Well, I just went through our coin collection (saving up for years - 1p 2p 5p in a bottle) had 760g of pure copper coins, 1p and 2p. Easily done with a magnet 
Well just got rhe coins soldered together!
A lot of heat and cleaning with acetone first did the trick!
Would you mind posting a few pictures while you are going along with the mod?
The other day I was thinking about going the same route with my S2+.
+1 here 
Although I have a pill and a spacer from kiriba-ru (hence my post above) I will probably need a 3rd spacer but I’m having difficulties to get a “proper” pre-made material. So maybe this method can help a bit!
How many MM thick is the spacer?
Edit this would depend on the optics being used.
regular s2+ spacer is 6mm thick.
I tried to make it with 2 coins first which is 4,5mm kd triple with included optic! Seems like there is no 'play" space seems nice and tight! lol! 3 coins is roughly 6mm fits fine still! Should I use the 6mm eventho 4,5mm works too?
For pilled flashlights you can make spacers not so precision because you can compensate wrong height just by screwing/unscrewing pill.
I made different heights with coins depending on the light I wanted to put this in. protected vs. unprotected battery.
One S2+ has 8+mm spacer for shorter, really tight batteries. Another only 5mm because I sanded away a bit too much.
Also depends on the springs you are using, which driver, what tail cap, etc
I used 10 cent euro coins!
Ok pics coming soon, too tired now for that lol!
Anyways 3 coins is needed for proper fit! I sanded them smooth and solder them together aswell as solder the top of the pill, where it's about 1mm recessed, flush and sanded it smooth! Now the top of the pill is smooth like a hotplate!
I have done two spacers with coins and it all went well, but then I thankfully found kiriba-ru and his selection!
While making coin spacers is a ton of fun (“I did it on my own”) - you would also have to account for sanding time, soldering, drilling the whole thing and then cleaning. All in all, it is fun to do and a great workout but an actual copper spacer for a few dollars is probably the more economic solution.
Coins however also allow to alter the size of the coin and make different spacers easily - you could combine 16, 20, 15, 20 (and so on) and it looks like more like a heatsink rather than a spacer.
Yea but some time you want some thing done now not in a week or two. Or is that only me? lol
I agree, if someone is pressed for time or has enough free time on their hands… it is the way to go!
yeah finished them just now , lots of sanding, soldering, cleaning and drilling but fun! However I never sanded them down for soldering, only the contact surfice to pillband led board! Should I sand the solder surfice aswell? And redo them? I mean the coins sit perfectly on top of eachother but dont know? Maybe the solder filled the gaps lol?
I would leave it and see how it handles the heat.
I did this a while back with some old pennies. I sanded them all flat first, it was a pain in the ass but I was actually able to turn the stack on the lathe afterward.
Yeah I filled the top of the pill with solder and sanded it smooth aswell to get a bigger surfice for the spacer to sit on and aid cooling aswelI! Hope solder works well for heat dissapation? The coins were a bit uneven but I think it will be fine, migh just aswell try it! I soldered the recessed top of the pill and holes shut!
The Euro coins that look like copper (1 cent, 2 cents and 5 cents) are not copper but an alloy with a lot of iron (they stick to magnets).
I wouldn’t advise anyone to use them as heat sinks.
The coin is 10cent euro "nordic gold mix" which is 89% copper, 5% aluminium, 5% zink and 1% thin, so should be pretty good right?