I have found an easy way to thoroughly clean black coal and diesel oil smoke off insulators. I thought you readers might like to try it. It really works. I have just cleaned 30 insulators and they look as if they were just made!

The initial tip came from Marion and Evelyn Milholland's Bicentennial Edition, page 187, where they suggested oxalic acid. Please don't hesitate at the word acid, for oxalic acid doesn't match the image of the chemistry lab with bubbling acid eating a hole in the top of the metal cabinet! I have used it several times and it seemingly is a mild but effective glass cleaner.

Oxalic acid is a crystallized acid. Ask your larger chain drug stores to order it from their drug wholesaler. $12 bought 5 pounds. I use a ceramic bowl purchased at a discount store in the garden department. It measures 10" wide and 10" high. Pour in six quarts of water, add eight tablespoons of oxalic acids and stir to dissolve.

I use long metal tongs like barbeque tongs to place the insulators in the solution. I let them soak at least six hours. Upon removing the insulators, scrub them briskly with a metal kitchen scrub pad like Chore Girl. Use Ajax and they will be completely clean. Oxalic acid doesn't remove the film, but it greatly softens it so that scrubbing will. Don't use this method on carnivals, and don't scrub over very faint embossing.

Today in a hardware store I found the perfect brush for cleaning the inside of insulator pin grooves. Ask the employee to show you wire brushes designed to be used with a soldering iron, to rub copper tubing. This was the explanation I was given as its intended use. The brush is 6" long, has a 3/4" circular wire brush at the end which fits perfectly into the pin groove cavity.

Lastly, store the acid outside in a utility room even though the fumes are negligible. I have had no problem with skin contact although I make every effort to avoid contact.

I hope the readers will be as pleased as I was using this method. I think you will find it will yield insulators which can be displayed in front of window showing their full beauty without impurities.