Experiments 2-4 moved indoors as the weather changed. I was still working with the same batch of ocean water I had gathered for the controll in Stage 1.
Experiments 2-4 moved indoors as the weather changed. I was still working with the same batch of ocean water I had gathered for the controll in Stage 1.
Experiment 2
As a reenactor I sometimes have to make choices to substitute a modern method or tool. When I started this research I did not have a fire pit (and am still unable to use one at my home). Due to this I attempted to replicate the surrounding heat of a fire by direct boiling ocean water in a cup that was placed in a metal pot to protect my stove top. While not the most accurate method it was easily accessible, safe, and the closest I could get at the time.
My theory was that the heat would help drive the water back from the exterior surface of the cup retaining more salt inside. This was partially correct.
Much like the control attempt a large portion of the salt was lost through the terra cotta, forming crystals on the outside of the cup. This time I was able to collect some salt in the bottom of the cup which gave me hope.
Experiment 3
While I was working on attempt 2 I found an article that contained details into a briquetage find in El Salvador that included a small percentage of pottery shards that had a glaze. This made me wonder if pottery seconds ( misglazes, chipped rims, etc) might have been used in Britain as well. Looking over my kitchen I had a tiny cup that I could easily replace so I decided to include it in my experiment. Despite being much smaller than the unglazed cups it retained far more salt and due to its size it was much faster to experiment with. There was not enough salt to form a true cake so I attempted a second layer of salt water poured directly over the rough salt in the bottom. This again boiled down quickly and created a thicker cake of salt. Further research in The Red Hills of Essex (9) showed some glaze on the supporting pillars and firebars but none on the troughs and cups so this process was was set aside as highly unlikely.
Experiment 4
In this experiment I wanted to follow up on the layering I had done in the glazed cup as well as revisit the theory that the rough clay might reach a maximum saturation point. I began by filling the cup ⅓ full and boiled it down to a sludge then refilled it to the ⅓ point again and repeated the process. This was going very well and I could see a distinct cake starting to form after the 4th or 5th round. By round 7 it was solidifying nicely though this was very time consuming. Unfortunately I got distracted on round 8 and the salt was allowed to fully dry. I attempted to add more ocean water and the thermal shock caused the pot to crack spilling out the contents into the safety pan and rapidly boiling off. This left a fine salt chalk that also picked up mineral elements as it interacted with the metal pan. While technically a failure this was a great illustration and reminder that the speed at which salt is evaporated impacts the size of the salt crystals.