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


Download our free ebook on Advances in Corrosion Control Coating Technology

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 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

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 for more information.

Sika® Industrial Floor Coatings

Click to learn about floor and wall systems relied upon for performance, durability, easy maintenance and aesthetics across the every industry and environment.

Novetas Solutions
Number 1 Crushed Glass Abrasive in America!

Manufactured from 100% Recycled Glass.
NO Crystalline Silica,
Beryllium & Arsenic
Great White Metal Finish!
4 plants on Navy QPL
Call us at 866-775-6226

N.T. Ruddock Co.

Our Abrasives Hold Up Under Pressure

N. T. Ruddock focuses on abrasive selection, equipment evaluation, equipment maintenance & reduction of abrasive consumption. Other services include Screen Analysis & Background Radiation Testing.

Nationwide Overspray
Profession Overspray Removal Services

The Finest Name in Safe Overspray Removal. We specialize in removing all contaminants from any surface. Family Owned and Operated for 33 years! Fully insured. Satisfaction is guaranteed.

Montipower, Inc.
The MBX Bristle Blaster

Get a 2.7 to 3.3 mil profile and a Near White Metal Clean. For info visit or call 877 629-8777

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.

Vector Technologies Ltd.
The Original Performance Proven Vacuum Solutions

Vecloader DV 145, 350hp 6200 CFM & 28’’hg. For those big jobs, choose Vector for the most powerful trailer mounted vacuum in the industry today. 800-832-4010, 414-247-7100.

W Abrasives - Surf Prep Pack

Experts in surface preparation are not working only on greens. To discover the SURF PREP PACK dedicated to experts. Visit our website,

New resins from BASF will have metals loving water:

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

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