Getting ready for the rebuild
After I had removed all the burned components and wiring the car still was filthy. A quick hand wash made a big difference already.
So by the end of August 2022, a bit over a year after the fire the car was clean enough to go inside again.
Polishing and cleaning the stainless steel bumpers was quite straightforward. The engine bay turned out to be be bigger challenge. I tried various solvents and cleaners but the remains of the smoke were difficult to remove. Also sanding did not work out since then the dirt got into the paint and spread all over the place. I did not want to use a wire brush too much. In most places the zinc coat, epoxy and even the top layer of paint were still OK so I wanted to preserve that. But in some areas all these layers had burned off and there was surface rust.
The solution: dry ice cleaning
A while ago, Robbert-Jan informed me that he added dry ice blasting to his portfolio (check out stralenmetdroogijs.nl and his Facebook page). I came to the conclusion this might be the perfect approach for the Volvo.
Dry ice is in fact frozen CO2. The combination of the impact and thermal shock loosens any dirt and soft materials such as rust and underbody tectyl. It does not fully remove rust so the areas that are too rusty may need to be treated by traditional media blasting.
The process of dry ice blasting
The dry ice itself is produced externally (often using CO2 captured from industrial processes) and can be kept/stored for a couple of days. The dry ice goes into the blasting machine.
No dust, just cleaning
Perhaps the main downside of this approach is that due to the fact that the metal cools down, water condensates on the surface. But other than that it is great!
All loose bits and pieces and dirt are removed and only the solid bottom layer remains. Below you can see this in two videos.
As you can see it does not remove deeper layers of rust. So Robbert-Jan has used traditional media blasting to remove the rust in the engine bay and treated it. So now it is clean again, ready for a rebuild!
Thanks Robbert-Jan!
