Fresh news have come from our bamboo shingles and the various coatings we have tried to waterproof them. Remember we had tried:
- resin and turpentine
- shellac and spirit
- black japan
Of the three, all exposed to a month of scorching sun and pouring rain in Bharatpur, Nepal, the black japan seems to be the most efficient, while others, especially the resin has peeled away. Since we have not set a proper experiment it is hard to tell whether it is UV light or rain or a combination of both which is causing the rapid degradation of the coating.
We will run more experiments soon to find out what other various coatings can be used. We intend to try linseed oil and wax and we will try to expose smaller samples to various conditions so we find out exactly what are the weaknesses of each kind.