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Ultraseal vs. JS-500

Does anyone know the difference between the JS-500 plating and the ultraseal finish or sealer that is applied to zinc plated parts? We are wanting very good salt spray resistance and can't find any info on the Ultraseal or Sealer vs. JS-500

Marty Hall
Purchaser - Joplin, Missouri, USA
2007

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JS 500 is a Macdermid trademark for a plating process. Depending on the articles you read, it can be the sequence including the zinc or zinc iron plating process plus poatreatment, or just the posttreatment apparently. It's their trademark so it means whatever they want it to mean -- but I'd say it's the topcoat and usually applied by dip spin rather than immersion. Anyone using it is welcome to correct me.

"Ultraseal" is more complicated, referring both to a vacuum impregnation used before the plating is started, and as a topcoat. I don't know what company offers Ultraseal, but a number of articles muddy the water by referring to "JS 500 Ultraseal" :-)

We can't print replies presuming to compare one proprietary product to another, but any clarification as to what these coatings are, where they are used, and how they are applied is welcome.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

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Ted, one correction. Ultraseal is a mildly alkaline silicate type sealant from MacDermid. It is similar to products from many vendors and also has many similarities to the sealant in the JS500 process (some people will say they are the same). MacDermid, to the best of my belief, licenses the JS500 process to shops that meet their requirements for quality and for the use of only their approved chemistry.

Gene Packman
process supplier - Great Neck, New York
2007

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Having worked with the finish in question let me say that both my peers are correct about both chemistries coming from MacDermid. They are both immersion coats applied usually over a zinc layer with a chromate film. This chromate film is trivalent today but was hexavalent up until the turn of the century. Both are alkaline in nature with a pH of 10.5-11.5 in a working bath.

There are three main differences in the two finishes. Ultraseal is more concentrated than JS500, but is made up at a lower concentration, so the working bath is about the same from that aspect. The second difference is that JS500 has an ultraviolet tracer. The last difference, as was pointed out above, is that JS500 is a licensed material.

Craig A. Barboza
- Freeport, Illinois, USA
April 11, 2008