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Acrylic GeoCoins - how to make proxies


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Hello again, back with another method of making proxies for missing or collectible TB's. This time, the focus is on a GeoCoin, with no hitch hiker.


For this method, the main cost was the purchase of some acrylic (plastic) coin capsules used for storing collectable coins. I put "plastic" in there as I'm not certain that the ones I got were actual acrylic or some different type of plastic - but acrylic is preferred as it is easy to seal shut with a little bit of acetone. I bought a set of ten 40mm (1.57") capsules off eBay, so they could be made of compressed rice for all I know.


Once designed, the first step is to print and cut out the inserts.




If you want to use this method, check the sizes of the capsules you use. For most, one side will be slightly larger than the other. You can either print to suit, or print two the same size and trim down the smaller one - you just need to account for that in the design and leave enough border to allow for the smaller size. Once cut out, the faces are glued to the inside of the two halves. Note that I included in the print a "band" of solid colour. This is to use as inserts around the edges and hide the centre of the coin.




The edges can be a little bit tricky, my bands of colour where much larger than they needed to be, so I cut them down the centre so I'd have two goes at it if I made a mistake.




The glue is allowed to dry, then any protruding paper is trimmed off with a sharp blade.




At this stage, the two halves could be glued together and the GeoCoin would be "complete". Personally, I didn't like the feel of a very light plastic coin, and worried that the hollow interior would allow the coin to be damaged too easily if some weight or force was placed on top of it. I applied more glue to the inside face of all the paper inserts in order to seal them, then grabbed a lead fishing sinker and hammered it flat into a coin-ish shape.




(Apologies for the blurry photo, this is the best one I have.) The sinker on the right is the original shape, the one on the left is the flattened one. I used the underside of a metal stand for the hammering, due to lead being Something You Don't Play With. (If you're not sure why this is, Google "lead poisoning".) If I had my way, I'd rather have created a mold, melted the lead down and poured it into the exact size / shape I needed. However this would have required the purchase of equipment I didn't have, and added to the cost. If you're going this route: tip is to use lots and lots of little impacts to get the desired shape rather than attempting to smush down with a few hits. Lead is very malleable, but sudden impacts tend to make it crumble, which is a Bad Thing.


A better option is to use a thick metal washer, an actual coin or lots of teeny tiny ball bearings. I didn't have any of these items in a suitable size, and I did have some spare sinkers which I wasn't going to use again. If you're not a fan of lead, there are alternatives available.


For strength, and to seal the lead in, the smaller half had some 5-minute epoxy poured in and the flattened sinker placed in. Once dry, more epoxy was placed over the top to make sure it was all sealed in and make it safe to be sent out into the public.




Once that was nice and dry, more epoxy was put on top, the two halves put together and then squeezed tight to force the excess epoxy out between the seams and seal everything up nice and tight. It did make a bit of a mess, but I'm 99.9% confident that no water will reach the paper, and no lead will reach another persons hands. (I also added a note on the TB page about the internal lead content in case it ever breaks open).




And done! A nice, clean GeoCoin, weighing in at a feels-nice-in-the-hand 34g (approx 1.2 ounces), solid construction that shouldn't break in a cache or someone's bag and with nice legible printing for the design, text and TB code. Total out of pocket expenses were about $1.50 each (mostly for the capsules, the printing was negligible, the sinkers were old spares and the epoxy I had left over from another project; not counting the cost of a TB for the code). Time was about an hours' worth of actual labour over about two weeks while allowing plenty of time for glues / epoxy to dry. If I make more, I don't think I'll use the lead (I don't have any more sinkers, and there's the ever present concern about it breaking open), but I'm happy with these two.


We'll see how far they travel on the winds of fate...

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