December 2020

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DECEMBER 2020 WWW.PNWR.ORG 15 Chemicals Used in My 1964 356C Porsche Restoration As this pandemic drags on, Dennis Rood invited me to write a couple of additional follow up articles that go into a little more detail on any unusual chemicals and tools I used in my Porsche and Volks- wagen restorations. One of the reasons the restoration of my 356C took 13 years to complete is that I have become a car hoarder! I built my dream shop and added eight additional project cars to my collection between 2007 and 2016. My wife jokes that nine-year second bachelorhood was my "period of no adult supervision" and I joke she knew what she was getting herself into! My five air-cooled Porsches and six air-cooled Volkswagens compete for my time, which feels like a full-time job, but it doesn't feel like work. Rust Arrest – Porsches built before 1976 were not protected by a zinc coating from a complete immersion in an etching bath, so anywhere not covered by paint or undercoating is bare steel. If the car was in a climate where condensation could form inside the body cavities, it has flash rusted and you'll find a thin layer of surface rust. Areas where debris like pine needles or leaves has accumulated and blocked drain holes, such as the bottoms of doors and rocker panels, can never completely dry out. In addition, there are problem areas that have several layers of overlapping metal such as Targa/Cabriolet stiffening panels and pinch seams like door skins. That is where you'll find rust bubbles as it rots from the inside out. The only way to fix rust bubbles is media blasting or cutting them out and then welding in new metal. Surface rust is a different matter and can be chemically trans- formed into a protective layer using a product by SEM called Rust-Seal (product code 39308). Rust-Seal is a green liquid that turns purple as it reacts with the rust and then turns black when it's dry. Once black it can be considered a primer for coverage with a sealing layer such as undercoating. Pre-1970s Porsches used a thick splatter coat of asphalt-based undercoating that can grow brittle and fall off in chunks, exposing bare metal. After thoroughly cleaning and removing any loose pieces, sealing exposed metal with Rust- Seal is the first step to a technique I've dubbed, "faux factory undercoating". Two products make it possible to preserve the remaining original undercoating by patching it. 3M Ultrapro Sealant 08300 seam sealing caulk is 'dabbed' over the Rust-Seal treated spots to look like splatter patterns where the original undercoat is missing. Once the seam sealant has dried a couple coats of rubberized Wurth Hi-Build Underseal over the entire area hides the patched areas and re-seals the original undercoating with a protective layer that also makes it look like new. Paints and Dyes – These products are great for matching original colors on early Porsche components. I personally think powder coating is overkill for any part on the car that doesn't come in contact with gasoline. Engine cooling tins around the carburetors are the only areas I find worthy of the extra expense of powder coating. The downside of powder coating is the thickness of the coating and the loss of details, such as manufacturing date stamps, also when it chips it comes off in big pieces. The thickness of powder coating is a real safety issue with steel wheels, as the lug nuts have been known to come loose when the coating chips away in the cup of the lug holes. I have found that PlastiCote wheel paint (product code 621) in "Silver Argent" most closely matches the factory color. When applied over freshly media blasted wheels it shows the date code and maker stamps very crisply because it is paint as originally done. continued on next page

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