Designing for Function - Part 3 Making A Custom Door Handle

In previous posts we have used a stationary pull to illustrate how a custom piece of door hardware is designed for lost wax casting, but what impact does a functional handle with moving parts have? The answer depends on the function and varies depending on whether the design is for a door- knob or lever and whether it is to be used as an entry door set or as a handle set for an interior passageway or privacy (think bathroom) door.

In this post we will use the set lizard passageway set to answer the question.

The passageway set is made up of several components, some are cast but others are either machined in metal or custom made to order by fastener manufacturers like Seastrom.

While the back-plate is a relatively straightforward piece to cast, the levers (left and right) need to be cast with a square hole for the ferrule and spindle which are the components that connect the levers together and that will connect with the latch that depresses and returns the lever. The 2 patterns, one for each lever, need to be machined for a square hole and how you accomplish this will depend on the medium used for the pattern. A ferrule is then added either to the pattern or to the subsequent wax replica. For bronze castings we machine our own proprietary custom ferrules in stainless steel an alloy that bonds with the molten bronze but as it melts at a much higher temperature than bronze does not distort or melt in the process. For steel castings, as a metal ferule would melt, we incorporate the ferrule into the pattern. The ferrule acts like a sleeve to hold the square 8mm spindle and it is machined with a tolerance that allows the spindle to fit tightly. A “C” spring clip is added under pressure to the outer rim of the ferrule, and this holds the lever to the back-plate.

The lever set must also be designed to function with a tubular latch. The spindle passes through a square hole in the latch, a component made by another manufacturer and that has an internal spring that enables the lever to be depressed to retract the latch tongue and which returns the lever to throw the tongue.

Depending on the weight of the lever, an auxiliary spring can be added to the ferrule to assist the latch and help prevent any sagging. The auxiliary spring is made in spring steel and as part of the design process the back-plate pattern is made with a stop which limits the motion of the spring to a 33 to 45 range.

The mechanical demands and therefore cost to create a new one-of-a-kind piece for a client are inherently expensive.

Inspiration for Door Hardware from the Grand Canyon and Zion

The only question raised by our journey to the Grand Canyon and beyond, was why had it taken us 40 years to make the trip? We had heard wondrous reports from friends over the years but had chosen more exotic vacations in Europe and Canada and had relegated this local scene to the back burner. So, when our trip to Rome was cancelled, we found the silver lining to the Corona Virus and planned an RV trip to Arizona and Utah.

As my blog is written as an extension of our website I wondered what or how this trip had anything to do with our hardware designs, which in turn prompted the question of how nature influences our thought processes, specifically, Martin Pierce’s hardware designs. I have often stated that nature is the primary source of Martin’s design ideas, but the process is far from causal and is more subtle and indirect. While Martin does on occasion search out a plant or rock or animal as a study piece for a handle or back-plate, he spends more time simply and randomly photographing what he sees and finds interesting and in so doing creates a mental library of images.  

So, having explained the reasoning behind this post let me share some of the spectacular awesome sights we saw on this 9-day road trip in the company of Iris our canine family member.

Grand Canyon South Rim Storm Drifting In – The straight horizon created by the movement of the tectonic plates that raised the flat plateaus upward

Female Elk drinking rain water – the blurred pixels are reminiscent of the Impressionist Period

Look carefully to see the well disguised Grand Basin Gopher Snake. While this snake, as with most snakes is harmless, the jury is out on whether ophidiophobia would make a snake handle unmarketable. Our lizard collection of door handles is popular so maybe we should launch a snake collection we would love to hear your thoughts.

We took countless pictures but none captured the depth and magnificence of the Grand Canyon.

Easter Bunny Door Knobs

This bunny may have chocolate tones but being cast in solid bronze it is definitely not edible. Thinking of Easter bunnies, I followed Alice down the rabbit hole also known as the internet to research the origin of this Easter custom. Dependable Wikipedia sets out how the rabbit or rather the hare has possibly several ties to pagan times and has been associated with Eostre the goddess of dawn whose torches may have been carried by hares. Hares it seems have been celebrated by many from prehistoric times onwards as creatures of spring that herald lighter longer days and fertility to crops and mankind.

Our bunny door knob has more earthly origins and is based on a soft interpretation of this very soft animal. As a nod to the preferred diet he/she sits on a wreath of swirling vegetation all of which is cast in solid bronze and typically finished in a light antique brushed and oil rubbed patina. The bunny shape was designed so that all the legs and ears are tight to the body thereby making a round and compact door knob that fits easily in the palm of one’s hand. The bunny design is one of 4 nature inspired door knobs that collectively make-up our Netsuke collection, a collection whose namesake is the compact toggles used to fasten clothing. The Netsuke collection is interchangeable so a rabbit and frog or lizard or bee can happily co-exist on the same door, one on each side of the door. The netsukes can also be mounted on different back-plates to create a truly eclectic interior.

Colorful Door Hardware - How to Use Hot Patinas

Nature is a strong and continuous source of inspiration for our door handles and cabinet pulls so I wanted to complete this series of posts with a few pictures that illustrate this as well as providing information on how our yellow and maroon color patinas are made.

The dragonfly cabinet pull is an example of a hot chemical patina created with Sculpt Nouveau’s red and yellow dye oxide that are mixed together to create a maroon color.

To create the yellow amber tones of the butterfly we use a yellow and white dye oxide which we apply to the heated butterfly and once the desired color has been reached and after the pull has cooled down we apply small black wing markings with a  fine paint brush and a cold patina M20 product  by Birchwood Technologies.

Animal Cabinet Knobs and Pulls

The process for all of our hot patina finishes is the same;

Buff the bronze pull by hand or by using a buffing wheel buffing wheel and buffing disks, progressing as needed, from medium grit to fine grit disks. The disks we use are made by Standard Abrasives and made from a tough resin reinforced nylon fiber with aluminum oxide which acts as an abrasive element. Since the nylon web is un-woven it is more flexible and so will follow the contours of the bronze.

To remove fiber particles, dust or other surface impurities we clean the piece with an air pressure hose.

Blend the liquid oxides in a non-reactive container to achieve the desired color.

Heat the pull to about 200° and apply the dye oxide blend to the areas you want to color with a very fine paint brush.

After the casting has cooled re-buff any areas that need to be re-worked or where you want to expose the golden color of the raw bronze.

Seal with a clear wax or use tinted waxes to create to add a different hue.

Sources:

www.sculptnouveau.com

www.birchwoodtechnologies.com

www.birchwoodtechnologies.com