Ironwood Elixir

One of the innovations that heralded the beginning of the Age of Progress is the alchemical mixture known as Ironwood Elixir. A number of alchemists from from all over the civilized world have tried to take credit for this wondrous advancement but none could provide the official documentation or research materials to prove it.
When this liquid is applied freshly cut and sanded wood, the material hardens to be as strong as steel. Applications of this ship hulls, building supports, weapons, and shields. Items can be carved and shaped as usual; then the elixir is applied afterward, making the item incredibly strong. Applying this to Balsa wood is the basis for Loftwood, the primary material used in the construction of Airships.
The formula has been a closely guarded secret known only to select alchemists throughout the world. The secret is guarded jealously so that the price of Ironwood creations can be regulated.