How much to use and how long to etch will, of course, vary depending on what metal you use and what effect you’re after. Below are two examples.
Example 1: For a production run of 50 titanium parts, approximately one square inch each, I use one cup of Multi-Etch in a two-cup Pyrex® container, heated to about 150° F. You can use a thermometer or look for the built in Multi-Etch bubbles which tell you when it’s ready to use (visual check.) These tiny bubbles appear when the Multi-Etch is brought up to the correct temperature. I dangle a pair of earrings from a niobium wire into the Multi-Etch for 3 to 10 seconds and then rinse in distilled water. If I did three production runs a week, I would change the Pyrex® cup about every three months. If you wait too long, the cup can shatter and make a mess.
One unit of Multi-Etch can etch approximately 1,500 square inches of titanium when dipped for three seconds at 120-150ºF.
Example 2: I manufacture a line of titanium wedding rings with platinum inlays. As all platinum fabricators are aware, the accepted method to remove cross-contamination prior to welding or soldering is a 15 minute soak in nitric acid or bisodium sulfate. With Multi-Etch®, a 15-second dip is sufficient to eliminate all impurities that could interfere with a perfect weld or solder joint. I dangle the platinum from a niobium wire into the Multi-Etch for 15 seconds and then rinse in distilled water. It’s now ready for a perfect weld.