Originally Posted by
Patrick Chadwick
Not in the way that, say, paint in the tin goes off- shellac finishes over a century old can be polished up with an alcohol-moistened rag to remove fine scratches. And as you have seen, it performed quite satisfactorily when you applied it to the stock.
But you were handling a can not of shellac, but shellac solution - i.e the flakes dissolved in (presumably) alcohol.
That appears to have been the mistake. The shaking turned the contents into an alcohol-vapor powered shellac aerosol.
If you had simply prised the lid off and stirred the contents, it would not have happened.