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

 

Advertisement

PaintSquare


Problem Solving Forum

| More

October 14 - October 20, 2013

How do you prepare flame-cut edges for application of thermal spray metallic coatings? The problem is that these edges are often harder than the abrasive, so a very low profile is produced, resulting in lower-than-specified adhesion of the thermal spray to the steel.

More items for Coating Application


Selected Answers

From Ken Gray of TayMae Associates Inc. on October 17, 2013:
I would agree with David Shaw's response. Using a hard abrasive such as aluminum oxide  will aid in profiling the edges.

From Simon Hope of Bilfinger Salamis on October 16, 2013:
The normal option for this issue is to remove the heat-affected area, which is effectively a case-hardening due to the melting and flash cooling of the flame-burnt edge. Grinding is slow and laborious but is the most common method for this type of remedial action. As was previously mentioned by Dave Shaw, the need for 2 mm minimum radius is also imperative, not just for TSA but for any coating. Flame-cut edges have been a bane of the coating industry for years, and one or the easiest solutions is to move away from the use of oxy-propane gas cutters and go with a cold cut method such as UHP water with entrained fine abrasive, which removes the case hardening problem along with the need to remove it as well as taking away the known risk of crack nucleation from burnt edges due to the stresses, irregularities and brittle failure potential.  All a cold cut requires is edge radiusing. Expensive and more complex, maybe, but the end result is worth every penny if you can remove a potential failure risk!

From Giuseppe Santagata of NACE Certif. Coat. Insp. level III # 2737 on October 15, 2013:
Flame cut edges are very hard surfaces. Even if you try to have a certain blasting profile, you obtain a very poor anchor profile. TSA need a coarse profile between 80 and 100µm for a proper bonding. These surface will be ground properly until the hard layer is removed, and after, blast cleaned with a correct abrasive media and blasting technique.

From David Shaw of Barrier Fire Protection Ltd on October 15, 2013:
First, these edges must be suitably dressed by grinding to remove the surface and any remnants of 'flutes', and to provide the minimum radius of 2 mm on edges. Previous experience shows that these specific areas must be re-blasted with a very hard abrasive, such as aluminium silicate or aluminium oxide. My opinion is even chilled iron will not prepare these areas correctly because it's all due to the 'case hardening' process during the flame cut. Hope my contractor's perspective assists.

From Royce Gardner of CH2MHill on October 14, 2013:
Utilize a larger grit or steel shot to achieve the required anchor profile.

Please sign in to submit your answer this question    

Tagged categories: Galvanized/thermal spray coatings; Paint application


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

Advertisements
 
CS Unitec
 
Remove Coatings, Corrosion & More!
 
For metal & concrete. Scalers, scabblers, deck hammers & scarifiers. Safe for hot work zones. Call our specialists: 800-700-5919.
Demo videos at www.csunitec.com.
 

 
Waterjet Technology Association (WJTA)
 
Click to register today!
 
See the latest automated and handheld UHP waterblasting tools/systems/products. Exhibits, live demos, educational sessions, waterjet short course, networking.
 

 
SEMicro Division, M.E. Taylor Engineering, Inc.
 
Coatings Adhesion Testers
 
The PATTI® accurately measures the bond strength between coating & substrate. Outfitted properly, the surface can be rough, porous, or curved & >10K psi strong!
 

 
SAFE Systems, Inc.
 
Custom blast rooms
by SAFE Systems
 
Don't waste time and money "making do" with a "standard" design. Let us work with you to design and build the system that best fits your requirements.
Call 1-800-634-7278
 

 
Fischer Technology Inc.
 
DUALSCOPE®FMP100 with DataCenter IP
 
Transfer customized inspection plans from PC to FMP100 using step-by-step guidance with prompts and pictures throughout the measurement procedure
 

 
Vector Technologies Ltd.
 
The Original Performance Proven Vacuum Solutions
 
VecLoader® 616 Double Dump, Continuous Vacuum, 170 HP w/ 2,400 CFM & 28” Hg. 33% More Efficient than traditional vacuum systems! Choose Vector for the most powerful and the most reliable trailer mounted vacuums in the industry! Email us at: inquiry@vector-vacuums.com or call us at: 800-832-4010
 

 
Tarps manufacturing, Inc.
 
QUALITY MADE IN AMERICA —Available near you!
 
CLICK to get a behind-the-scenes look at how Tarps Manufacturing makes the highest-quality tarps right here in the USA — available nationwide.
 

 
Tnemec Company, Inc.
 
Online Coating Courses from Tnemec
 
For decades, Tnemec has offered its expertise to clients presenting face-to-face coatings courses. Now, these presentations are available to anyone for CEUs at Tnemec University.
 

 
KTA-Tator, Inc. - Corporate Office
 
KTA-TATOR LABORATORY SERVICES
 
• Coating failure analysis
• Independent testing
• Accelerated weathering testing
• Abrasives Testing
• Oil & Gas Material Qualification
• A2LA Accredited
Contact: Rob Leggat at
412-788-1300 x180
 

 
Aggreko
 
Dehumidification, Power and Temperature Control Rentals
 
Aggreko offers rental solutions for your painting/coating project. Dehumidifiers, cooling, heating, power and 24/7 service, nationwide.
844-433-9802
 

 
 
 

Technology Publishing Co., 1501 Reedsdale Street, Suite 2008, Pittsburgh, PA 15233

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