Problem Solving Forum

| More

June 5 - June 9, 2017

What would be a reasonable service life for a two-coat, zinc-rich epoxy/epoxy mastic system, about 200-250 microns, in a marine environment? What evidence is there from the field?

Selected Answers

From Larry Muzia of Exceletech Coating & Applications, LLC on June 13, 2017:
I no longer have a copy of the Gordon Brevoort study on  coating life expectancy in various environments; however, experience allows me to interject the following. First off, I will assume this is carbon structural steel, so the first order of business is what type of surface preparation did the steel receive before the application of the organic zinc. It will have an effect on service life. Assuming an SP 10 prep followed by removal of non-visible contaminants followed by sufficient film thickness of a highly loaded zinc-epoxy, this system will be a reasonably good primer choice in a marine environment. The question I have about the epoxy mastic is,  does i,t have aluminum platelets within the composition. As typical epoxy mastic is noted for lower film stress which can equate to permeability rating. The mastics with platelets have the ability to impede the passage of the water molecule (electrolyte) and can enhance the performance. The other consideration is where specifically is the marine environment? Colder climates also have lower corrosion rates than for example the Space Coast here in Florida. My opinion is on average this system would perform 8-12 years with proper maintenance in your average atmospheric marine environment .

From Regina Montgomery of Thordon Bearings Inc. on June 13, 2017:
I would be interested in hearing experiences for coatings of this thickness. My experience is with 160-280 micron, two-part epoxy coatings designed to provide up to 15 years performance integrity for protecting marine propeller shafts. Service life is, however, based on typical conditions and can't take into account extreme conditions such as damage caused by ropes, groundings, or flotsam. Other difficulties include stray currents or marine growth where anti-fouling protection falters, which cause coatings to be compromised.

Please sign in to submit your answer this question    

Tagged categories: Coating Materials; Epoxy; Immersion service; Marine Coatings; Zinc-rich (inorganic); Zinc-rich (organic)

Current PSF Question | Submit a PSF Question | Full PSF Archive


KTA-Tator, Inc. - Corporate Office

Axxiom Manufacturing

Abrasives Inc.

Western Technology Inc.

Sauereisen, Inc.

HoldTight Solutions Inc.



Technology Publishing Co., 1501 Reedsdale Street, Suite 2008, Pittsburgh, PA 15233

TEL 1-412-431-8300  • FAX  1-412-431-5428  •  EMAIL

The Technology Publishing Network

PaintSquare the Journal of Protective Coatings & Linings Paint BidTracker

EXPLORE:      JPCL   |   PaintSquare News   |   Interact   |   Buying Guides   |   Webinars   |   Resources   |   Classifieds
REGISTER AND SUBSCRIBE:      Free PaintSquare Registration   |   Subscribe to JPCL   |   Subscribe to PaintSquare News
MORE:      About   |   Privacy Policy   |   Terms & Conditions   |   Support   |   Site Map   |   Search   |   Contact Us