Filling in Lyndhurst’s Working History: Stove Grill Replacement with Plastic Casting

By Special Contributor posted 10-12-2017 11:08


By Emma Gencarelli 

Every summer, Lyndhurst—National Trust Historic Site in Tarrytown, New York—hosts a handful of Preservation interns from different academic programs, locations, and backgrounds. This year I was fortunate to be one of them. The interns’ projects vary from year to year. The work of this year’s group included replicating a component of a historic stove that has been in the house since the late 19th century. Previous interns have used this same casting process to replicate decorative brackets during the Bowling Alley Restoration Project, and staff in earlier years also used this method to re-create decorative architectural finials on the mansion’s veranda. The use of plastic casting on the Lyndhurst property has, so far, been restricted to replacing missing architectural features, but this year’s project shows how this process can be important for filling in gaps in collections.


Lyndhurst Mansion in Tarrytown, New York. Credit: E Gencarelli


Previous examples of casting done at Lyndhurst: the mold and re-created bracket for the Bowling Alley on the left and an unpainted plastic cast of the veranda finial on the right. Credit: E. Gencarelli

The Kitchen Stove

Presenting the story of Lyndhurst includes exploring the working lives of the staff, so having a complete stove to show the evolution of kitchen and cooking spaces during the house’s key period of use was integral to that story. The basement of the Lyndhurst Mansion holds a c.1880 dual fuel gas and anthracite coal range by Duparquet, Huot & Moneuse Co., but the small grates that rest over a gas element for grilling were missing.

Showing where the grill grate is missing. Credit: E. Gencarelli

Re-creating the Grill Grate

Lyndhurst managed to locate a similar stove with its grill grate still intact at The President Woodrow Wilson House, National Trust Historic Site in Washington D.C., and borrowed a portion to use for the casting project. Upon receiving the grill grate, which was fabricated of cast iron, it became clear that reproducing it (while not damaging the original) was going to be a tricky because of its shape, unlike with previously casted objects that had flat edges for easy extraction. Having overseen previous casting projects on site, Restoration Project Manager Tom Richmond guided the interns in each step of the process.

The Original Grill Grate from the Wood Wilson House, Photo Credit: E. Gencarelli

Building the Mold

The first step was to create a form in which the grill grate would rest so that the first part of the casting, the silicone mold, could be made. This was done simply with wood, screws, and mold release compound so it could be easily taken apart later. Using a product called Rebound by Smooth-On, Inc. interns poured the silicone over the grill grate inside the wood form to set up. The curing time for the silicone is short, but for good measure it was left to rest overnight. From this rubberized mold the actual castings would be made.

Pouring the silicone over the borrowed grill grate. Credit: H. Glor

Casting the Grill Grate

Once the silicone mold was cured completely, the wood form was removed and the original iron grill grate had to be removed from the inside of the mold using a combination of razor blades, pry tools, and brute force. Cleanly extracting the original grill grate with no damage to the silicone meant that the first step of the process had been a success and that the future plastic castings would also be viable. The silicone mold was then placed back inside the wood form, re-enforced with clamps, and then sprayed again with mold release compound. Using the plastic compound Smooth-Cast (also from Smooth-On, Inc.) which sets up and cures in a short time, the mold was filled and the plastic set up after a few short minutes.

The silicone mold and grill grate separated and ready for casting. Credit: H. Glor

Prepping the Plastic Grill Grates

As with the original grill grate, the plastic pieces had to be extracted from within the silicone mold. Measurements had determined that it would require four-and-a-half grills to fill the empty space. Allowing for possible errors or inferior castings, several grates were cast, trimmed of extra edges created from the casting process, primed, and then painted in a matte black to match the original patina of the cast iron grill grate. Once the paint was dry (and one grill cast trimmed in half) they were ready to be placed in the stove!

The unpainted plastic casts in the stove. Credit: E. Gencarelli

The Stove is Whole Again

The stove in the kitchen at Lyndhurst is now complete, enabling visitors to better understand the downstairs story and the lives and roles of those who utilized those working spaces for the family upstairs. Visitors who take a tour of the kitchen often expect to see the same features that they find in their homes today: refrigerator, counters, sink, pantry, and stove. Because of this replication project all the functions are recognizable in the kitchen. Taking part in a project concerned with an object, not architecture, has shown me how preservation of objects can also be important for presenting the complete story of a building and the spaces inside.

The stove complete with finished grill grates, which blend in seamlessly with the original pieces. Credit: E. Gencarelli

Emma Gencarelli is a restoration project assistant at Lyndhurst. She has a master's degree in historic preservation from the University of Delaware.


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