Plastics in Our Collections: Chapter 1

Posted on
Collecting latex from a tree
© User:Iamshibukc / Wikimedia Commons / CC-BY-SA-3.0

The Plastics Age

History is filled with ages that are tied to the innovation of materials:  The Stone Age, The Bronze Age, and The Iron Age. We are currently in The Plastics Age. Plastics have changed so much in our daily lives. Plastics are around us all the time.  They are in every electrical thing in our houses, in the clothes that we wear, in our furniture and the packaging of our food.

This means that as caretakers of historic objects, museums have to consider how long plastic materials will last in our collections. We focus on what we have to do and learn in order to care for plastic objects. We also study plastics in order to store them in ways that better ensure their survival. This is a complicated thing.  Plastics are not simple materials, and what works for one may damage another.  Some plastics have been around longer than others, so we know more about them. We can see how they’ve aged. For other plastics, we can guess at how they will survive (or not) based on their behaviors and chemistries, while still others are a gigantic question mark.   Read more

A tisket a tasket – I just finished a gasket!

Posted on
10 of 15 gaskets from the Starboard Worthington Pump before conservation treatment

This week I thought it might be fun to look at one of our more unusual types of artifacts that I’ve been treating. We have tons (literally) of iron and copper artifacts in the lab, but for every two pipe flanges bolted together, there is also one gasket keeping things tight. The humble gasket can be found throughout the Monitor’s engine room, sandwiched between the copper piping and iron machinery parts. Its job was to keep the fittings air tight and prevent leaks. Most gaskets are made from layers of rubber and textile pressed together, but we do have gaskets made entirely of rubber and a few that are actually leather.

In addition to the gaskets, rubberized fabric, buttons, and combs have also been recovered. Despite the evidence of wide use aboard the Monitor, modern rubber was a relatively new material in 1862. Natural rubber was used before the 1800’s, but due to its unstable nature, it wasn’t suitable for many applications. Thanks to a number of people experimenting with additives and curing processes, more stable forms of rubber became commercially available. For instance, Charles Goodyear (who’s patent is stamped on the Monitor buttons) is credited with patenting vulcanized rubber which is much harder and durable than natural rubber.   Read more