Frame Rot

[monocoque]

Originally Posted by Inland RV Center, In

Rear end separation also doesn't happen when the running gear is properly balanced.

Since you have the trailer taken apart, you should do the rear end modification, so that you don't have trouble later.

Andy

Andy, can you explain what you mean by the rear-end modification? I'm not familiar with this modification?

[monocoque]

Originally Posted by Jim & Susan

One thing I wished we’d done differently: use only stainless fasteners everywhere we could.

A couple of questions. I have to admit, I skimmed thru parts of the thread, so forgive me if you already answered these. Are you going to POR-15 the new frame? It’ll be a lot easier on a new frame with no shell to work around. Are you planning on closing up the ends of the box steel to keep moisture out? Seems like that would be easier that trying paint/POR the inside of the box.

Jim

Thanks for the support and observations Jim. There is a bolt and fastener supply house I enjoy shopping at just around the corner from the office. I like going in there from time to time and making unusual requests. They really looked at me funny recently when I asked for Olympic rivets! So I'll definitely check into stainless steel fasteners.

I did buy POR-15 at the very beginning before I realized how far the rust was involved thinking this project was going to be a relatively simple repair. I had no idea! So I'm already with POR-15. I even have two colors for a second coat. Triple S steel, the grocery store for steel, had some metal cleaners and primers I plan to check into as well. The raw steel is very dirty.

I'm not sure about closing off the frame? My initial hunch is to cap it off. On the other hand leaving it open would allow it to breath should moisture begin condensing there. So I'm not sure. I'll see what welder thinks.

[Aerowood]

Close off at least the forward portion of the "A" frame as it is an interstate highway for mice into the belly pan area along with water spray from the tow vehicle.

[Wabbiteer]

The POR-15 metal treatment for new surfaces is a potassium hydroxide degreaser and then phosphoric acid w/ an added zinc phosphate kicker to help the POR-15 get well anchored to the new surface. Both steps are water based.

If you want a forever paint job mimic those steps - though they may not be necessary since POR-15 Corporation doesn't know if you are working in the bilge of a boat or painting a V-8 motor or a park bench.

I used 3M abrasive biscuits chucked into a compressed air die-grinder to scour away weathered frame paint and loose rust - and used an angle grinder to clean up welds - and solvent wiped it then painted. So far no problems at all - though next time I am tempted to try agricultural granular phosphoric acid (pH adjust) in water at a 15-20% concentration with a shot of dry-erase-board cleaner added as a surfactant to treat any bright bare metal, just another thing learned surfing the net AFTER the actual work...

Close the A-Frame yolk up - if box beams are sealed on both ends any condensation possible will rapidly react and that's the end of it.

[monocoque]

Close off at least the forward portion of the "A" frame as it is an interstate highway for mice into the belly pan area along with water spray from the tow vehicle.

Close the A-Frame yolk up - if box beams are sealed on both ends any condensation possible will rapidly react and that's the end of it.

So basically you would agree to leave the rear-ends of the tubes open to some extent? Actually the rear bumper will roughly cover the ends. I should also ultimately find some kind of material that will breath but not leave the tubes completely open for all manner critters to take up residence.

Here you can see the old A-frame, new main rails, and forward cross-member being clamped prior to welding. The ends of the tube are flush with the tube cross-member.

BTW actually the hot wire leading from inside the 7-way connector to the electric jack travels through the A-frame. So I'll probably need to cut a hole of some kind through the cross-member tube to access the A-frame tube. The second photo shows the jack wires entering the front end of the frame. Notice the rust!

[Jim & Susan]

I've heard of folks using steel wool for closing holes like this. Some kind of stainless screen would work better, I'll bet. I was more concerned about the inside of the box rusting if not closed off or painted. My impression is that the main frame rails would be one piece only open only on the ends, is that right?

Jim

[monocoque]

Originally Posted by Jim & Susan

I've heard of folks using steel wool for closing holes like this. Some kind of stainless screen would work better, I'll bet. I was more concerned about the inside of the box rusting if not closed off or painted. My impression is that the main frame rails would be one piece only open only on the ends, is that right?

Jim

Jim, that's right. The main rails are made of 5 inch tube with openings only on the ends. If you look at the photos in post 215, above, you can see the front end of the rail. That rail will eventually need a radius or diagonal cut to allow space for the banana wraps. You can see that radius angle in the second photos which shows the front end of the old frame. I'll need to figure out a way to seal the front of the main rails but still allow access for the wiring to the jack. Here's a little better photo of the wiring route and radius cut in the front end of the old frame.

