HARD DEWAXED WHITE (BLEACHED) SHELLAC
Are you considering completing your guitar with a shellac finish? Here is an easier solution, a shellac finish but with the durability of polyurethane.
This unique Hardened Shellac creates a film with high resistance to heat, water and alcohol, yet it is used in exactly the same way as any normal shellac. It can be applied with a rubber as French polish, brushed, sprayed and dipped.
HOW IS THIS POSSIBLE?
After shellac has been dissolved in ethanol* it is possible to introduce additives that cause the shellac to cross-link after it has dried. This cross-linking takes about 20 days to completely cure, less in hot weather.
Hard Shellac is applied in the same manner as any normal shellac. The drying time is the same as regular shellac. ie: almost instantly.
Water dye may be used under the shellac to change the colour of the timber to be polished. There is no need to use a sanding sealer or anything else under the Hard Shellac, however you may apply a weak solution of the shellac as a first coat eg. 1 part Hard Shellac to 8 parts ethanol*. This can be fine sanded after it has dried. This will seal the timber and dye (if used) and will give a beautifully smooth base upon which to build your finish.
Hard shellac has a shelf life of 18 mths from the time it is made and all bottles are clearly labelled with the Best by date. Once it is out of date it is no longer much good and should be disposed of.
For more details on using shellac get a copy of "A Polishers Handbook" by Neil Ellis.
* ETHANOL (also commonly known in Australia as - 100% Industrial Methylated Spirits or 100% IMS. and sometimes called pure alcohol or denatured alcohol. If you can't get 100% IMS then it is strongly suggested that you use 95% rather than cheap methylated spirits without a percentage specified, as this by law can contain up to 40%+ water and will ruin the shellac and your finish)