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Subject:
Re: Man o' War wood finishing

TMStock
Shellac has very poor solubility in oil, so likely some of these recipes are an attempt to increase solubility of that resin in oil and to get a tougher, more durable film by reducing the dried resin's solubility in alcohol and increase flexibility.

Bowed instrument makers use these sort of home-brew finishes all the time, as both spirit and oil varnishes are used on violins, cellos, etc. Once dry, it's very tough to tell whether the finish is a drying finish (solvent evaporated drying) or curing finish (cross-linking, polymerized cure), as both types of varnish may see both drying mechanisms at work, depending on the formulations.

Short oil versus long oil varnish formulations have been discussed...adding more oil will increase flexibility and likely reduce surface hardness of the film. Adding solvent will make brushing easier (to a point) or allow padded or spray application, and build film thickness more slowly, but the final film is similar to the unthinned finish, assuming the same dry film thickness is achieved.

Finally, Rule 1 of Murphy's Laws of Woodworking is in play here: if it looks stupid, but works, it's not stupid.

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