Prep for passivation

While I'm waiting on my crankshaft cap bolts and some seals from Toyota (on backorder from Japan) to finish the engine reassembly, the block etc has been wrapped in plastic and I've collected up every nut, bolt & washer I have removed from the two Minis and Starlet front cut (plus a few small pipes and brackets from both cars too) and plan on getting everything gold passivated. Car manufacturers fit zinc plated and gold passivated metal components to vehicles and not just for show. Zinc plating serves to protect against corrosion, while gold passivating adds further protection plus an attractive long-lasting surface finish. You can get the coating in zinc, gold, blue and black colours but to retain the factory look, I will use gold. I've sometimes seen engine installs done where they have either painted the entire engine (and bolts) in one colour, or painted the engine and resued the grubby fasteners. I'm not building a show car but it's this extra attention to detail with the fasteners which most people simply won't outright notice, but takes the build up a notch :)

It's quite cheap too. A local shop here in Perth have a minimum charge of $60 which you can get up to 30kg of components done! The best results of passivation comes after all items are carefully prepared and cleaned. Areas with surface rust, imperfections and heavy grease need to be sanded back or wire-wheeled. The actual passivation process will remove any light oil or grease.

So after 7 hours of wire wheeling on my bench grinder (with a few breaks to allow the grinder motor to cool down), I've cleaned up a massive 17kg!! of fasteners and a few brackets but still have some other Mini parts to add to the pile.

This is a 9 Litre bucket about 2/3 full of fasteners :

As an example of how well a lightly rusted component can come up after being wire-wheeled, here a before & after pic of some brake lines connections.