PC-21 / Photo Dial Primer. Well.. sort of.

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cw

newbie first breath.

Ricky Lee-

I joined the PMWF because I have a couple of questions it looked like you could answer off the top of your head that would take me more than a few months to ferret out answers. I got to one of your posts when I searched for PC-21 [movement type] and found the PMWF.

in that series of posts, you mention a trip down to WalMart to print out a watch face. Was that on photo stock or a stiffer substrate? did that go in on top of the existing face or did you directly affix the movement to the face? You mentioned a Japanese made movement (PC-21) that I've found in lots of watches, but it's the extended version. Is that because of the extra depth of the face + WalMart printed overlay?

I want to customize a few watches as gifts for friends and I 'm thinking of buying 6+1spare cheap watches and gutting them. I'm thinking $20 each in parts to upgrade/replace movement and band and maybe the hands.

My list of "would be nice" features in the donor watch is:

screw back.
standard movement
largish dial.
moving bezel
'stainless'

Is there a better path to finding the donor watch than ordering 1 each off the net and waiting 3 weeks to see what I get? Are there any 'reliable' sources you would suggest?

Thanks in advance.

cw

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Ricky Lee

Re: newbie first breath.

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cw
..you mention a trip down to WalMart to print out a watch face. Was that on photo stock or a stiffer substrate?

Plain old photo paper, but it must be affixed to a backup substrate as a single layer of photo paper is way too flimsy. More on this later.

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cw
You mentioned a Japanese made movement (PC-21) that I've found in lots of watches, but it's the extended version. Is that because of the extra depth of the face + WalMart printed overlay?

The high-canon-pinon (or HCP) version, yes. The HCP isn't absolutely necessary, but it makes things a lot easier, and results in a more "standard" construction. Again, more later.

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cw
I'm thinking $20 each in parts to upgrade/replace movement and band and maybe the hands..

It's possible. I can sometimes accomplish it for under $10, lock-stock-and-barrel. However..

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cw
My list of "would be nice" features in the donor watch is..screw back..moving bezel..stainless..

..it's hard to find all three of those features in a really inexpensive watch!

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cw
Is there a better path to finding the donor watch than ordering 1 each off the net and waiting 3 weeks to see what I get? Are there any 'reliable' sources you would suggest?

Well.. first, though buying cases brand-new is certainly possible, I seldom go that route. While not outrageously expensive, neither are they truly economical. Otto Frei is your best bet - they have a good selection starting at $20. Let's call this, brand-new cases, "Option A".

Option B is to find job-lots of "fixer uppers" on eBay. Don't matter if they run or not, and you can get them for 2 to $3 each if you shop carefully. Also, I have developed a network of online friends over the years, friends who are fully aware of my needs. They frequently send me excess cases and fixer-upper watches gratis. The big drawback here is they are almost always one-of. If you're looking to build a series of like watches, this ain't the way to go, as a rule.

Option C is to buy brand-new watches, strip them down, throw away the OEM dial, and substitute your custom dial. This makes it a piece of cake to build a series of like watches, and is often the most economical route of all.

Now. The dials themselves. First thing you need to know is that almost all wristwatch dials are .50 mm (.0197 inch) thick. So if you're using a standard movement (IOW not a HCP) that's the magic number to shoot for. Conveniently enough, photo paper is a nice multiple of The Magic Number, at .25 mm (.0098 inch). OK, we'll number the options here.

Option 1 is to cut out the photo paper dial and affix it directly to a conventional metal dial with super-glue or epoxy. Epoxy is stronger, stiffer, and more forgiving, but super glue is faster. Note that only smooth, flat dials will work. Raised chapter markers of any class are a no-go. The downside is that your dial ends up being .75 mm (.0295 inch) thick, and so a HCP movement is a must. This is really only a problem if you've gone Option C to obtain your donors. The big advantage, of course, is that you can use "standard construction", with the movement attached to the dial by the OEM dial feet. Much cleaner!

Option 2 is to use a DOUBLE layer of photo paper. Just cut out two identical dials, bond them together, and you got your Magic .50 mm (.0197 inch) thickness. Again, epoxy is stronger, stiffer, and more forgiving, but super glue is faster. Place the dial between wax paper, lay a thick book on it, and Bob's Your Uncle. This results in a much stiffer dial than you probably imagine! Not as stiff as metal, obviously, but plenty stiff enough to be perfectly functional. This is the way to go with case Option C, as it allows you to re-use the original movements. No dial feet, though, so you must affix the movement directly to the dial with epoxy. Do NOT try super glue here! And keep the epoxy on the outside of the joint only. Trying to place epoxy between the movement and dial is a recipe for disaster! I use dial dots to hold the movement in place whilst I lay the epoxy.

Option 3 gets tricky. And expensive! But it results in a dial that is the Magic .50 mm (.0197 inch) thickness and does rival metal in stiffness. Start with a single-layer photo paper dial, then lay on 2 layers of .004 thick carbon fiber cloth. Epoxy is also a must here, and for maximum stiffness it's critical that the cloth be oriented with the weave of the respective layers perpendicular to each other. It's overkill in most cases, but if you're a perfectionist & only the best will do... No dial feet here either, so affix the movement to the dial as with Option 2.

Hope that helps, and happy building!

Warmest regards,

-Ricky

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cw

Re: that answer was spectacular.

Thank you, sir. That's a spectacular response....definitely walks the dog. After I've made a few million more mistakes on my prototype, I'll post some pictures...

The idea of doing a carbon fiber layup hadn't occured to me. However, doing a little epoxy lamination of the paper layers was flirting with the roll of alumninum sheet rolling around in the back of my truck.

The bump in price to get the HCP movement isn't that steep, and seems like a good idea for most anything I'd want to do.

Most appreciatively--

CW

Happy modding all!



-Ricky