Thursday, January 26, 2017

More Pewter!

So I'm not ACTUALLY looking to specialize in this stuff, but I can knock out a wax master quickly, mold making is an interesting exercise in geometry and materials science, and being the master of molten metal is just FUN.

Since my last post, I revisited my hnefatafl pieces in travel-sized pewter, did site tokens for our Yule event, a step-up baronial token for some friends, and a principality award.  ...  Oops, my last pewter post was further back than I thought. I've ALSO done a populace badge for a neighbor kingdom and MoD medallion in soapstone, and I'm currently working on a token for the new Princess, plus a few designs for pin heads.  Future projects I have in my head but haven't started yet include-but-are-not-limited-to two more populace badges, a consort token, more jewelery and a few different awards.

But for real, though. I'm not a pewterer.


Oldest undocumented project first, I'm going to talk about the soapstone populace badge. Soapstone is pretty spiffy stuff-you don't need a release agent, it's easy to carve, and its thermal properties means it just doesn't care about having 500 degree F metal poured in it hundreds of times.  The downsides are that you need to carve a negative rather than a positive, and the fact that soapstone comes in a wide variety of quality. The stash I currently have is more stove grade than sculptural, which means SURPRISE, this little bit is three times harder than the bit right over there!

So anyways, step one was finding a bit of stone with an even grain.  Once I had that, it was time to smooth both faces.  I've found that a back and forth motion is exactly wrong, as I tend to rock in the motion a bit and end up with a curve on the stone face.  What DOES work is wax on, wax off, on a sheet of 60 grit sandpaper or in a pinch, a cement paver. The next bit of preparation was not really necessary for the finished product I had in mind, but I wanted to show off a bit of technique.  
The dots and holes in the corners are called registration keys, and they make sure the two stones fit together perfectly, but only in one configuration.  While I had the two pieces clamped together, I drilled two holes through Side A, and just a smidge into Side B.  Then I enlarged the hole on Side B, re-clamped the two pieces together, and poured some pewter into the holes made in Side A.  This step would be more important if I were going to have a design on both sides of the eventual piece - I'll talk more about two-part molds when we get to the Snowy Owl.

Now to the actual design! Carving negatives makes me grumpy, because I'm not as good at it as carving positives.  Sculpey, modelling clay or silly putty helps here, so you can see what the positive is going to look like, as long as you remember that there's some mirroring going on.  At the point of the above photo, I was pretty happy with the design, so it was time to think about how to get metal INTO the mold, and then also how the cast was going to be attached to a person.  I decided to go from sprue to integral attachment point and from that to the medallion itself.  This mostly worked, but in test pours, I wasn't able to get the medallion part filled - the metal was cooling too much as it went through the more restricted part between the sprue and main body.  I ended up having to file away a bit of the necklace hole part - instead of being able to pop it out of the mold and immediately string it on a necklace, there's instead a dimple which at least makes drilling the hole easier.


 



Next up! Hnefatafl pieces!  I pretty much completely reused my design from the wooden set, although I did redo my chief piece.  In the game, that is the most important piece, but can not participate in captures.  So how to display a person of importance who can not fight?  In the Anglo-Saxon era, the answer is BEARDS! (http://marcus.group.shef.ac.uk/bigger-is-better-anglo-saxons-and-their-beards/ it's a fun read, go check it out! Okay, fine, here's a TL;DR)

On the other hand, the beard was a very personal and visible symbol of a man’s honour and pride. Men were known to grab their beards as a testament of honesty. The thirteenth- to fifteenth-century Chronicle of Evesham Abbey records the story, during the reign of Æthelred, of peasant who grabbed his beard while swearing a false oath on relics in a land debate with the abbey. The dishonest gesture caused his beard to fall off.

The Bayeux Tapestry, made by the Norman people, also specifically depict well regarded kings (Edward the Confessor) as having impressive beards, so I think it stands to reason that this was a visual shorthand that spanned multiple cultures.  With that introduction, it's time for our closeup!
 

and now for the other two designs.


The mold making was the same technique as my capricorns, with a slight twist.  I used 10 ga wire as my sprue, Why? Because of the Ballinderry Board.  

Those holes were put there for a reason, namely pegs in the gaming pieces. Which makes sense, flat space would be at a bit of a premium in a crowded house.  So, sprues were designed to do double duty as pegs.  I'm not going to lie, it also saved me some sanding, and I appreciated that!








Half done!  My next project was the snowy owl, which is given out as a principality-level award for excellence in crafting.  I was very proud of this carve, but it's a bit more intricate than anything I've cast to date.


I couldn't just do a one-part mold around it and blindly cut my way in, I'd end up with a frustrating mess. So, a two part mold.  I sunk the back half of the owl in modeling clay and poured my silicone over the top half of the owl.  A few days later, I turned it upside down and peeled out the clay, leaving the back side of my wax exposed.  Because the silicone will fuse to itself if I just poured a new batch over, I had to come up with a mold resist.  Store bought stuff from micheals sadly did not work, and I had to go back to the drawing board.  My second try was paste wax thinned with white gas, which worked perfectly (as a side note, white gas also causes tiny plastic cups to lose their structure, so mix this in glass and also probably don't leave the mixture in the plastic cup in your kitchen overnight. Just saying).



You can still see the thinnest skin of paste wax leaving a bit of white residue, but that all worked itself off pretty quickly.  And here's the other two masters and molds! Krampus for our Yule event, and the pair of C's for a barony token.  As you can see, the waxes don't have sprues or connection points attached, but they exist in the mold - I found it was much easier to make that in modeling clay, rather than melt bits back onto the wax.

A busy afternoon of casting later, and I had a dozen owls, seventy-five Krampuses (Krampii?) and twenty baronial tokens.  I have also found that Aluminium Blacking from the sporting goods store does have the right kind of acid to turn tin black. Yay!  A quick bath in that, and then some 000 steel wool to clean up and voila!






































1 comment:

  1. Wow!! I'm exhausted just reading about all that great work. :)

    ReplyDelete