Cleaning a slide rule is easy.
Slide rules are long sticks with numbers printed on them and a sliding bar. They are used to make figuring mathematics easier. Since the advent of home computers and scientific calculators, the use of slide rules has become less common. Although they are still used by some, they are also commonly collected. Cleaning your slide rule will help ensure that it lasts for years to come.
Instructions
Method One: Plastic Slide Rules
1. Fill a sink with warm water and a squirt of gentle liquid dish detergent.
2. Remove the cursor from your slide rule, which is the sliding part of the ruler. Most cursors will just slide off.
3. Soak your cursor and your plastic slide rule in the dish detergent and water for 15 to 20 minutes.
4. Use a soft kitchen scrub pad to rub your entire slide rule. Use gentle back and forth motions with medium pressure. Be sure to scrub the entire ruler, otherwise you may have patches of uncleaned area.
5. Rinse it off under running water.
6. Allow it to dry completely before reassembling. Gentle dry it with a paper towel or cotton rag and then leave it on the counter to finish drying.
Method Two: Wooden Slide Rules
7. Apply a squirt of gentle liquid dish detergent into a cup of room temperature tap water. Use a spoon to stir it together.
8. Dip a paper towel in to the dish detergent mixture. Squeeze the paper towel to wring out the excess water. You want the paper towel damp but not drenched. If you prefer, you can use a clean soft cotton cloth.
9. Rub the damp paper towel over the entire slide rule for one minute. If you find the paper towel has become dry, you can dip it back in the dish detergent and wring it back out as necessary. Use gentle rubbing motions. Also remove the cursor and clean it in the same method.
10. Moisten a clean paper towel in water, no detergent this time, and wring it out so that it is damp and not wet. Use this moist towel to rub the entire slide rule and the cursor to remove the detergent.
11. Dry the entire slide rule with a clean dry paper towel. Place the cursor back on your slide rule to finish.
