| Connect Follow us on Twitter Like us on Facebook
About | Subscribe | Advertise


Download the latest free Blasting Resource Guide eResource Book

Problem Solving Forum

| More

August 18 - August 22, 2014

How do you measure wet film thickness on shop-applied organic zinc-rich primers to accurately predict dry film thickness? Our shop applies a great deal of OZ primer, and we have found that WFT readings with a standard gauge are not accurate predictors.

More items for Quality Control

Selected Answers

From Larry Muzia of Exceletech LLC on August 22, 2014:
 The wet gage measurement is not exactly accurate  because the metallic zinc particles do not allow the two ends of the gage to make direct contact with the substrate. They are a solid, and if zinc is under the edge, it will prove to be inaccurate. The is the case with both organic or inorganic zinc filled coatings. I agree that an agitated pot or very low speed agitator in the bucket if spraying airless is a must. Remember to keep the speed low to avoid inducing a vortex sucking moist air into the product if the humidity is high. As for accurately measuring the wet film, the use of a wet film gage will give you an approximate reading, although it will not be 100 % accurate. Experience is never out of style, and, typically, these materials dry within hours, allowing a confirmation using a dft gage.

From Steve Brunner of WPC Technologies on August 19, 2014:
I find it odd that a wet film gauge does not yield accurate predictions. Given that, I recommend consistency and a practice board. On the former, thinning the same to a consistent viscosity will keep the solid content nearly identical from batch to batch. Then use a practice (pattern) board for the applicator to determine gun pattern, adjust the application equipment and helps out the applicator with the arm speed. I have seen a lot of applicators who use practice/pattern boards and always end up being spot on with the DFT. The last issue is use of an agitated pot. It has been my experience that zinc-rich coatings will settle in rapidly, thus the need to keep agitated. If not agitated, the coating will have an inconsistent solids content.  On this last thought, this could be the problem and the easiest fix.

Please sign in to submit your answer this question    

Tagged categories: Coating / Film thickness; Dry Film Thickness (DFT); Wet film thickness

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

HoldTight Solutions Inc.

Our HoldTight®102 salt remover & flash rust
preventer prevents flash
rust by removing surface contaminants. Contact us
for your nearest distributor.
(800) 319.8802

DeFelsko Corporation
PosiTector Inspection Kits

PosiTector 6000 Coating Thickness Gage easily converts to a surface profile gage, dew point meter or ultrasonic wall thickness gage with a simple probe change

Desco Mfg. Co., Inc.

Steel Fabrication

• Shipyards
• Plate Fabrication
• Structural Steel
• Maintenance

DESCO Mfg.Co., Inc.

Novatek Corporation
Novatek Corporation, Dustless Coatings Removal

Strip, clean and profile all dust free! Comply with new lead standards. Contact today: (866) 563-7800

KTA-Tator, Inc. - Corporate Office
Coatings Inspection

Any structure, any height, any place - A qualified coatings inspector is always available. Call 1-800-245-6379.

Fischer Technology Inc.

Paired with the PHASCOPE PMP10, Fischer’s new probe is quick and accurate for measuring thermally sprayed aluminum on stainless steel. Click to learn more.

SAFE Systems, Inc.
Enduroguard -
The Tough Cable
for a Tough Industry.

Reduce maintenance costs and down time, increase job site safety with Enduroguard Cable. Available exclusively from SAFE Systems. UL listed, flexible, abrasion resistant and cut resistant.

Avalotis Corporation
Choose experience. Choose quality. Choose safety.

Avalotis Corporation has been meeting and exceeding clients’ specifications and expectations for almost 50 years. The first name in painting and protective coatings: Avalotis.

Industrial Vacuum Equipment Corp.
Hurricane Vacuums
& Dust Collectors

Vacuum and dust collector hose, filters and related accessories.

CS Unitec
Remove Rust, Paint and More!

Remove coatings, corrosion & produce keyed surfaces with CS Unitec's floor planers. 8" & 10" cutting width. Gas, air & electric models.

Technology Publishing

The Technology Publishing Network

The Journal of Protective Coatings & Linings (JPCL) PaintSquare
Durability + Design 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   |   Site Map   |   Search   |   Contact Us

© Copyright 2000-2016, Technology Publishing / PaintSquare, All rights reserved
2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951; Tel 1-412-431-8300; Fax 1-412-431-5428; E-mail