NAME: Sofia Gans
DATE AND TIME: March 2, 2015, 10:30AM
LOCATION: 260 Chandler
SUBJECT:
Molding with a cuttlefish bone
Recipe:
091r
<title id=”p091r_a2”>Mouler en os de seiche</title>
<ab id=”p091r_b2a”>Garde bien de ne les tenir en lieu humide car ilz sont<lb/>
fort subgects a shumecter Si ta medaille est petite couppe los<lb/>
en deulx puys unis le avec un costeau Et sur une tuile a crochet<lb/>
bien seiche & bien unie & couverte de charbon de saule pulverise<lb/>
frotte & unis les moicties des os Ainsy ilz sabreuvent de ce<lb/>
charbon de saule qui les faict bien despouiller & garde de rien<lb/>
enlever Puys sur un contre os cest a dire un lopin de<lb/>
brique unye de la grandeur de ton os pose ta medaille & puys<lb/>
sur icelle pose los & presse bien avecq quelque aultre piece de<lb/>
la grandeur par dessus Et pour la seconde fois moule le<lb/>
mays plustost ponce dessus du charbon de saule & soufle<lb/>
legerement puys presse co{mm}e au paravant Et il viendra net<lb/>
Si cest pour un manche de cuiller il fault deulx osentiers<lb/>
Tout ouvrage gecte est aigre & subgect a rompre pourceque<lb/>
le metal se dilate au gect & se reserre & condense au marteau<lb/>
Cest pourquoy il fault resuivre la chose gectee avec le ciselet<lb/>
& en ceste sorte le metal se resserre Laisse le ainsy escrouir<lb/>
Si la piece a mouler est de grand relief trasse premierem[{ent}] le<lb/>
moule & le cane avecq un trancheplume pour faire voye a la<lb/>
medaille & puys moule Et si la medaille est a deulx envers</ab>
<ab id=”p091r_b2b”>co{mm}e les deulx os sont joincts co couppe les tout aultour bien uniment<lb/>
& fais des coches e aultour en divers endroicts qui traversent<lb/>
sur la joincture des deulx os affin de recognoistre bien lendroit<lb/>
de leur premiere joincture Ou bien avecq de petites pointes de<lb/>
bois traverse les ou ma enduicts les joinctures avecq de lardille<lb/>
& fais seicher Presse entre les des mains joinctes entre<lb/>
les deulx genoux & non pas avecq presse pourceque los<lb/>
sesclateroit Moule aussy a laise & a deulx ou trois fois<lb/>
jusques a ce que tu voyes quil soict bien acache & bien<lb/>
empraint et a chasque fois plustost que remectre la piece<lb/>
ponce avecq du charbon de saule Car il faict bien despouiller<lb/>
Quand tu as gecte frotte dhuile & depouldre de charbon<lb/>
de saule & avecq des broisses la medaille pour la<lb/>
ternir Garde que ta medaille ne soit point grasse ne<lb/>
huilee quand tu mouleras en os de seiche Quand tu as<lb/>
gecte laisse refroidir plustost den retirer la medaille<lb/>
car quand on la retire chaulde elle emporte de los Et<lb/>
gecte mediocrement chault ce que tu cognoistras quand<lb/>
los ne change presque bien point sa blancheur Mays<lb/>
quand il est trop chault il roussist fort los La<lb/>
proportion de plomb & estaim est dun aultant que daultre<lb/>
Si la piece est difficile a venir & de plusieurs pieces<lb/>
fais le gect fourcheu de trois ou quatre rayes et<lb/>
fais & conduicts ces rayeures a lendroit des parties<lb/>
plus espesses Fais aussy des rays aultour de la<lb/>
medaille co{mm}e au droit des testes car cela attire le<lb/>
metal & abreuve mieulx la figure Remue un peu ton<lb/>
chassis quand tu as gecte Et ainsy tu feras fort net<lb/>
plusieurs gects Lestain trop chault brusle los qui<lb/>
se corrompt Estant aussy retire du mo chault du moule<lb/>
il est dangereulx a rompre</ab>
<title id=”p091r_a2”>Molding with cuttlefish bone</title>
<ab id=”p091r_b2a”>Pay attention to keep the bones in a dry place, because they are very prone to dampness. If you have a small medal, divide the bone into two pieces, then smooth the two parts with a knife. And on a dry, smooth rooftile [that has been] pulverized with willow charcoal, rub and polish the two half bones. In this way, the bones soak up the willow charcoal so that the bones will come off cleanly from the cast, and will not stick to it. Then on a fake bone, that is to say a bit of smooth brick of the same width as your bone, place your medal. And then on the medal, put your bone and press it firmly with another stone of the same size. And for a second time, mold it, and instead smooth over the top with willow charcoal and blow slowly, then press as before, and it will cast neatly. If it is for a spoon handle, you need two whole bones. Any work that is cast is brittle and prone to breaking, because the metal swells when cast, and contracts and condenses when hammered. That is why you must retrace with a chisel the cast object and in this way the metal will contract again and let it escrouir. If the piece you have to cast is in high relief, first trace the mold and the hollow with a penknife, to make a clear path for the medal and then cast it. And if the medal has two sides</ab>
