The hull and many of the artefacts are susceptible to the development of acids which can destroy the wood structure.
The acid originates from sulphur species incorporating into the wood whilst on the seabed which eventually can transform to acid when exposed to oxygen.
This is particularly a problem in artefacts which originally contained iron, as the corroded iron has migrated into the wood and drives the sulphur reaction to form acid.
Therefore, a way to inhibit acid production is to remove the iron by reacting the wood with a suitable complexing agent. This method has been used extensively at the Trust as a surface treatment and it is now being explored as a submersion treatment for entire artefacts.
Application of Strontium carbonate treatments to artefacts which are showing the presence of sulphate salts.
Many of the waterlogged archaeological wooden artefacts have the potential to form acids due to the presence of iron and sulphur. The sulphur originates from biological reactions which occurred on the seabed and the iron is present due to the corrosion of original fixtures. While they were exposed to limited oxygen on the seabed these posed little threat but can form acid when exposed to oxygen for extended periods of time. Removal of iron is one way of treating this problem and is explored in another section. Another route is to neutralize the products. At the Mary Rose, a treatment of Strontium carbonate is being pioneered to neutralise acids and elements which have the potential to form acids if left unattended. A stable product is formed which can remain in the wood.