3-d printing

Fabricating the Past

Today in the Archaeology Lab at the Virginia Museum of Natural History, we are hard at work preparing for an upcoming exhibit, Exploring Virginia. Part of the exhibit discusses some of the early European explorers of this corner of the world, using maps to illustrate how their reports changed how European powers viewed the continent.  We have on display almost 90 mounts of animals mentioned in their journals and material culture from the Native American groups that they met on their travels. The remainder of the exhibit discusses how we know about the past today, whether it’s from historic journals and maps, or through archaeological excavation and interpretation.

 

Virginia Museum of Natural History - Exploring Virginia exhibit

Virginia Museum of Natural History – Exploring Virginia exhibit

We decided early on in this exhibit development to use a large number of artifact replicas – we wanted lots of objects that visitors can touch and handle which is unusual for most exhibits. We’ll still have plenty of actual artifacts on display but wherever possible we are incorporating replicas for interactives and touchables. There are two ways we have been producing replicas for the exhibit. The first is through 3-D scanning and printing. We have partnered with Dr. Bernard Means of the VCU Virtual Curation Laboratory (https://vcuarchaeology3d.wordpress.com/) to select and create over 100 3-D printed artifacts! Interns from the Virtual Curation Lab and interns and volunteers from the VMNH archaeology lab have been finishing and painting these replicas getting them ready for viewing and handling. One of the VCU/VMNH interns was Brenna Geraghty, who has her own blog entry today so I’ll let you read about her exploits in her entry (http://www.dayofarchaeology.com/brenna-geraghty-virginia-museum-of-natural-history/).

VMNH volunteer Rebecca Moore painting 3-D replicated passenger pigeon bones.

VMNH volunteer Rebecca Moore painting 3-D replicated passenger pigeon bones.

The second way we produce replicas is through molding and casting. This is a multi-step labor intensive process that produces resin replicas nearly identical in shape to the original artifacts. The first step in this process is surrounding the object with clay so a silicon mold can be created. Most of our molds are two-part molds where first one side, then the other of the artifact is molded, the two parts of the mold fit together, the silicon is poured into the mold, then the mold can be taken apart to reveal the replica.

Clay being warmed under a heat lamp and the construction of one part of a two-part mold.

Clay being warmed under a heat lamp and the construction of one part of a two-part mold.

The pink material you see in this photo is silicon and is covering the top half of the artifact. The bottom half of the artifact is encased in clay. When the silicon sets, it will be removed, the artifact will be turned over, and a silicon mold will be made of the bottom half of the artifact. The two silicon parts then fit together, resin is poured into the mold, and a replica is made.

IMG_3614

Silicon molds.

Here you can see three molds – one one-part mold and two two-part molds held together with rubber bands. The rubber bands hold the two pieces together so that resin doesn’t leak out of the mold seams.

Archaeological dog burial feature for a discussion about the early presence of dogs in North America.

Archaeological dog burial feature for a discussion about the early presence of dogs in North America.

This is one of the more complex replicas that we are producing. We are reproducing an archaeological dog burial feature for a discussion about the early presence of dogs in North America. For this exhibit piece, Ray Vodden, who runs our molding and casting program, made a cast of every skeletal element recovered from the burial. Those casts are now being laid out to mimic the archaeological feature – you can see a magnified field sketch of the feature standing up on the table. The casts are being held in place by clay. Once all of the replica elements are in place, we will build a clay dam around the entire piece and make a silicon mold and a resin cast of the entire feature. That will then have texture added to replicate soil and be painted to look like the original feature. One of the benefits of creating a replica of the entire feature this way is that we can reproduce it if there are other museums who would like to have a copy for exhibit. We make various sets of artifact and fossil teaching kits and this will eventually be added to our catalog.

Education and public outreach is an important part of our mission at VMNH. We hope that by incorporating more things that visitors can touch and handle, they take away a greater appreciation for Virginia’s past