July 2023

Conservation work continues on the ship remnant found at the Hotel Indigo Site (44AX229). After soaking timbers with difficult to remove metal fasteners in more ammonium citrate between late 2022 and early 2023, the team at the Conservation Research Lab (CRL) examined the timbers both visually and using x-rays to determine how well this chelation was removing the embedded metal. This additional soaking time removed much of the surface staining and iron in and around the fastener holes on many of the timbers. CRL staff then mechanically cleaned the fastener holes one last time before preparing to place them into the polyethylene glycol (PEG) solution. In total, 46 structural timbers (frames or keel) are ready for treatment with PEG.

However, iron pins and associated concretions remained in and on some of the timbers including the bow stem. As seen in this picture, there is still some orange staining indicative of iron towards the top left corner of the timber. This timber is being soaked in a slightly higher concentration ammonium citrate solution for another few months to remove this remaining corrosion product. This chemical process will not remove all the corrosion product, but it should remove enough that the bow stem can safely move to the next step in the conservation process. After it is soaked in PEG and freeze-dried, any remaining iron and corrosion product within the structural timbers (keel, frames, bow stem) can be removed in a few different ways including applying targeted poultices within the fastener holes or by placing the entire timber in a chamber filled with ammonia gas.