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


Download our free e-book! Corrosion Under Insulation. Sponsored by Thermion.

Problem Solving Forum

| More

April 30 - May 6, 2012

How do you determine whether a lead-bearing coating can be overcoated or removed and replaced?

More items for Coating Materials

Selected Answers

From Frank Rea of GPI-Southeast on May 1, 2012:

     To determine whether any coating can be overcoated or needs to be removed and replaced, one must first conduct an existing coatings condition assessment. The assessment consists of observations and tests which provide the data necessary to make the decision. A typical condition assessment begins with observing the type, amount, and distribution of rust and coatings defects. SSPC-Vis 2 is a helpful guide when making this determination. Typically, if the amount of rust exceeds 25% or is destributed randomly over several locations, full removal is likely because spot cleaning would be too labor-intensive and time-consuming.   

   Second, dry film thickness and number of coats should be measured with a magnetic DFT gage and a Tooke gage at random and representative locatons. There are only so many layers and a maximum total thickness that can be applied before risking failure. Next, utilizing ASTM D 3359 Methods A (DFT > 5 mils) or B (DFT < 5 mils), determine the adhesion rating. When overcoating, the new paint may shrink as it cures and put stress on the existing coating. If the existing coating is not tightly adhered, it may peel. Lastly, take sample of the paint and have the top coat analyzed by Fourier Transform Infrared Spectroscopy (FTIR) to verify the generic type of resin. This will allow the specifier to select a compatible overcoat material.

Please sign in to submit your answer this question    

Tagged categories: Lead; Overcoating lead

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

Sherwin-Williams General Polymers Resinous Flooring App

Our coatings and linings expertise available 24/7, allowing you to explore the Sherwin-Williams systems best suited for your flooring needs. Download the app today!

Carboline Company
Carboline is pouring with opportunities

We are proud of our exceptional products and services, and believe that people are our greatest asset. Come grow with us!

Mitsubishi Gas Chemical America
Performance Amine 1,3-BAC

A highly reactive cycloaliphatic diamine offering superior performance. Reasonable cost and curing efficacy makes it suitable for all types of epoxy resin applications.

PPG Protective and Marine Coatings Group
We Protect and Beautify the World

PPG is widely recognized as a world leader in protective and marine coatings, developing innovative, cutting-edge products and services.

Wasser High-Tech Coatings Inc.
Wasser Coatings Protect

Wasser Coatings offer a complete range of Moisture Cure Urethane (NEPCOAT approved) systems in addition to Polyurea membranes and linings(NSF).

Jotun Paints Inc.
Jotachar JF750 - The Time Saving Solution

The only mesh free solution for jet fire scenarios. Jotachar saves installation time and material costs - the next generation of epoxy passive fire protection.

New resins from BASF will have metals loving water:

Excellent corrosion resistance, low VOC, high gloss, thin films

Hempel (USA) Inc.
Trusted worldwide for advanced protective coatings

Trusted worldwide
for advanced
protective, coatings
–Full range of 
  advanced coatings
–Optimised application
–Fast, reliable service  worldwide. Contact us at

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

Desco Mfg. Co., Inc.

Steel Fabrication

• Shipyards
• Plate Fabrication
• Structural Steel
• Maintenance

DESCO Mfg.Co., Inc.

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