Welding question / structural rust

[alabbasi]

Gentleman (and ladies),

This is a 1973 Mercedes Benz 280CE. It's not an expensive or collectible car to many, but to me it's valuable because it's fuel injected and a stick shift which are options that were never made available in the US.

It's a pillarless design and is a uni-body construction.

The car lived in Chicago for many years and has suffered from rust , especially in the drivers side pan.

I've bought new pans and rocker panels but I have a dilemma as to how to cut it up.

Here's the deal.

I was able to get replacement floor pans that run across the whole drivers side of the car (front and rear seat). This included the inner rocker panel for that area.



I was also able to buy a replacement outer rocker panel and my existing floors need it because they look like this









My concern is that if I cut the floor and the rocker off, will the car collapse given that it's unibody and also a pillarless design?

You're thoughts are gratefully welcome.

[JPB]

I've seen worse cars repaired without losing their shape. A couple of diagonal braces - made from angle iron - forming a cross over each door aperture could be tacked in to hold it while you do the welding to the rusted parts, that should be sufficient.

[SEE YA]

I did the same for my wife's Karmann beetle when replacing the bootfloor .

[Luxobarge]

Given that any distortion will effectively write off the car, I'd play safe and do as above, weld in a couple of diagonal braces into the door apertures. Doesn't take long, and given the amount of work you're into there, grinding off and painting the places on the body where they've been welded afterwards isn't going to be much of a hardship eh? Also do one side at a time.

BTW what's a rocker panel? Rockers are part of the engine over here..... From your pictures maybe what we'd call a sill?

Cheers mate

[SirTainleyBarking]

Two countries separated by a common Language mate!

Rocker Panel =American Sill

[rich.]

every days a schoolday..

[Luxobarge]

Two countries separated by a common Language mate!

Rocker Panel =American Sill

Ah right, ta. IMHO "Sill" (or its alternative spelling "Cill") os no more a sensible word than "rocker panel", but you get so used to our terminology it seems natural eh?

Wing?

Bonnet?

Boot?

They all have their roots in logic, but car design and technology has changed so much that actually they're really odd words to use for parts of a car these days when you think about it!

Anyway, sorry for O/T - all the best with the Merc Al.

Cheers

[JPB]

Just don't, for the love of the flying spaghetti monster, ask an American what their name for a bum bag is....

[m.thaddeus]

Hello There

I have never known why they had to invent the American word 'Zuchini' when we have a perfectly good English one - Courgette!

But back to the repair.

Brace, Brace, Brace. A set of expanding braces is worth investing in. These can be clamped across the aperture and allow for the door to be closed as required.
Also a small jack on the transmission tunnel to support the scuttle/bulkhead assy, wouldn't go amiss.

If you do decide to replace the Sill, leave it insitu until the floor pan has been reinstated so as to minimise the weakness.
Usually the best place to cut-in a floor section is over an out-rigger or chassis member.

Whatever you do: Keep the car well supported and level. And check the fit of the doors at every stage.

[jimmyybob]

I have seen some braces that bolt in place of the door hinges and then lock onto the door latch plate in a triangle shape, effectively replacing the door with a steel frame.