PaintSquare.com
      | Connect Follow us on Twitter Like us on Facebook
About | Subscribe | Advertise
  

 

Download our free Specialty Function Coating Systems eResource Book

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

Thermion Inc
Buy Back Program

We are offering $5,000
credit for your old Model
This drive system is
being discontinued by
the manufacturer.
More information at
thermioninc.com
877.884.3428


Mitsubishi Gas Chemical America
Performance Amine 1,3-BAC

A highly reactive cycloaliphatic diamine offering superior performance. Reasonable cost and curing efficacy makes it suitable for all types of epoxy resin applications.


Novatek Corporation
Dustless Coatings Removal

Strip it, clean it, and profile it,
all dust free! High production
rates and Blast like finishes.
Comply with new lead
standards.


Fischer Technology Inc.
MP0R with rotating display screen

View your coating thickness readings from any angle with rotating display screen. New graphic display with easy menu navigation. Click for Video
Call 800-243-8417


Armakleen Company, The
ARMEX when nondestructive cleaning is critical

The gentle physical propriety of baking soda but yet aggressive cleaning ability is what makes ARMEX the only choice for nondestructive abrasive blasting.


LS Industries
LS Blasters: Optimum Steel Cleaning Efficiency

Simplify surface prep with the precise shot control of LS Blasters. Our blast technology delivers optimum coverage and finish. 800-533-8008


Sidewinder/Persyst Enterprises, Inc.
The Sidewinder Model M2 Solvent Recycler

Combat the rising cost of gunwash, thinners, acetone & more while drastically reducing waste disposal coat.


Corrosion Probe, Inc.
From Detection to Correction

Corrosion Probe, Inc. has the Most Concrete Coatings Experience and Expertise. Contact us today at
860-767-4402, www.cpiengineering.com

 
 
 
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 PaintSquare.com   |   Privacy policy   |   Terms & conditions   |   Site Map   |   Search   |   Contact Us
 

© Copyright 2000-2015, 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