughly before you recoat to keep the waxes in the original paint from floating into the new layers.

[Tony S]

Thanks for the reply. It is kind of where does it end before getting started.
Seriously though what is "phosphate conversion treatment before coating with anything" Is that the Por 15 Marine clean or metal ready?

Tony

[Wabbiteer]

If you want to make it last another forty years do the coating before the paint. If it's good enough in your considered opinion, paint it and keep on marching

The marine clean is a very good detergent that lifts oil films - the metal ready is a metal treatment that leaves a grainy surface on bare metal that paint gets a good grip to anchor to ie: "surface profile".

There are other phosphate treatments, though I saw the derusto type get undercut and nearly perforate my F-150's differential cover because it also has a clear plasticy film in it - looked gorgeous black while MN road salt was eating through the metal behind it. Not again for this camper.

if there is a auto body/speed shop nearby you they may have POR Metal-Ready or something equivalent in stock. The warmer is it when applied the faster the reactions. If I was doing again I think a wet sponge - scotchbrite pad scrub of the old paint with the Metal-Ready, hose rinse and allow to dry then paint away with puff-can paint

[Tony S]

Napa Auto parts handles a similar product at a similar price. I also went to Sherwin Williams and the had a similar product. I have the Por 15 in the cart at VTS along with some other things like elevator bolts and a Fantastic Fan. I am going to get a beer and sit in the trailer for a while and try to come to a decision on which of my plans I am going to pursue with it.

Thanks Wabbiteer

Tony

[Wabbiteer]

Re-reading my response seems I omitted that Metal-Ready was a rust converter too, as well as a paint prep magic ingredient that makes POR-15 grip like a cat above a pool of water.

[RestoWarrior]

Also consider a product called Zero Rust. It is a high solids coating used on industrial equipment. A good alternative when you don't want to mess with POR products.

[Frank's Trailer Works]

I have tried just about every product on the market. I somehow want to find something cheaper, but nothing works like POR15. I would honestly like this to not be true. Unfortunately POR15 it the best there is. It is worth every single penny.
A hint for making the most of your product; Use black for the first coat and grey for the second one. This allows you be sure you cover everything.
Another hint; SPRAY IT. It goes on great and very efficiently.

[Tony S]

I ended up ordering Por 15 the cleaner, the etching stuff, and a can of top coat from VTS. It is on the way.

I also picked up a couple can Rustolem spray primer, qt of primer and qt top coat from Lowes. It should get me started on the various rust situation I have found on the frame. I am so pleased no rot out.

Tony

[perryg114]

The frame is not the problem so much as it is poorly attached to the shell. So you can do one of two things, you can make a beefy frame that is capable of supporting itself without the shell or add more outriggers and connect the ends of the outriggers with something like angle iron or other types of structural steel. Then you need to put fasteners every few inches (not feet like they are now) between the C-channel at the bottom of the shell skin and the steel between the outriggers.

As someone said above, the back end rots off the newer trailers because of the plate in front of the bumper that funnels water under the rear of the trailer. The main frame attachement to the shell is at the back and when this rots out the frame is supported by the outriggers and they are not made to hold much of anything. Now add the weight of the bathroom and the holding tanks you have a problem. If you add a gray water tank, I would move it in front of the axel.

Perry

[M2HB]

I think that Airstream relys to heavily on the structural support of the shell. I can't recall any of the other aluminum aircraft style travel trailers using as light of a frame as Airstream does. None of those others are regularly doing shell off restorations either. I think that Airstream added too much weight to the later model trailers without making the frames stronger. It is just an observation from someone who has built a lot of equipment trailers over the years.

[perryg114]

Yes they rely on the shell but the connection to the shell is not adequate. There are only two areas where there is anything like a structural attachment point and those are at the front and the back. Once the weak connections break down, and they do, the frame is supporting itself. There in lies the reason for tail sag. To get strength the shell and frame don't need to move relative to each other. Once they start moving relative to each other, all bets are off. The shell does very little at that point.

Perry

[Frank's Trailer Works]

I am going to say this one more time for all the arm chair engineers determined to re engineer things....
Airstreams are ENGINEERED TO FLEX, TWIST, AND CURVE AS THEY GO DOWN THE ROAD. They are not like a white box trailer. They are not like a flat bed trailer, they are not like your house at home. They are designed the way they are for a very specific reason. Beefing up, changing, altering is not a good idea. Over and over I read people saying how they think they need to beef it up, make it stronger, make it thicker. It is your trailer and you can do to it what you want, but I strongly suggest you rebuild it exactly how it was originally.

The biggest issue you guys with the 1970's trailers have is that the quality of the steel used is inferior and very low quality. It tends to melt away with exposure to moisture. Some batches of steel were good, but many were not very good at all.

[perryg114]

Well Frank I am a real engineer with real degrees and I don't sit at a desk all day. I am in the lab doing things and designing things and building things. I have studied structures and built structures. Yes you are correct all real structures flex and twist even bridges. In the 60's these trailers were built better with better materials and better workmanship. They also were not as heavy. They changed a bunch of stuff in the 70's and did not update the design. Wet fiberglass rusts the frames on these things. If you put wet fiberglass against any type of steel for 40 yrs IT WILL RUST. If you are going to accuse someone of being incompetent you better be able to back it up with something other than arm chair commentary.

Perry

[Frank's Trailer Works]

You are right! I sit in my arm chair and comment on fixing rusted frames all day. I also sit in my arm chair and comment on lifting shells. I advise on axles from my arm chair also. I never actually touch a thing I comment on, I do it all from my arm chair. Thank you for straightening me out. The truth is, I do it from my couch. I don't own an arm chair.

Folks, please disregard anything I said previously. Box those frames in and make them as rigid as possible. They are weak weak weak...