12 Essential Processes: Step 7- The Right Water Makes A Difference

At Green Packaging Inc., our anti-corrosion supplies for sale do the heavy lifting in reducing occurrences of corrosion. They can’t do everything, though there are a number of factors that can cause oxidation before metal pieces ever make it to their packaging areas. Unpurified, too low or too high PH water can result in more common corrosion of pieces, especially ferrous metals.


There are two common types of water used in metalworking fluids, distilled and deionized.

DOVER AIR FORCE BASE, Del. -- Airman 1st Class Jonathan Trammell welds a part on the remodeled mortuary transfer vehicle.  Airmen from the metal technology shop here redesigned the inside of the truck to increase the capacity from two to six transfer cases.  Airman Trammell is assigned to the 436th Equipment Maintenance Squadron.  (U.S. Air Force photo by William M. Plate Jr.)

Distilled Water- The oldest method for purifying water, water is boiled into vapor and separating the water molecules from anything else in the water and then cooled back into its natural liquid form. This form of purified water can still carry contaminants that have a boiling point close to water.


Deionized Water-  Deeply demineralized, deionized water is considered “ultrapure” and is purified using a multistage process that integrates a reverse osmosis membrane. Ions in the water are almost completely removed resulting in a less reactive liquid.


For these reasons, deionized water is favored over distilled water in metalworking fluids but both are more effective than unpurified water. Both forms of purification rid water of mercury, lead, strontium, phosphates, nitrates, pesticides and other contaminants. 


So why does the water in your metalworking fluids make a difference? Reactivity and pH.


A pH, how acidic or basic a liquid is, is a factor determine whether water will protect or corrode a metal piece. A pH slightly above nine won’t react with ferrous metals (iron, steel), but can harm non-ferrous metals (copper, silver, aluminum). This means that if ferrous and non-ferrous metals are being worked through the same fluid station, the water should be dumped and changed depending on the metals going through it.


Bacteria and divalent ions tend to react with soaps wetting agents and emulsifiers, forming compounds that, due to their limited solubility, deplete rust inhibitors and increase the likelihood of corrosion. The reactivity of imperceptible agents in metalworking water make metal much more susceptible to oxidation, so using properly purified water is a must. 


Join us next month when we’ll be deep-diving pH levels in metalworking and cleaning fluids. Until then, give us a call or order online to buy rust preventive supplies.