Blog - Martin Pierce

pattern making for lost wax casting

Katydid Sculpture Takes Shape

The Katydid, sometimes called a green bush cricket or long horned grasshopper is a family of insects with 8,000 species. In California we see both the greater and lesser angle-winged species which were  reference points for Martin Pierce’s latest addition to his insect collection of  sculptures. The actual shape of his new piece though owes more of it’s design to the Mediterranean species but even this variety was adapted for stylistic and practical reasons  and made with wider wings.

 For those interested in the name Katydid it comes from the Greek word “tettix” meaning small cicada. Wikipedia enlightened this writer to the onomatopoeic  use of “ tettix” which when repeated makes a sound similar to one made by the Katydid when rubbing it’s wings together. Interestingly, the word Katydid  is also onomatopoeic as when repeated  “kat-y-did “imitates the stridulation of this insect.

When complete the Katydid will be considerably larger than other members of this species at a substantial 11” high by 16”long.

The progress photos shown here are provided courtesy of Maria Ramirez-Adams a fine art photographer and film maker.

 Having decided on the shape of the katydid, Martin enlarged his sketch and drew it as a scaled profile on vellum. The profile was then redrawn on thicker paper but as 6 separate body parts.

The profiles were used as patterns and each body section was crudely cut from solid basswood. Once cut the sections were carved with a variety of wood cutting chisels.

The 2 wings were cut from 1/8” plywood and were soaked in water to make them supple so they be could be twisted and bent around the thorax. Once the correct shape was formed, the wings were clamped and glued at the narrow thorax end and will be used to create a complex 3 part mold. The 2 wings were carved as a unit with a protective brace to prevent their fragile form from breaking. The outer main leaf veins were first carved and then the smaller veins were drawn and carved.

Custom door hardware - an index of posts on the process

Over the years of writing my blog I have often described the process from designing to casting door hardware using the lost wax method but have not until now felt it necessary to index  these posts.

The posts are broken down into 5 areas that describe the process from inception to end product. If you have limited reading time there is one piece that covers most of the stages that was was posted on June 21st 2017.

For details on the different stages please read on.

STAGE 1 - Design

These posts follow the creative process from the initial sketch to more detailed drawings that show the piece from different perspectives. They explain how the technical aspects of lost wax casting as well as the functional requirements of door hardware impact the design and result in modifications to the original concept.

https://www.martinpierce.com/blog/dragon-and-netsuke-door-knobs

https://www.martinpierce.com/blog/custom-designed-door-hardware-some-common-misunderstandings

https://www.martinpierce.com/blog/early-designs-for-a-new-entry-door-pull

https://www.martinpierce.com/blog/candlesticks-new-designs

https://www.martinpierce.com/blog/new-morphic-door-pull-one-size-does-not-fit-all

Stage 1 - detailed drawing from 2 perspectives Stage 2 - rough carving of pattern later refined

STAGE 2 – Pattern making

Lost wax casting requires an  original pattern or sculpture to be created. We create our patterns by sculpting  in a hard wood, blue wax or high-density foam. Our method is reductive and rarely makes use of 3D printing and we explain why in these posts.

https://www.martinpierce.com/blog/bumble-bee-cabinet-knob

https://www.martinpierce.com/blog/dog-door-knobs

https://www.martinpierce.com/blog/new-carp-fish-door-pull

https://www.martinpierce.com/blog/why-research-and-development-costs-for-custom-hardware-is-expensive-part-2

https://www.martinpierce.com/blog/3d-printing-as-useful-tool-in-casting-custom-door-handles

STAGE 3 - Mold making, gates and sprues

A mold of the pattern is made. The number of molds needed for one design depends on the complexity of the design and in assessing how the molten bronze will flow. The pattern is fitted with one central sprue and several gates that attach to the sprue and the edge of the pattern. A mold (s) is then  made of the pattern with the sprue and gates attached.

https://www.martinpierce.com/blog/how-to-make-a-simple-mold-for-lost-wax-casting

https://www.martinpierce.com/blog/how-to-cast-bronze-butteflies-good-and-bad-runners-and-gates

STAGE 4 – Wax replicas and shelling

The lost wax method requires a wax replica to be made for all the component parts needed to make one piece. The Hedgerow door lever for example require 4 waxes to be made; one for the escutcheon, one for the lever, 2 for the tree canopy. The waxes are then dipped in a silicone slurry that when hardened forms a shell that encases the wax. An auto-clave is used to remove the wax (lost wax)  and the hollow shell is ready to receive molten metal.

https://www.martinpierce.com/blog/wine-cellar-door-handles-and-shell-casting

https://www.martinpierce.com/blog/using-wax-facsimiles-to-create-bronze-door-handles

 https://www.martinpierce.com/blog/hawaiian-theme-door-handle

https://www.martinpierce.com/blog/creating-a-custom-appliance-pull-using-the-lost-wax-process-the-wax-stage

 https://www.martinpierce.com/blog/limited-edition-door-handles

Wax replicas ready to be shelled