Correct. The casting is a zinc-alloy with nickel substrate and the gold plating over that. Owners
often and incorrectly think it's brass and use abrasive brass polish that rubs through the gold leaving the nickel showing through. I ultrasonic clean everything using
Blitz cleaning solution and the results are amazing. After the tank, I wipe down everything with a non-abrasive dish washing sponge, very warm water and a spritz of dish soap, thoroughly rinse and dry. A buff with a jewelers gold cloth finishes the cleaning job. I wipe it all down with alcohol and then coat it with
ProtectaClear by Everbrite. You can also find it on
Amazon. It's a product specifically for polished metal of all types that seal it completely from tarnish, dirt, dust and everything. Two light coats applied with a sponge brush covers the gold surfaces beautifully. There is a learning curve to apply it smooth, but especially keep the sponge brush barely damp. Don't be tempted to load it up, that causes areas to run. Also, very, very light strokes work best. I almost use the weight of the brush alone and just pull it along. It's best to keep all the brush strokes going in the same direction too. Goofed areas can be wiped down with a bit of acetone and reapplied. Keep an eye out for dust bunnies and other atmospheric floating stuff that will stick immediately to the drying surfaces. My cat that doesn't shed much at all, can walk through the room, 8 feet away and leave moisture seeking fur that finds my work piece instantly.
ProtectaClear has a gloss finish that tends to minimize the appearance of areas where the nickel substrate shows through by giving it an appearance of depth. ProtectaClear only needs a dusting to keep the glow to it and a
water dampened paper towel for actual dirt or liquid splashes.
It take a two-step approach to dealing with worn areas of the chapter ring. I would really worry about using any type of mechanical force to get it back 'in round' in that zinc castings are notoriously brittle due to interstitial corrosion with age. It's the same process that creates the dimples pushing through to the surface of the casting. The alloy helps some, but it is a formulation from the 40s. First, I build up the primary wear areas including the vestigial pads with about a 3mm strip of
single adhesive-sided teflon PTFE tape, cut to about 5 1/2" and placed from 3:30-7:30 on the chapter ring. I push it back from the curved area where the drive gear meshes the ring and don't cover the wear-pad areas, instead use smaller pieces of the tape on either side. I remove, clean the notched out area for the nylon pads if used, then replace it with new ones using a small drop of super-glue. I hold the edges of the pad with tweezers and drop it onto the glue surface and quickly square it up. Ensure the tape runs along the track true and doesn't ride up on the vertical edge of the chapter ring. Carefully trim the ends so there are no lone fibers sticking out where the tape could be caught by the drive gear. Burnish the tape a few times to get the best adhesion and to smooth down any areas where it might have buckled a bit. Don't be tempted to cover more of the chapter ring with tape. The tolerances are reduced with too much tape and will bind the drive ring assembly. Following this, I put (2) coats minimum of
Neolube #2 on both inside surfaces of the chapter ring, including the tension spring beds. Neolube is an awesome product and used extensively for dry surface lubrication in the nuclear navy (where I came from these many moons ago), which it was developed for. It is a colloidal graphite suspended in alcohol solution that leaves a thin, dry and tough film of graphite when the alcohol evaporates. I use a slender artist's paint brush or lint-free q-tip swab to apply it. I cover everything with it including the nylon wear-pads. I also coat the drive-gear, toothed and flange surface that rides on the tension springs and the springs themselves once they are dropped into place. Any areas where it's accidentally applied and unsightly, can be cleaned quickly with an acetone dampened swap. Neolube on the glass surfaces comes off easily with an alcohol swab. Obviously, these steps are time-consuming and fussy, but the result is a noticeable reduction in the friction between the drive assembly and chapter ring. Through testing I've proven this works by seeing increased accuracy of the clocks, quieter and cooler running motors that should add up to an extension of the motor life.
(3) coats of ProtectaClear and you can see the appearance of 'depth' on the surfaces.
I hope these tips are helpful to someone and would love to hear about any others folks have come up with.
Cheers-
