PaintSquare.com
Follow us on Twitter Follow us on LinkedIn Like us on Facebook Follow us on Instagram
Search the site

 

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 MMI Tank 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

Advertisements
 
DeFelsko Corporation
 
PosiTector SHD Shore Hardness Durometer
 
PosiTector SHD measures the hardness of non-metallic materials. Features a measurement timer, auto ignore mode and internal memory. Shore A or D available.
 

 
Detail Masters
 
Overspray Removal
 
We offer professional, turnkey service and unparalleled quality!
Our process can save hundreds— even thousands of dollars. It's fast, environmentally safe and 100% guaranteed.
 

 
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.
 

 
Carlisle Fluid Technologies
 
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.
 

 
HoldTight Solutions Inc.
 
NO FLASH RUST - NO CONTAMINANTS
 
Our HoldTight®102 salt remover & flash rust
preventer prevents flash
rust by removing surface contaminants. Contact us
for your nearest distributor.
(800) 319.8802 sales@holdtight.com
 

 
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.
 

 
Industrial Vacuum Equipment Corp.
 
Hurricane Vacuums
& Dust Collectors
 
Vacuum and dust collector hose, filters and related accessories.
IndustrialVacuum.com
 

 
Clemco Industries Corp.
 
Maximum Dust Suppression Systems Start at $14,950
 
The system comprises proven technology and equipment with user-friendly flexibility in mind. See it in action.
 

 
SSPC: The Society for Protective Coatings
 
http://www.sspc.org/
 
Join SSPC and Enhance
Your Career !
 

 
 
 

Technology Publishing Co., 2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951

TEL 1-412-431-8300  • FAX  1-412-431-5428  •  EMAIL webmaster@paintsquare.com


The Technology Publishing Network

Durability + Design PaintSquare the Journal of Protective Coatings & Linings 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