This is the story of how a chain bangle became the inspiration for Martin Pierce’s door handle that was commissioned for the prestigious Post Oak Hotel in downtown Houston. A sequel will be released soon showing how the entry handles were developed for the public areas of the same project but here we focus on the shower door and French door pulls.
The Gensler team in the Houston office sent Martin Pierce a picture of a gold chain bracelet to give him a sense of the texture and asked him to come up with 2 concept designs. The handle needed to be 12” in height, round in shape, comfortable to grip and made in a durable alloy. Before he could submit a concept drawing, he first had to assess how to create both the pattern and the subsequent steel castings. This aspect of commercial design is as he puts it “always a chicken versus egg issue as you need to sketch and modify your sketch at the same time that that you develop and test different maquettes of the piece”. Martin interpreted the metal chain as rope or braid and sketched this while he created physical braids from rubber coated electrical wire. Since the handle design was round he used a ¾” wooden dowel for the core of the maquette and applied the wire braids to the surface in a tight formation.
For the alternative design he loosely interpreted the bangle as a chain of vertebrae or building blocks which he named “Segment”.
These drawings became the basis for the first patterns, molds and ultimately the prototype handles which were cast in stainless steel. For the braid handle he made 2 alternative ends, a soft rounded crown and a more contemporary flat version and it was the latter that went into full production. I asked Pierce for a phase by phase account of the process from inception to installation and this is what follows.
Design Process – Free Hand drawings drawn to scale showing the 2 choices for braid and the alternative “Segment” were prepared and submitted to Gensler for their review and client’s approval. The more contemporary braid handle and the Segment were approved and prototypes were ordered for the mock-up room. For those unfamiliar with the term, the mock-up room is where alternative samples of fabric, wall covering, furniture and hardware are assembled for review by the project owner.
Pattern making –
To create the Braid pattern Pierce wove 3 stands of electrical wire into a tight braid which he used to create a simple mold so that the braid could be reproduced in resin. Seven sections of resin braid were made and individually fitted to the surface of a wooden dowel. The pattern was then tooled by hand to remove imperfections and to fill any small voids. The round ends were turned on a wood lathe. The Segment handle was assembled from different diameter dowels that Pierce cut at varying angles and then jointed to form a continuous length.
Mold making –
Since Pierce’s company would hopefully be making over 1,000 handles, he needed to create a high-performance mold capable of making uniform waxes. This was created using a high density heavy epoxy resin for the outer box section of the mold with the inner section in latex rubber. The epoxy according to Pierce creates “an extremely heavy pressure resistant box and one that can be made in 2 sections that are keyed together with notches that align the halves and by metal bolts that pull the box tightly together. The interior of the mold is made in a pliable latex that is brushed onto the detailed braid section of the pattern to create a latex impression of the braid. “
Casting Process –
Red waxes were made by injecting wax at a temperature of 130° and at 250 psi into the bolted epoxy mold. The wax replicas were then linked together with wax sprues in 5-unit gangs and then repeatedly dipped into a ceramic slurry before being left to dry in a temperature and humidity-controlled room. Once dry the slurry formed a casing or shell around the waxes and these were placed in a heated autoclave which melted the wax out and left behind a hollow shell ready to receive molten steel. This process is at the heart of the “lost wax method of casting”Chasing the Castings –
Next Pierce explained how the raw castings are then ground and tooled by metal chisels to remove extraneous metal from the casting.” The casting will have metal gates and sprues that need to be ground off and there may be small imperfections caused by gas bubbles that will need to be removed with fine metal chisels and dremels and this process is often referred to as metal chasing.”
As some of the handles were to be mounted on one side of a door the end posts for these needed to be drilled and tapped so that a bolt could be screwed in from the inside of the door. Most of the handles were to be mounted as pairs on both sides of a door so only the inside handle was drilled and tapped. The post ends for the exterior handle were drilled not tapped but two additional small holes were tapped and drilled for “fastener” screws. The bolts were then tightly screwed into the posts of the inside handle and the bolt with handle attached was fed through the door into the posts of the exterior handle. The bolts for the outside handle were fixed in place by screwing two small fastener Allen screws into the predrilled and tapped holes. The bolts, like everything that Martin Pierce’s company makes were custom made for this project.
After machining and bench testing each handle was polished by hand using a variety of buffing wheels and sanding compounds and then cleaned with a solution of sodium hydroxide and then passivated in a citric acid.
As has been described above a lot of thought and skill is needed to create truly unique door handles.