A Tovatech customer asked us about the cause and removal of a discoloration inside his Elmasonic ultrasonic cleaning tank. The location and size of the tank discoloration suggested to us that it was caused by the heater. We present here a tip on how to prevent discoloration (sometimes called “furring”) and if it occurs how to remove it.
Furring can show up in a variety of colors in an ultrasonic tank. It can occur if the unit’s heater is activated when the ultrasound is not activated. This causes the solution adjacent to the heater to reach very high temperatures resulting in discoloration. (It’s somewhat like placing an empty stainless steel pot on the stove and turning on the burner. You’ll soon get a discoloration.)
So, even though the tank may be filled, if the solution is not circulating there will be a significant temperature differences that can result in discoloration.
Avoid the risk of furring discoloration by activating the ultrasound at the same time you turn on the heater. This provides the bath circulation that dissipates heat immediately adjacent to the heater location.
Removing Heat-Caused Tank Discoloration
If tank discoloration due to heat occurs we recommend operating the cleaner using either elma tec clean S1 which contains citric acid, or a phosphoric acid based cleaner such as CC55, both available from Tovatech.
You can also work on the discoloration when the tank is empty by gently rubbing the stain with a wet cloth soaked with the solution. Important things to remember are being sure that the cleaned surface is thoroughly rinsed with fresh water to remove cloth fibers and never use an abrasive cleaner on an ultrasonic cleaner tank.
Furring and other issues that may arise when operating an ultrasonic cleaner are covered in our post on equipment maintenance tips. Please contact the ultrasonic cleaning professionals at Tovatech for additional suggestions on getting the maximum service life from your investment.