Wacom Pen Holder Hand AKA Making a Plaster Cast of Your Hand

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About: I'm a (mostly) pet photographer in Melbourne, Australia, and a DIY junkie. Particularly when it's photography related.

This project started off having nothing at all to do with a Wacom tablet, rather a solution to the problem of a couple of old mannequins with not enough hands between them.

It may have been easier to source a hand from another mannequin but a) a lazy online search yielded nothing helpful, b) this is Australia and useful things can be hard to find and c) why make things simple when it can be over complicated!

And so I decided to create a new left hand for the male mannequin using my own as a model. I'm female, but my hands are big enough to pass for a man's.

Researching the creation of plaster cast hands led me to using alginate as the casting material as it's skin (and mouth!) friendly, flexible enough to allow your hand to be removed once set and can be broken off afterwards, liberating the plaster object. Plus it's minty.

The plaster choice was merely due to there being a harder option than normal plaster at the shop and I thought why not. Normal plaster should work fine though, provided it's mixed right and you're gentle with it.

Supplies:

  • 2 x 140mm plastic plant pots
  • Hot glue gun & glue 450gm
  • Alignate impression material - any brand would do, I used Chromax as it's the first I found and it's handy (no pun intended) that the colour changes when it's set.
  • ~1kg Plaster of Paris - I used Hydrostone TB High Compression Gypsum
  • Scissors to trim alginate
  • Sandpaper for plaster cleanup

Optional:

  • Bolt to screw into mannequin arm (walking around a hardware store with a mannequin arm leads to strange looks from others)
  • Kitchen string
  • Kid's plastic spade to tie the bolt to and hold it in place while the plaster sets
  • Dremel for shaving off the rough bits of plaster

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Step 1: Container to Hold the Alginate

I hit the hardware store and the best option for something disposable, narrow and deep was 2 plastic pot plants hot glued together by their rims and the drain holes glued closed on one. I cut the bottom off the other pot to make an open end.

Any container the right size will do the trick really, and you may not have to cut it off to release the mould if it's the right shape.

Step 2: Add Alginate to the Pots

Add water in the ratios specified on the packaging and spatulate for the time specified. My alginate started off pink to indicate it wasn't set, turning blue when set. This happened in 2 minutes so you don't have time to waste!

The packet I bought was *just* enough to cover my hand, ending at the start of my wrist. For larger hands or containers you'd need more.

Ignore any instructions related to putting the alginate in anyone's mouth.

Put your hand in the mixed alginate and keep it as still as you can. I curled my fingers around slightly as the mannequin needed to be holding something. Plus there wasn't enough alginate to hold them straight out.

I didn't take any photos of this part as I'd made a mess and didn't want to involve my phone in it.

Step 3: Removing Your Hand and Getting the Plaster Going

Removing your hand is surprisingly easy, even if at first it feels like it's trapped in there forever. The alginate has a bit of give in it so you just need to wiggle it free.

Mix your plaster as per instructions, you'll have to guesstimate the amount needed unfortunately. But it's cheap so overestimating is fine. Pay attention to safety instructions on the container as it's not great to inhale the dust, I use a respirator for these things, but that is likely overkill. Pour mixed plaster into the mould as desired.

I needed a bolt in the end of my hand so it could be screwed onto the mannequin so used a kid's plastic spade and some string to hang it in the plaster until it set. If you do this make sure it's deep in the plaster so there's no chance of it breaking out by accident. Also make sure it's not going to be sticking out the side of the hand anywhere.

Let the plaster set well, you really don't want the fingers breaking off.

Step 4: Set That Hand Free!

This part is fun, and kinda creepy. The alginate allows for very high resolution casting so you'll see a heap of detail. It's also weird because it's recognisably your own hand, but not and it's not attached to you and something isn't right.

Break the chunks of alginate off the hand, there is no point trying to save the mould as it won't release the plaster easily and will degrade over time anyway.

Enjoy the minty fresh smell.

Step 5: Cleaning Up the Plaster

My hand had a bit of extra plaster at the top so I used a Dremel to cut it away and then sanded it lightly. Be very careful with sanding as the plaster will still be quite soft and you can lose a lot of detail very quickly.

I checked the alignment with the mannequin arm at this point and was very pleased.

Step 6: Paint Your Creation

Crack out whatever you're using to paint - I used a can of spray paint for a nice, smooth finish, but anything would do the trick.

Do not, under any circumstance, allow the hand to fall off your work bench. It will break and your brain will have a small spasm over the weirdness of the dismembered fingers. Although it was funny that it was flipping the bird.

