PaintSquare.com


The First Word in Protective & Marine Coatings

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

Problem Solving Forum

| More

June 22 - July 6, 2010

I have several water tanks constructed with carbon steel for demineralized water storage. The tanks are about 20 years old, and the original coating has started to blister. For refurbishment of the coating, what material should be used and at what dry film thickness? The original type of coating is unknown.


Selected Answers

From Ted MacMillan of Brant Corrosion Control,Inc. on June 25, 2010:
There are several questions that need to be answered prior to making a proper recommendation for this service, or which path to take with repair of the existing system. If the blistering is extensive, the lining needs to be replaced, if it's minor blistering, chances are the system can be repaired; however, you will have to constantly monitor it during your maintenance program (yearly). Depending on the type of coating system that was applied and the original DFT of the system, you should be able to determine if that particular coating performed the way it was intended to for the service. If the material was a thin film coating, say 10-12 mils, then getting 20 years of life in demineralised water service was a success. If the coating was not maintained regularly, you did exceptionally well. As previously stated by others, demineralised water is very aggressive, and selecting a replacement system should be based on the full operating parameters of the actual service. Our company has installed several systems for these services ranging from thin films to rubber lining. The success of any lining will be dependent on the condition of the existing structure, cleaning to remove contaminants, blast cleaning, application, curing, and final inspection prior to placing the equipment back into service.

From Pieter van der Poel of Danieli Far East on June 23, 2010:
I think you are having a problem with osmotic blistering caused by the demineralized water. Demineralized water tries to absorb minerals, salts, etc., to achieve an equilibrium. This could come from a contaminated substrate sealed by the membrane (this being the existing coating). If the coating has been in service for the last 20 years, it has performed well, especially if localized repairs had been carried out during regular inspection intervals. A coating manufacturer could recommend a lining suitable for the type of service, but wet service temperatures also play an important factor in its selection. Whatever the lining used, it should be impervious to the maximum extent for this type of service. Surface preparation to SSPC-SP 10 and, most important, salt testing should be carried out to avoid future problems with osmotic blistering. The coatings manufacturer will most likely recommend a solvent-free epoxy lining, perhaps even with glass flake. Depending on the extent of blistering, it should be decided whether to go for complete refurbishment as you already stated in your question or to go for spot repairs. Take into consideration any factors related to CP.

From Chuck Pease of PCG on June 23, 2010:
At this time there isn't enough information to answer your question. A couple of things need to occur before a solution can be offered. First question in determining the answer: is the coating you speak of interior or exterior or both? The next thing would be to determine if the existing blistered coating will need to be abated, and more importantly, is it a lead-bearing coating. If the coating is only blistered in various areas but the remainder of the coating is tightly adhered, then one can determine if a surface prep and an overcoat would be appropriate. If the coating is lead-bearing and lossely adhered all around, these factors would suggest complete abatement and prep of steel to SSPC- SP 10 prior to choosing a coating system.

Please sign in to submit your answer this question    


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

DRYCO
The one way to control
a tank: DRYCO

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


Bullard

The Next Generation
of Blasting

• Lightest
• Coolest
• Most Comfortable
• Most Dependable


Termarust Technologies
Termarust (HR CSA) Chemically Stops
Active Corrosion

Pipeline Utility Aerial crossings coated since 1992. Termarust's (HR CSA) was used to overcoat lead paint and preserve cables, pipes and support towers.


Spider, a Division of SafeWorks, LLC
Complete Suspended Access Solutions

Need Access? From platforms & hoists to rigging & fall protection, Spider leads the industry in rentals, sales & service.
Call today: 877-774-3370


Advanced Recycling Systems
ADVANCED RECYCLING SYSTEMS (ARS)

Recycling Machines, Dust Collectors, Rapid Deployment units are time-tested and approved for the rugged industrial environment. Contact ARS today!
(330)536-8210


ITW Binks
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.


Greener Blast Technologies
Reinventing the Blasting Industry

Greener Blast Technology, Inc. manufactures the most effective slurry blasting system available on the market to date.

 
 
 
Technology Publishing

The Technology Publishing Network

The Journal of Protective Coatings & Linings (JPCL) PaintSquare
Durability + Design Paint BidTracker JPCL Europe

 
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 2000-2014, 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