Categorized | Medical Device, Solujet

Solujet Inhibited for Cleaning Aluminum

Aluminum Plate Cleaning

Q. Specifications indicate that “Solujet is inhibited for Aluminum. Corrosion testing is advisable.” What does this mean?

A. Solujet™ Low-Foaming Phosphate-Free Liquid contains sodium metasilicate which acts as a corrosion inhibitor to stop alkaline attack on aluminum. Solujet detergent would not cause alkaline attack when used for cleaning aluminum as long as the bath is not overused and the metasilicate depleted.

There are galvanic (forming a battery) attacks on aluminum that involve interactions with other metals that may be dissolved in the cleaning solution from prior use, or that may be present as metal in the tank or part being cleaned.  This form of attack will happen with just about any detergent solution including Solujet cleaner. Ideally you should not clean other metals in baths used to clean aluminum and should not have other metals that have significantly different galvanic potential than aluminum present in the cleaning solution.

If there is any concern that there may be other metals involved, then some testing may be advisable. If the aluminum parts being cleaned are very high value parts, then some testing would also be advisable. Certainly Solujet detergent is designed to clean aluminum safely. Aluminum is a reactive metal, especially if it has been recently machined, cut or tooled so that there is exposed, freshly cut aluminum that has not had a chance to form a protective passive layer of alumninum oxide.  This happens naturally with exposure to air. If the protective passive layer is not formed then you can get a varying array of potentially strange galvanic reactions that are not technically corrosion. But, this will very often result in discoloration due to deposits of whatever other metal or metal oxide is present on to the surface of the aluminum.

You can also request a free sample of Solujet cleaner, and any of our other detergents, by completing the questionnaire at Get Sample.

For more information about any one of our Alconox Inc. Cleaners, consult the specific technical bulletin for each product HERE. Or click here to access each of our detergent’s  Safety Data Sheets