Heaters for Electropolish Solutions
Electro-polishing is the opposite of plating. Metal is removed through an electro-chemical reaction that takes place on the surface of the metal and produces a smooth and shiny surface.
This solution is usually made up of Sulfuric and Phosphoric Acids. The two heater sheaths that are impervious to this combination are PTFE coating and Quartz. With either immersion heater type, over-the side or L-shaped bottom heater, salt buildup will occur on the sheath. Yes, even on PTFE! With PTFE the elements have to be hand cleaned. With quartz, you can use a rubber scrapper to remove the sludge. You must be careful because it is glass!
The phosphoric-sulfuric bath is viscous and dosn’t transfer heat well. Using de-rated Quartz heaters provides the chemical resistance and extra life for this application. Quartz heaters are preferred because this type of heaters are manufactured in (3) parts; a PTFE guard, a quartz tube and a coiled resistance-wire heating element which can be replaced economically.
The heaters can be ordered de-rated by adding a “D” to the part number. By doing this, a standard AQ-282C, that is normally 4 KW is transformed into a AQ-282 DC. This would make the heater 2 KW . So you would need 2 heaters to keep the kW rating the same.