PaintSquare.com
      | Connect Follow us on Twitter Like us on Facebook
About | Subscribe | Advertise
  

 

Download our free eResource: Specifier's Choice Guide Download Now

Problem Solving Forum

| More

November 21 - December 4, 2011

How do you measure the DFT or WFT of a film-forming sealer applied to a metallized coating (e.g., flame-sprayed zinc)?



More items for Quality Control


Selected Answers

From Simon Hope of Bilfinger Salamis on November 30, 2011:

     The answer is in the question! For TSA (Thermal Sprayed Aluminum), we are looking to seal an inherently porous material. The sealer coat is there to fill the interstices but not to create any particular build. The amount of sealer applied is dependent on the level of porosity and thickness of the TSA as well as the solvent content of the sealer coat.

     Guidelines are given by manufacturer, but these are only ballpark figures to form the start point for application. Normally, a sealer is applied just enough  to create an apparent wet film, which will dry back into the profile as the solvent evaporates, thus coating the bare metal as well as providing a tie coat for subsequent higher volume solids coats. Consumption can, if required, be calculated in area per unit volume, and from that, it is possible to approximate to WFT and DFT, though, in reality for this process, these are pretty meaningless and the visual appearance is more relevant. Coating integrity is the primary objective, and a good applicator will produce the visually correct sealed substrate, which can be confirmed by the material consumption.

From Gunnar Ackx of SCICON worldwide bvba on November 22, 2011:
     You can't. A sealer for spray-metallizing is typically applied on visual observation. The idea is to just cover the spray-metallizing without actually building up an (entirely) closed film of paint over the spray-metallizing. Ideally, you will still see the surface roughness of the spray-metallizing, but not its color anymore. Also key to a good sealer-coat application is using the correct amount of thinning, so that the sealer-coat gets soaked into the pores of the spray-metallizing as well as possible. The amount of thinning will vary from one product to another and from manufacturer to manufacturer, and I've seen this vary between 5 and 50%. If you're not using enough thinner, then the sealer-coat will lay on top of the spray-metallizing, which will cause it to have much less adhesion and will likely still give you the typical 'popping phenomenon' (outgassing of the spray-metallizing), which is one of the main reasons why a sealer-coat is applied onto spray-metallizing.

From David Lemke of Team Industries, Inc. on November 21, 2011:
     I have used the theoretical coverage of the coating, which included an estimated transfer efficiency with the amount used. I gave the applicator a low and high amount of coating he could use for the square footage they were coating for the range of the DFT. I took the actual amount they used and plugged it into the formula to get the estimated DFT. Another way is to put a piece of substrate across the area to be coated and have the applicator spray the amount they thought would be correct across both the metallized coating and the piece of substrate. Wet mil the piece of substrate, and that should tell you if the thickness is on track to meet the DFT. If not, then you can adjust. The thing with both ways, you need to have an applicator who can consistently duplicate the application process to be effective.

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.
NO FLASH RUST -
NO CONTAMINANTS

Our HoldTight®102 salt remover & flash rust preventer prevents flash rust by removing surface contaminants. It has no equal; only wannabees.
Contact us for your
nearest distributor.
(800) 319.8802 sales@holdtight.com


Fischer Technology Inc.
MP0R with rotating display screen

Automatic rotating display screen just like your smart phone. Click for Video
Call 800-243-8417


KTA-Tator, Inc. - Corporate Office
KTA-Tator EH&S Services

• Ambient & Worker Exposure Air Monitoring
• Safety & Health Program Development
• Lead Paint Assessments
& Specifications
• Health Hazard & Jobsite Safety Assessments
Call 1-800-245-6379


DeFelsko Corporation
A Smart New Way to Measure

PosiTector SmartLink and free mobile app turns your cell phone or tablet into a virtual PosiTector gage.


Park Derochie Coatings Ltd.
www.ParkDerochie.com

Coatings          Fireproofing
Sandblasting     Scaffolding
Metalizing           Insulation

• Shop & Field Services
• SSPC Certified
• NACE Inspectors on staff
• New Construction &
  Maintenance Programs


Seymour Midwest
Coating Application Tools & Supplies

Visit our “Where to Buy” site to find a local paint or tool supplier near you. Click here for a chance to win $500 of Tools & Supplies. 1(844)739-6687 Sales@SeymourMidwest.com


DRYCO
Climate Control...delivered.

Temporary climate control equipment. Dehumidifiers,
Heaters, A/C, Power, More…
Call: 866-379-2600


Novetas Solutions
Number 1 Crushed Glass Abrasive in America!

Manufactured from 100% Recycled Glass.
NO Crystalline Silica,
Beryllium & Arsenic
Great White Metal Finish!
4 plants on Navy QPL
Call us at 866-775-6226


Clemco International GmbH
Global engineering-trusted solutions

For more than 70 years, Clemco has provided the highest quality blast equipment with a total commitment to comfort and safety.


Hempel (USA) Inc.
Wider range of Hempel Protective Coatings now approved by Norsok.

Proven high performance products that protect your assets. Contact us today at protective@hempel.com to find out more.

 
 
 
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 PaintSquare.com   |   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 webmaster@paintsquare.com