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

 
 

 
Novatek Corporation
 
Dustless Coatings Removal
 
Novatek Corporation, Dustless Coatings Removal Strip, clean and profile all dust free! Comply with new lead standards. Contact today: (866) 563-7800 www.Novatekco.com
 

 
SAFE Systems, Inc.
 
Enduroguard -
The Tough Cable
for a Tough Industry.
 
Reduce maintenance costs and down time, increase job site safety with Enduroguard Cable. Available exclusively from SAFE Systems. UL listed, flexible, abrasion resistant and cut resistant.
 

 
Fischer Technology Inc.
 
FISCHER Expands Corrosion Product Line
 
Rounding out Fischer’s extensive line of products for measuring protective coatings in the corrosion industry is the new ultrasonic wall thickness gauge UMP series.
 

 
NLB Corporation
 
NLB Sure Shroud: Greater Protection and Flexibility
 
NLB’s Sure Shroud’s lighter weight and flexibility reduces operator fatigue and offers unmatched protection against high pressure hose ruptures. 10k to 40k psi rated.
 

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

 
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.
 

 
US Minerals
 
Blast with the best
 
The most effective blasting media on the market, Black Diamond hits harder and cleans faster.
 

 
Jotun Paints Inc.
 
Jotun Jotachar 1709
 
Mesh-free passive fire protection epoxy designed to protect against hydrocarbon pool fire scenarios for up to four hours as defined in the ANSI/UL1709 standard.
 

 
 
 

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   |   Support   |   Site Map   |   Search   |   Contact Us