After lurking around here for a bit, I became obsessed with custom key caps. But since I never seem to be online when an artisan key cap sale goes live, I've decided to try my hand as creating some myself. My only issue starting out was that everyone seems a bit elusive with their molding process. There were some decent nuggets of information in sub forum however... enough to get me started in the right direction. Maybe.
Beware of over sized potato pics.
My starting key cap was a signature plastics DSA cap, since that's what I've become accustomed too. I wanted it a slightly smaller profile than what I've seen so far so I chose that over the OEM cap on the Poker II.
My sculpting material of choice is Apoxie Sculpt. After failing with carving wax I had to break down and buy this two part epoxy. The only down side for me was its' very long cure time... 24 hours. Since the design I was going after called for clean, hard lines, I had to wait for it to cure after each application... which was many. Creating my original this way took me forever.
It was inspired by a spartan helmet.
Next step was to create a two part silicone mold. I used Alumilite Quick Set silicone. I'm still experimenting with my mold techniques and sprue locations.
Currently using 5 sprues located on the bottom mold. One in each corner and the fifth one on the cherry mx stem. I can get a better pic of this if someone's interested. I have no idea if this is over kill, since this is the only bit of information I can't find disclosed throughout this forum.
Next is the resin. I used Alumilite white casting resin since it was the lowest viscosity, besides the translucent options. Since I have no pressure pot, clear resins aren't an option at this point. I also used Alumilite florescent Green as the pigment.
By using a 6 cc syringe I injected my resin into one of the sprue holes untill it flowed out of the remaining 4 sprues. My silicone mold was also preheated under a ceramic heat lamp(originally used for reptiles) before and after injecting the resin to assist in proper curing. You could use an oven but I thought that would be kind of wasteful for my small key cap.
This picture gives a better explanation of my sprue placement. The 5th sprue is not present. It broke off.
All of my efforts rewarded me with this. A flawless specimen. *excitement intensifies*
But then I was cursed with a streak of failure.
Reasons varied from incorrect resin mixture ratios to mixing resin too vigorously and introducing too much air into the mixture. Also my sprue locations and technique is suspect since I have no idea what I'm doing in that department. So far I have one perfect cast from one of my first attempts, no air bubbles or defects. I have since created several others with some very miniscule defects such as tiny bubbles on the underside of the key cap. These are acceptable for my Poker but I have yet to create another perfect specimen.
Money shot.
All in all I have about 60 dollars sunk into this little project. I'm continuing to experiment but this is where I'm at for the time being. I need to figure out some proper techniques and most likely lurk more threads covering the same topic.
As far as materials go, I am satisfied with the alumilite products that I've tried so far. Quality stuff. One material that I might need to swap out though is the white resin which seems to be a bit soft. It might be user error ratio wise, but I can't seem to get the casts as hard as the original abs keys. They're not quite gummy but they're definitely not rock hard either.
I will update upon further experimentation.
Bonus picture!
Thanks for the support guys.
Someone inboxed me for a more detailed explanation of my process. So I took more potato quality pictures.
I start off with my measuring cup and syringe. I dab some dye into the bottom of the empty cup. Then try my best to pour 2 CC of part A of the 2 part resin mix into the cup and stir *carefully*.
Then I pour in 2 CC of part B and stir. As soon as part B hits, the mixture is chemically activated and you need to stir swiftly but introduce as little air as possible. I can't stress that last part enough since I'm not working with a pressure pot.
Before I mix the resin together I collect the mold from my makeshift oven. When the mixture is complete, I take it into the syringe and inject it into the corner sprue of the preheated mold until excess resin flows from the 4 other sprues. The mold is held together with electrical tape. It then goes back under the heat lamp for 5 minutes.
In this picture you can see clearly where the sprues are located. I drilled these holes from the other side(the inside out) after I created the 2 part silicone mold because this was easier for me than trying to attach 5 tooth picks to my original and then silicone mold that.
When it's ready, it looks like this. I trim off the top excess puddle before separating the mold which lets the material in the sprues pull though the silicone easily, if cured correctly.
This was a 99.5% successful cast of a minty green spartan. There's a miniscule bubble in one of the bottom corners.
I'm updating again with news that I've worn out my silicone mold. Bits of it has broken off inside one of the cast resin caps. They only have a small amount of uses, it seems. Too bad silicone takes so long to cure
One thing I wish I had to improve my success rate would be a sensitive gram scale to measure my resin mixture with. At the moment I'm trying to eyeball 50-50 volume ratios which is tricky when your total volume only needs to be like 4 CC's.... when I add more dye to the mixture it gets even more tricky. More than 50% of my casts turn out way too soft due to inaccurate measuring.
