The first steps
The chassis has been cleaned down to the primer, or when necessary also down to the metal. Most of the rust was known but of course some "new" attacks were found. There has also been quit a lot of work cleaning up old repairs, done by my father and Mercedes-Benz in Stockholm. Some of the rust attacks have only been stopped by my father; that is, not repaired only covered with metal plates and/or puttied up.
These repairs were done during the late 60ies and during the 70ies and was done to get the car back in traffic as fast as possible. This was however not enough for my purposes and was re-made. Luckily he also filled the car with Tectyl of different shapes, which have effectively stopped more aggressive rust attacks. Due to that, the welding costs will not be as high as normal for a Ponton which has over 300.000km on partly salty roads behind it.
Mercedes-Benz Ponton Rahmen-Bodenanlage, frame, 220a, © Daimler AG
The first stop was the engine compartment. Here you can see that the fire wall needed repairs, as well as the left scoop for heating and ventilation. The radiator mounting is bent at this time but is now fixed. For a long time we thought that the front tube beneath it was OK. That was unfortunately wrong and was thoroughly repaired.
Next, I rolled the car over and cleaned the underside of the car. During this cleaning I found most of the unknown rust.
When the engine bay and underside of chassis were cleaned I spent ~1 week in the coupe. The floor was almost perfect. The most aggressive rust attacks had hit the fire wall including the glove box. I hope you'll never have to clean that part yourselves! The bare metal was then covered with a 2k primer.
This is how a totally cleaned and primed boot can look like. Beautiful isn't it? The spare wheel recess was in pretty good shape but some of the welding recess/boot floor was remade. The centerpiece was replaced due to rust and loose exhaust pipes!
And then came the Welding...