[Jim & Susan]

Dang, forgot about that wire. My '73 is wired similarly. How about welding a piece of 1" conduit inside the 5" tube with openings on both ends where the wire enters/exits? Then you could seal (weld) around it and the back end of the 5" tube to keep all the miosture out of there. That might work.

Jim

[monocoque]

The welder is out fishing and I've been out of town this past weekend. So work on the trailer has slowed momentarily.

But here's a few fun photos of the levitation. The first photo shows the shell "floating" 5, count 'em, 5 cinderblocks high off the ground on the right hand side! That's about chest level for me. The left-hand side is 4 cinder blocks high. Believe it or not the trailer is level in the photos in spite of appearances due to the grade of the driveway.

The second photo shows the location of the jack just below the 4x4. This was the only jack I used during the entire process. The actual lift was done entirely solo --one man. The jacking point was just inside each cinder block column directly below the 4x4. Note the small level on the 4x4 which I quickly learned was a very important consideration in the process of lifting a shell this high of the ground.

And a couple of photos taken from behind the curbside and roadside columns. And finally photos of the foremost jacking points street-side and curbside shown from the inside.

[monocoque]

The layer cake....

[sfixx]

Great work! Reading from post #1 was great fun and what a journey you've taken


Any idea yet how much heavier the new frame is?

Best wishes,

Steve

[Wabbiteer]

I'd cap the box beam openings front and rear - zero reason to leave back bumper open for condensation via air exchange.

While you have the chance have the welder make a small business card sized area 'double thickness' to accommodate the primary 120VAC ground pad - Mine was located neat the city water hookup and corroded away that iron very fast... perhaps tack in a stainless machine thread bolt as a clamp?

Also - the fold-down step area? maybe tack in some light sheet metal to keep mice from finding their way through the guide slots, etc...

Also - maybe provide some sculpted relief at back beam end for tail-dragging, if it is a sharp corner and digs in backing out of a unusually steep local it might get ugly...

I better desist before I try and reinvent the wheel. GOOD LUCK! !

[monocoque]

Originally Posted by sfixx

Great work! Reading from post #1 was great fun and what a journey you've taken


Any idea yet how much heavier the new frame is?

Best wishes,

Steve

Thanks Steve! It certainly has been a journey.

There are a lot of posts concerning the weight of the new frame. Some of those posts I think I even confused myself. Which wouldn't be difficult to do. So be fore warned but take a look at post numbers: 131, 132, 133, 143, 144, 154, and 183.

Basically, the old frame weighed 1340 lbs. at the CAT scales including the axles. It was suggested that the axles weigh about 400 lbs total. So by deduction roughly the old frame weighs about 900 lbs.

I think I calculated that 150' of 5x2x3/16" tube would weigh approximately 1,222 lbs. That figure is about 300 lbs heavier than the factory frame. My frame will likely be a bit lighter because the outriggers will be fabricated out of lighter gauge channel.

We'll find out the exact weight when I take the new frame to the CAT scales!

[monocoque]

Originally Posted by Wabbiteer

I'd cap the box beam openings front and rear - zero reason to leave back bumper open for condensation via air exchange.

While you have the chance have the welder make a small business card sized area 'double thickness' to accommodate the primary 120VAC ground pad - Mine was located neat the city water hookup and corroded away that iron very fast... perhaps tack in a stainless machine thread bolt as a clamp?

Also - the fold-down step area? maybe tack in some light sheet metal to keep mice from finding their way through the guide slots, etc...

I've been wondering what to do about the fold-down step outriggers? Seems like I saw step-outriggers, with the groove, for sale somewhere but I haven't been able to put my finger on them? The old ones are still in pretty good shape but the "catch" in the guide slot is beginning to wear out. I thought I would replace them. I'm not sure how to go about tacking in sheet metal because of the moving parts? Looking at the photo I think you can see what I mean.

Also - maybe provide some sculpted relief at back beam end for tail-dragging, if it is a sharp corner and digs in backing out of a unusually steep local it might get ugly...

The old frame had what looked like 3 inch angle welded to the bottom of the main rails extending from the bumper to the behind the axles at the axle plate. In the photos you can see what this skid looks like. The new frame will have skids made from 3 inch channel which will be stronger material. What do you mean by sculpted relief?

BTW in the last photo you can observe one of the very "first glimpses of frame rot." This was how it first appeared after I removed the rear curbside banana skin.