||With the help of Roberto Regazzi a Bologna Maker, I was able to obtain lumps of Pozzolanic rock which contained similar elements, and I spent awhile experimenting with applying this. In the end Prof. Raphael worked out a mixture of salts which he thought would contain all the necessary elements and would be both benign to the wood as well as the person handling the stuff. We took the proportions from one of Claire Barlows results...the one which contained the highest Calcium content.
The major problem with the resulting mix was how to get it to adhere permanently to the wood. Early attempts just brushed off once the mix had dried. It occurred to me that as the mix had a high Silica content as well as Potassium, Calcium, Aluminium, Sulphur, Iron and traces of Titanium and Magnesium, why not apply the mixture in two parts.
So, the recipe, (parts per 100)...based approximately on Barlow Spectra 18 of sample 21 Goffriller cello.
Magnesium 3.6, Aluminium 10.0 Silicon, 11.6 Phosphorus 2.4, Sulphur 6.9, Chlorine 6.07, Potassium 5.2 , Calcium 42.3, Manganese 0.3, Iron 10.6, Sodium l.3.
In my attempt to produce a slurry containing these elements in roughtly these proportions, I mixed 45 gms of Calcium Lactate with l0 gms. Alum, 3 gms. Manganese Sulphate, 3 gms. Titanium Dioxide, 5 gms Yellow Iron Oxide 10gms Mica Powder with ordinary tap water (containing Chlorine) to make a thin suspension. Separately I prepared a 50% solution of Potasium Silicate.
Using a cloth well wetted with Pot Silicate Solution, I ragged a coat on to the bare wood. While the Pot Sil Sol was still wet(this requires fast working) I ragged on a liberal layer of the slurry of salts. The chemical reaction takes place within the fibre of the wood and once dried, forms a hard concretious layer (basically) Calcium Silicate which cannot be rubbed away and could even be burnished with an agate to an eggshell texture. A test I made in a jar with the mixture together gives a Ph reading just over 7.
The appearance of the layer on the wood is at once very alarming as the wood grain appears to be almost totally obscured by a plaster like covering. Rosin oil renders the layer perfectly invisible up to about l2 microns in thickness as the refractive indices match very closely, never again to be seen without the scanning electron microscope, but does not