Wednesday, December 20, 2017

A pewter lapel pin

I've been mulling over this as part of a Halloween costume since I finished reading Doctor Zhivago a few months ago.  Early on in the 1965 film version, Pasha Antipov (Tom Courtenay) wears an unusual pin on his hat, a crossed hammer and monkey wrench, during his not-Bolshevik labor movement activities.  I've so far failed to figure out what organization this emblem belonged to, if indeed it was a real emblem (it's been so long since I've seen the film that I can't remember if it's explained onscreen), but a closeup publicity photo (inset) gave me a degree of detail which I attempted to copy.

I made the copy in wax, piecing it together and trying to keep its profile in proportion to the film version, but deeper from front to back for strength, with no undercuts.  Then I dabbed thin plaster into its front face and placed it face-down in the cutoff lower quarter of a plastic cup full of plaster to make an open-topped mold.  Once the wax was hard but still felt a bit damp, I peeled the wax out.  Two days later, I put the mold in a low toaster oven for an hour and a half to try to drive out any remaining moisture, and three days after that I figured it was time for casting.

I intended to use lead-free pewter, of which I had a small amount left over from making an akinakes chape for Marathon 2011.  But I couldn't find it in my house, even though I swear I saw it not long ago.  With no other option, I picked up some low-temperature solder at a hardware store - this is a lead-free, silver-bearing alloy, but it still had a low melting point of 430 degrees Fahrenheit.  It wouldn't surprise me if the one used in filming was a cheap white metal as well, though it could have been brass - it looks silvery to me in color screenshots, but as I well know, photography doesn't always accurately reflect actual colors.

Next I made a small pot for the actual melting and pouring of metal.  This is a 1-1/2 inch copper end cap, annealed and with a spout beaten in by means of placing the cap partly over a cross-peen hammer and smashing it into a block of wood.  Then I drilled a hole in the back and in the end of a piece of thick brass strip, and attached them with a copper rivet peened on the outside, over an anvil horn at Bucks' metal room.  Since the brass handle still conducts heat, it has to be handled with thick insulating gloves or a pair of pliers.  The pot may be heated on a stovetop or over a gas flame, which is what I did here, balancing it between two firebricks.

On my first attempt, I put way too much solder in the mold, giving it a large blobby back.  Attempting to scrape off the excess damaged the rapidly-cooling casting.  The mold broke on the first casting - perhaps it was still too damp; my foundry professor tells me that investment for jewelry is usually baked for around a whole day.  Or perhaps it couldn't withstand the heat even when dry, or my first attempt at divestment was what cracked it.  In any case, it was clear that I needed to try again, so I shoved the broken casting back in, held the mold together by wedging it between a pair of firebricks, and remelted with the gas torch.

Possibly as a result of the damaged mold, there's a lot of flashing below the hammer's head, which, as you can see, detracts from the striking appearance of the crossed tools.  I could probably file it out, but it would take a long time, and I think that the hammer's skinny neck, supporting the relatively massive head, would be prone to breaking without the flashing to strengthen it.  Also, obviously the threaded middle of the wrench isn't as finely threaded or clear in detail as in the film version - the former being the fault of my original wax (it's not easy to cram such fine detail into a wax model) and the latter either because of me failing to work the plaster between the grooves as thoroughly as necessary or because the solder failed to flow into every crevice.

The proportions are slightly off, but I think adequate for a homemade costume - of course if this were professional work, then I would want it to be truer to the film version.  The apparent bend of the hammer's neck over the wrench isn't nearly as noticeable in person; I think it may be largely a result of the lighting here.  White metal is difficult to photograph under bright sunlight, as it glares a lot, obscuring details, so I waited until I had time to take photos when it was cloudy out.  The pin was actually finished last Friday.

With the poured solder sitting in the mold, I blasted the torch over it to make sure it was still liquid, then put a common jewelry pin in the back and tried to drag some solder on top of it with the tip of a piece of thin steel rod.  As a result, the back is pretty rough in texture.  It's probably not a very secure attachment, but as the uses this pin is going to be put through are not high-stress, it should be good enough.

I tried to clean up some of the flashing and smooth the surfaces with a fine file, then buffed the entire front with a carbon steel Dremel brush.

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