<ab id=”p091r_b2b”>Because the two bones are joined, cut around them with precision, and make notches in different places which cross through where the two bones are joined, so as to recognize the place where they were first joined. Or with little shards of wood, you can also pierce the bones, or coat the joints with clay, and leave it to dry. Compress it with your two hands in between your knees; and do not use a [normal] press, otherwise the bones will break. Mold at your leisure two or three times, until you can see that it has [the design] come up and is well imprinted. And on each occasion rather than putting the piece straight back in the mold, smooth with willow charcoal because it helps it to come out easily. Once you have cast, rub your medal with oil and willow charcoal with a brush, to make it dull. Take care that your medal is not greasy or oily when you cast it in cuttlefish bone. Once you have cast, leave it to cool rather than taking the medal out straight away, because when you take it out hot, some bone will come away with the medal. Cast at medium heat, which you will recognize because the bone should stay almost white. But when it is too hot, the bone becomes brown. The proportion of lead and tin is equal, one to the other. If the piece is difficult to cast, and composed of various pieces, cast it with a forked pattern, of three or four grooves, and make these grooves where the metal is the thickest. Also make these grooves around the medal and directly on the head because this attracts the metal and will fill the figure best. Lift your boxmold a little, once you cast, and in this way you will be able to make several clean casts. Tin that is too hot burns the bone which becomes damaged. Moreover, having come out of the mold hot, it risks breaking.</ab>
Materials:
- 2 cuttlefish bones
- willow charcoal
- terra cotta plate
- object to be molded (first a high-relief necklace pendant, second, my engagement ring)
- tin/lead alloy (2 parts tin to 1 part lead)
- carving tools
Process:
Preparing the cuttlefish bones
- I put some crushed willow charcoal on a terra cotta plate, and then began rubbing the spongy side of the cuttlefish around on it.
- the surface immediately began to powder off. I continued until there was a wide, flat surface to cast on, tinted grey from the willow charcoal
- I repeated the same process for the other half
Impressing the object
- I took a fire brick and laid my necklace pendant on top of it.
- I placed one smoothed cuttlefish bone on top of the pendant, flat side down.
- I placed another fire brick on top of the cuttlefish bone and pressed down.
- I tried to press slowly and evenly.
- It was very difficult to get an impression, as the relief was so deep. I tried several times and, after a few presses, the cuttlefish mold cracked and I had to start over.
Starting over
- I smoothed two new cuttlefish bones and chose a different object to cast, my engagement ring.
Impressing the ring
- This time, I tried between my knees. I placed the ring between the two pieces of cuttlefish with their smoothed sides facing inwards. I carefully placed this sandwich between my knees and began to press. The ring began to slide into both sides of the mold. I could feel it catch. I had to readjust the placement a few times to try and get even pressure from me knee joint/thigh muscles. I continued to press slowly and evenly until the two sides came flush together and the ring was entirely enclosed in the mold.
- I opened the mold and pressed it together again a few times to ensure a very clean cast.
- I used the jeweler's saw to make notches on three different points around the sides that could be tied together to secure the mold once the ring was taken out.
- I sawed off the top part to allow a smooth entry area for the metal.
- I removed the ring.
Carving the gates and sprues
- I carved a large gate for the metal leading to the bottom of the ring. I then carved a small channel directly to the ring itself, and two others on either side to create a branch of three entry points for the metal.
- I then carved two vents leading off the side of the ring and out the top of the mold.
- I fitted both pieces back together and wound wire tightly through the notches.
Casting and final result
- I put a little clay at the bottom of my mold to prevent leakage that other students had experienced.
- Andrew heated and poured the tin/lead mixture and we left it to cool for a day.
- The final result was amazing!!! It was SO clear, picked up tons of detail with very little flashing. I didn't even need the clay at the base as the mold was tightly bound enough to contain the metal. I could have cleaned and finished the ring and had an amazing replica! Plus the mold remained totally intact and could likely have been used to cast from again.
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My mold bound up before casting |
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Mold and product post casting |
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Detail on the cast ring |
ASPECTS TO KEEP IN MIND WHEN MAKING FIELD NOTES
- note time
- note (changing) conditions in the room
- note temperature of ingredients to be processed (e.g. cold from fridge, room temperature etc.)
- document materials, equipment, and processes in writing and with photographs
- notes on ingredients and equipment (where did you get them? issues of authenticity)
- note precisely the scales and temperatures you used (please indicate how you interpreted imprecise recipe instruction)
- see also our informal template for recipe reconstructions