The alchemy of steam
The water bubbled in the black cauldron and disappeared down a copper conduit into a steel box wreathed in flames. Steam hissed out of a second copper pipe and into the wooden box of ash poles, heating them to a temperature where water evaporated from them. The tubes within the wood remained unchanged but the lignin, (a sort of tree glue) that holds the cells together, melted and allowed the fibres of the wood to be bent into an arc over a wooden structure. Held in this position, the lignin will reform and harden so that the wood takes on its new curved shape. The poles will have lost so much of their water content, they will be two thirds lighter than when we first cut them down. But first we have to wait five weeks…..
On a day of radiant summer heat and blue skies, the Wood Sisters met for the great Steaming Day of the Red Tent Poles. This was the a fulcrum moment, when all the work of the past 3 months, cutting down poles, shaping them, building a steam box and former and drawing on paper the shape we wanted the tent to be, the moment of truth had arrived! Either the poles would snap or refuse to bend, or…. the steam would work its magic and we would have a former taut with poles for our dome shaped red tent.
The pictures tell the story better than words:
While we wait for the poles to cook for an hour, Toby shows us how to mark up the lintel and sill of the doorway to the tent.
So with 18 poles bent (and no breakages!), we put the second batch of poles into steam for an hour and turned out attention to keeping the fire roaring and working on the wheel rim.
Now the second lot of poles were steamed and ready to bend.
As pole after pole bent successfully.
We used corrugated iron and red plastic to protect the poles as they dry and harden and we caught a glimpse of what the interior of the tent may feel like…
It was a deeply satisfying and exciting day: successful, fun and inspiring. We headed home a little weary, a little sun burnt but glowing inside and out.