Enhanding Corrosion Protection

Q. I work out of Asheville, NC. We are currently working on an e-coat application involving aluminum castings (Engine blocks). We have heard of a pretreatment process called “Lifenite” that can be used prior to e-coating to fill in any porosity in the casting. I’m trying to find additional information about this product. B.B.

A.“Lifenite” is one of several trade names for a chromate conversion for aluminum to enhance corrosion protection and coating adhesion. Other trade names for the same pretreatment are “Alodine” and “Irridite”. This pretreatment does not fill the porosity. If porosity is a problem, impregnation with a resin prior to pretreatment and e-coating, My experience is that the chromate conversion pretreatment may not de necessary prior to e-coat depending what type of pretreatment you have for steel substrate. Check with your pretreatment and paint suppliers for a proposal to take to your customer. Many pretreatment suppliers have multi-metal conversion coatings that will provide the end use corrosion and adhesion requirements when e-coating

If you are determined that the use the chromate conversion pretreatment is required for these parts, your best source is a local electroplating operation. They usually have the necessary waste treatment processes to handle the chromate waste.