Flexaret III project - plating question

NWT Ron · Jun 18, 2016

I've been picking away at a Flexaret III that I didn't store properly and has corrosion problems. The lens, shutter, and most of the hardware is in reasonably good condition. There are places where corrosion has damaged the finish of the metal, the leatherette has peeled off in places and has discoloured from the corrosion, and some of the chromed parts have corroded.

When I started working on it I had serious doubts in my ability to restore it to a usable condition, Now I'm well into and learning to appreciate mechanical camera construction. Now to the question. Having removed most of the corrosion damaged chrome plated parts what are the options to restoring the finish? Should I even consider a home plating kit, and if I do would the damaged plating need to be removed before new plating is applied? As restoring it to original isn't the goal, should I look into something other than chrome plating?
Ron in Yellowknife, NWT, Canada

AgX · Jun 18, 2016

To my understanding for electrolytical plating one needs a uniform base materialwise. With local corrosion this cannot be achieved without further abrasion to the base material. A likely unpleasing result would be the case, aside of the corrosion as such already rendering an unpleasing result.
Thus all affected planes should be grinded all over.

I assume chrome plating (in contrast to other metals) far fetched for the uninitiated amateur.
(But this may be said of some of our photographic processes too...)

Michael Guzzi · Jun 18, 2016

Chrome plating is way out of the amateur's realm. It is a complicated, hazardous process, and not cheap. My father used to work in a shop that did chrome plating (the "hard" type). Mostly the parts would be for hydraulic cylinders and such, but there were decorative parts sometimes, like car wheels, bumpers etc. He was the cylindrical grinding machine operator (oddly the parts were ground before the plating, and afterwards just sanded on lathes for the final "sheen")

It may not be necessary to strip all of the finish off, but the plating will want to stick to all of the surface equally, thus the chrome guys will have to "mask" where you don't want any more chrome to adhere. Part has to be thoroughly clean too (no grease dust etc) or the finish will be impaired. Also any imperfections on the original surface (grinding marks, dings, bumps) will be amplified in the plating process. But I think the best idea is to strip all old chrome first.

Removing the old plating may be possible with some sort of chemical bath instead of abrasion, I don't know for sure.

AgX · Jun 18, 2016

With corrosion I thought of pit corrosion. Otherwise local polishing may be sufficient as preperation.

But then still there would be different base materials (brass/chrome) at one plane. This might hamper the outcome.

NWT Ron · Jun 18, 2016

Thanks for the comments on the chemical toxins concern skills required for a good chromium plate job. Given the odd chape of the pieces, one of them being the arc shaped distance plate of the focus I wasn't sure if chrome plating would work without removing what was left of the old chrome. There is some pitting on the various pieces, including the film advance lever (that area was covered by leatherette).

Are there option? I'd like to be able to read the focus scale more than I want it to gleem in the sunlight. The desired result is to stop the corrosion and have a clean finish, not necessarily the original finish. I wouldn't hesitate to send the bits out to a professional shop and hope that the cost is reasonable I could attach a photo but I left the disassembled camera at work (its a lunch hour project).

onre · Jun 18, 2016

For the focus scale I would probably give it a mild acid bath and gentle scrubbing afterwards to get rid of the rust, then neutralize with water. The scale is probably engraved, so if you want, you could apply very carefully thin black paint in the engravings to make it easier to read. After this has dried, matt lacquer finish will keep it from corroding again.

Good luck with the project, Flexarets are great little cameras!

NWT Ron · Jun 18, 2016

I'll try that. the corrosion is uneven with the worst of it at one end.

John Koehrer · Jun 18, 2016

onre's correct but all of the plating has to be removed. I believe there may be some plating kits out there
but have no idea if they work ell or not.
Check for threads on repainting cameras the preparation's the same. If there's nothing here,
rangefinder forum's got one or two.

onre · Jun 19, 2016

Not that it matters much, but I'd guess that the part is actually nickel plated, not chrome plated.

Michael Guzzi · Jun 19, 2016

I looked up a bunch of sites that sell kits for plating etc and I think any of those is going to cost more than the camera would be worth.

Personally I would do as onre suggests.

If you do want to "restore" it leave it to a pro shop, probably will cost less than any decent kit, and you don't have to worry about blowing yourself up with the hydrogen gas that comes from the electroplating bath, let alone the nasty chlorine. Plus you get a professional result. The parts are rather small, maybe, just maybe, the shop will do a special price to you because of that.

NWT Ron · Jun 20, 2016

I'm going to take photos of the corrosion when I get back to work tomorrow and post a couple of them.

NWT Ron · Jun 20, 2016

Hee are a couple of photos of the worst of the corrosion. I thought that the range scale was chrome plated, I'm not so sure about the film advance lever, does nickel plating come off in hard flakes? I'd like to have them look nice and to have the range scale to be readable, and the biggest obstacle to that it seems to me is removing the corrosion and the old finish without damaging the scale more than it already has been.

onre · Jun 20, 2016

Try the acid bath method. I've used household vinegar (10% acetic acid) overnight, then next morning I've used toothbrush to scrub off the rust. Hard flakes sound like chrome plating.

NWT Ron · Jun 21, 2016

I'll try that, no problem finding acetic acid. If I get all of the plating off then I must decide what to put back on in it's place.

Flexaret III project - plating question

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