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Shaun @ Tru6 Shaun @ Tru6 is offline
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Join Date: Dec 2001
Location: Cambridge, MA
Posts: 34,360
Restoring a set of Turbo Calipers

I was given a set to restore a few months ago but they were in such bad shape, we ended up Cerakoting them vs restoring to original anodized condition. Those turned out beautifully but when I received another inquiry on restoring a set, I was eager to see how they would turn out.

Calipers as received. Notice how the piston housings are darker than the bridges. Turns out they are different aluminum alloys so they anodize differently and take up color differently. Did a fair amount of testing with various processes to even out the color but they will never match 100%. My anodizer does a lot of military work and we ended up using some special chemistry for a certain black helicopter. I, and more importantly the customer, are happy with the results.

After disassembling, the seals and scraper rings had to be removed before stripping the old anodizing off. Seals pull out easily. Factory technique for removing the rings is to dent them with a small chisel or punch. I made one and it worked ok. Better process was to grab the lip of the ring with a small pair of wire cutters and twist. Doing that a few times shrinks the ring and they pop right out.

Caliper pieces stripped of anodizing. As with window frames you want to be as gentle as possible with the stripping solution as it will start to attack the bare aluminum while other areas still have anodizing. Better to chemically strip as best as possible with minimum attack and then physically remove any remaining anodizing. The goal for these was when the piston bores were clean, they came out of the stripper.

Tru6 Restoration & Design

Last edited by Shaun @ Tru6; 01-23-2019 at 04:58 PM..
Old 01-23-2019, 03:25 PM
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