The First Word in Protective & Marine Coatings

A Product of Technology Publishing / PaintSquare
JPCL | PaintSquare News | Durability + Design | Paint BidTracker

March 7 - March 13, 2011

What is the effect on the permeability of a coating when you add additional coats, either at the time of the original painting or as a maintenance activity?

Selected Answers

From Joseph Schinner of Akzo Nobel Coatings Inc. on March 8, 2011:
Let's cut to the catch: Those who specialize in tank linings, corrosion protection, waterproofing, etc., with coatings where permeability is of the essence usually prefer multiple coating layers, even within the same coating type (situation dependent, of course). It was proven long ago in the field and in the lab that there is a synergistic enhancement with using 2 or more layers of the same coating. This is frequently superior to that coating at the same or even higher total film thickness as a single coat. Mutiple layers provide a predictability that minimize failure claims. This does not supercede or interfere with the need for primer with topcoat--and tiecoat where needed--but addresses layers within each function. Coatings companies are working toward technology that reduces layers and total DFT (dry film thickness) for competitive advantage with more or less success. Sometimes abrasion resistance can be enhanced the same way, proving that what happens at these interfaces carries over into other properties.

From VCBud Jenkins of CSCS on March 8, 2011:
The theory is that perms are time dependent and successive coats will not affect permeability unless they are of lower permeability. I think I should assign this project to a student at Cal Poly Pomona Paint Lab to see if it really is true or not.

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

Built for Tough Jobs
From Epoxies to Urethanes to other high solid coatings, the new Binks Airless 75 delivers a great finish using an ergonomic design. Visit binks.com for more information.

LS Blasters: Optimum Steel Cleaning Efficiency
Simplify surface prep with the precise shot control of LS Blasters. Our blast technology delivers optimum coverage and finish. 800-533-8008

There’s only one CorroCote
Madison invented CorroCote
in 1974 to prevent corrosion
in underground fuel storage
tanks. Today, it’s still the
classic coating for protecting
infrastructure

See the difference immediately Black Magic®
Quality blast abrasive goes farther. Use Black Magic® The Tough Stuff coal slag. Cleaner, consistent, less dust. Order yours today!
Abrasives Inc. 800-584-7524

EnTech Dust Collectors in Stock & Ready to Ship
2,000 cfm to 80,000 cfm Units
Diesel * Electric * Bi-Powered
* Mobile Trailer Mounted
* Custom Designs and Colors
Find a Dealer near You
Call 1-800-733-5384

Moisture problems in your air lines?
Van Air Systems' Blast Pak is a portable compressed air drying system that reduces downtime in all blasting and coating applications.

www.USZINC.com

The Technology Publishing Network