I popped the top on a quart can of shellac today, and POW; the lid hit the ceiling of the garage, sending shellac everywhere. What did I do wrong?
Jeff Jewitt: You did nothing wrong. There was a defect in the application of the special protective lining that’s applied to the can, and the steel was exposed. Since shellac is acidic, it reacts with the exposed metal, and a byproduct is a gas that forms inside the can. While I cannot speak for the manufacturer, this is not an isolated case. I think if you contact them they will be happy to replace the product.