Pour one qt. of water into a saucepan. Add 16 tbsps. of flour to the water.
Bring to a boil over medium high heat, stirring constantly until thick.
Remove from the heat and allow the starchy solution to cool.
Put on rubber gloves and measure 5 tbsp. lye into the solution. Stir to dissolve.
Apply the paste to the area where you wish to remove the finish, using a clean, soft cloth.
Allow the paste to remain on the piece until the varnish or shellac softens. This may take up to 25 minutes.
Scrape off the paste and the softened finish using a thin paint scraper. Take care not to dig into the wood.
Repeat this process until all shellac or varnish is removed.
Rinse the wood with a mixture of one cup vinegar and one gallon of water. Rinse several times with plain water.