Glue and painter's tape to hold the fingers in place fixed it, but it's obvious where the breaks were.

Step 7: Finished Product

Having fulfilled its purpose for a photoshoot, the hand now needed a use other than looking creepy on the mantel piece.

And this is where the Wacom pen holder job came in. If you were designing the hand just for this purpose you could pose it differently to make the fingers closer to the pen, making it a more useful pen holder.

Mine is really only ornamental as it does need the proper pen holder under the hand to keep it in place. Still, it's a cool looking desk ornament and I was happy to be able to repurpose it so easily.

The mannequins will also have another life, they've been sanded back and are having their cracks and holes filled with epoxy (which wasn't necessary for the photo shoot) and will be repainted something yet to be decided.

I hope you enjoyed this somewhat meandering Instructable :)

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    16 Discussions

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    bpark1000

    Tip 19 days ago

    Dry the plaster COMPLETELY before attempting to paint. You can put it in an over set at 120F for several hours. The plaster will get stronger and the paint won't peel off in time.
    When releasing the hand from the alginate, use a straightened paper clip to poke holes from the bottom into the tip of each finger. This will allow air entry.

    2 replies
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    huplescatbpark1000

    Reply 14 days ago

    This is a great tip, thanks! Is there a point at which plaster will crack in the heat? Will any air bubbles cause a problem?

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    bpark1000huplescat

    Reply 14 days ago

    Yes, if you heat it too hot, you will essentially reverse the plaster's setting and turn it back into a powder (this is referred to as "calcine"), but this won't happen at 120F. Air bubbles won't be a problem at this low temperature. The secret is to have it heated to 120F and with circulating air so the water vapor can escape. Plaster's strength more then doubles when it is properly dried. In addition, trapped water inside the plaster will lift off paint as it attempts to escape from inside. See this link to US Gypsum recommended drying scheme. (You don't need to get this fancy, but keep the process in mind, and allowing a lot of time for drying will make up for lack of fanciness).

    http://www.douglasandsturgess.com/HowTo/Drying-plaster-Howto.pdf

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    Zaacharia

    Question 17 days ago

    Hah! In stead of making the hand out of plaster, I can make it out of wax then, using the lost wax method, cast it in glass.
    Also, many years ago I used alginate to make a life mask; the first one came out full size; then the mold shrunk and I made a mini-me life mask. Since my kiln is only 8x8x8 I can't cast my life mask in glass.

    All you mold makers, if you can make a mold of it, you can cast it in glass - provided you have the heat.

    1 answer
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    charlessenf-gm

    18 days ago

    I enjoyed this instructable. Years ago I had a female torso mannequin I kept in the front seat of my van - I did buy her a nice blonde wig. Talk about photo ops! - having a camera catch the expressions of passers by . . . Hmm replace one of her eyes with a camera . . .or a small camera on he right ear.

    1 reply
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    huplescatcharlessenf-gm

    Reply 14 days ago

    I have been wanting to do this, but hesitate knowing that the kids would probably refuse to get in the car if there was a mannequin on board and I was giggling maniacally over it.

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    I assume the alginate is fairly waterproof once set?

    To estimate the amount if plaster needed:

    Fill your mould with water to the level you want the plaster.
    Pour the water into a marked container of some sort (measuring cup, pitcher etc).

    Heck, maybe just use the water that came out to mix your plaster.

    1 reply
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    I would assume it's waterproof given it's made for dental applications it'd have to be :) Some of the colour from the alginate did transfer to the plaster, but I think that was just the dye itself.

    It would have made sense to measure the amount needed a little more exactly, but I often just go with the flow and wing it. It *usually* works out fine...

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    tomascco

    19 days ago

    Nicely done! I'm wondering if an armature would be overkill?

    1 reply
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    charlessenf-gm

    Tip 18 days ago

    "guesstimate the amount needed"
    Fill a vessel with water (to the brim). Stick your hand into the container, catch the spill over in another container. Pour the 'spill over' into a measuring cup (or some such) and you will have the volume (of plaster) required. Its fizzicks!

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    seamster

    4 weeks ago

    Well done! I let out a gasp when I saw the broken fingers. We've all been there - after so much work and something goes wrong! Nice to see that it was an easy enough fix though, and the finished hand cast looks great! : )

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    huplescatseamster

    Reply 4 weeks ago

    Ugh yes, my heart sank when I saw it on the ground! But I guess part of making things is rolling with the disasters :)

    And thanks!

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    M3G

    4 weeks ago

    Nice work! I love your writing style, this was an entertaining read.

    1 reply