Quandary on ice sticking to zinc plated parts 1

[Doc454]

I have a customer that places our product in a freezer drawer. It must function after a "Florida Test", wherein the freezer drawer is opened for several minutes in a high humidity environment until condensation forms....then closed until it turns to ice....ad nauseum. What is the best final coating to apply to our steel parts, that are Zinc electroplated, with chromate coating, Leachant/sealant coating....to prevent the ice from sticking to the surface and thus hindering operation? Wax final coat? A voice of experience in this wilderness of unknowns would be very welcome...Thanks, Art

 

[TVP]

You are on the right track with regards to a wax final coat. Many of the electroplating companies that process threaded fasteners use a final treatment after chromating to produce a low-friction coating. Sealing is one option, which are typically either hard coatings (silicates) or soft layers (waxes). Ask what type of seal you have been getting-- you want a wax-based coating/lubricant, such as MacDermid's TNT 11. The following link has some information:

http://macdermid.com/industrial/topcoats.html

 

[Doc454]

Thanks.
I'll work on improving the final coating immediately.

 

[MiketheEngineer]

IMHO - Ice can stick to ANYTHING.

What happens when the wax coating goes away??

 

[CoryPad]

I worked on a similar issue with water adhesion to coatings (electroplating and multilayer zinc/organic) and ice formation during low temperature exposure. In addition to wax, you can investigate topcoats with PTFE (also known as Teflon). PTFE has low surface energy and so the water will form droplets rather than sheets. Then the question is whether the droplets or sheets evaporate, separate, or other during part usage. Good luck.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Doc454]

TVP:
Thanks for the tip on MacDermid...It was quite a lot of fun.
I started trying to contact someone in Hong Kong, then Corporate in Denver, then the webmaster....all my e-mails bounced..! Without alternative suppliers in the marketplace and a sense of humor...this could have been frustrating. Fortunately, Pavco seems easier to reach with a sales/tech inquiry. I
This, plus Cory's tip has me on the right road...saving a LOT of time.
Art

 

[Higgler]

Google Hydrophobic coatings. Makes water shed off by forming little fingers/bed of nails in a two step application process, not certain about cold icy water.

kch