PaintSquare.com


The First Word in Protective & Marine Coatings

A Product of Technology Publishing / PaintSquare
JPCL | PaintSquare News | Durability + Design | Paint BidTracker

Resource Guide Extreme Temperatures

Problem Solving Forum

| More

January 16 - January 22, 2012

When and why would I need to stripe coat if I’m using an edge-retention primer?



More items for Coating Materials


Selected Answers

From Kiran Pawar of Berger Paint Bahrain on January 18, 2012:
I am in total agreement with Brian.

From M Ehab of North Valley on March 21, 2012:
When? Whenever there were edges to get enough film thickness. Why? Because edges, rivets and so on are main corrosion spots and cost much more to repair.

From Tom Schwerdt of Texas Department of Transportation on January 18, 2012:
     I have seen numerous "edge-retentive" coatings which had an edge thickness half that of nearby flat areas. Some are better, some are worse. Non-edge-retentive coatings may be down at 25% of the thickness of nearby flat areas. In addition, there is not a good way of verifying edge thickness in the field. (Lab testing requires cutting through the substrate, mounting and polishing a section.) Magnetic gauges, ultrasonic gauges and even the PIG (Tooke gauge to some of you) are not good choices. Even if you do have an edge-retentive primer which works at 100% of flat thickness when properly applied, your field inspector cannot verify the thickness of the coating at the edge. Your inspector can visually verify the presence of a stripe coat.

From richard d souza of stoncor middle east llc on January 17, 2012:

     Regardless of the type of primer, a proper specification should include stripe coating of each of the subsequent coats to make sure the edges or weld seams receive enough coating film thickness to ensure longetivity of the coating system. Primer alone will not protect the surface from failure, and 80% of coating failures occur at these critical areas. And, usually, every coat should be followed by a stripe coat until you reach the finish coat, in  which case the stripe coat using the finish coat should precede the finish coat application.     

     If possible, the stripe coat should be tinted a color different than the main coating and must be brush- or roller-applied, depending on the job size and accessibility.

From Brian Chapman of Cadillac Fabrication on January 17, 2012:
     Stripe coating serves more than one purpose. Edge retention is just one of the many possible reasons for using this technique. Added protection on stitch-welded areas, tight corners or radiuses and irregular surfaces such as welds and flame-cut edges is provided by stripe-coating to ensure adequate coverage.

From Mark Edmonds of Vigor Shipyards Inc. on January 18, 2012:

     Your use of the word "primer" could infer an additional coat of paint is to be applied, perhaps for cosmetic purposes or an additional coat of protective coating. In the world of US Navy tank coatings, edge-retentive paints do not use the word "primer." The US Navy does in fact allow single coats of edge-retentive paints without a stripe coat. The caveat is that you have to take additional DFT readings to confirm the edges have the specified millage, usually 20-30 mils dft.

      This method of application and checking has many years of research data along with in-service data on board US Navy vessels/tanks to back up not having to apply a stripe coat. For reference see mil spec MIL-PRF-23236 Type VII and NAVSEA Standard Items 009-32 FY 12 (Chg 1) Note 23 and 24.

From George Musterer of Hecate Painting & Sandblasting on January 18, 2012:
     Wet films tend to back away from edges during curing as the film shrinks, leaving thinner cured material at the edges. That is the main purpose behind developing edge-retentive primer. The two main purposes of stripe coating are to get coating to areas that cannot be accessed or have limited access to spray application, behind bolts, rivets, threads etc. Another purpose is to break surface tension. When spraying, paint/coatings are not always in a hurry to flow into cracks, crevices, etc. due to surface tension. Using a brush will break the surface tension and force the paint/coating into those cracks & crevices, sealing up potential points of entry for moisture/water/electrolyte.

Please sign in to submit your answer this question    

Tagged categories: Primers; Striping


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

Sherwin-Williams
Heat-FLex® Hi-Temp 1200

Improved Corrosion
Resistance
Enhanced Durability
Faster Shop Throughput


BASF
New resins from BASF will have metals loving water:

Excellent corrosion resistance, low VOC, high gloss, thin films basf.us/industrialcoatings
polyorders@basf.com
800-231-7868


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.


Wasser High-Tech Coatings Inc.
Wasser Coatings Protect

some of the most important bridges in the country; learn about our NEPCOAT-approved system and our entire range of MCU & Polyurea coatings. 1-800-627-2968 www.wassercoatings.com


Polyval Coatings
Polyflex® Polyurea Linings

exhibit outstanding versatility in use; providing abrasion resistance, superior seamless waterproofing and high-chem corrosion protection. www.polyflexlinings.com


International Paint LLC

International Paint Engineered Coatings

Learn about our solutions for:
  • Structural Steel
  • Piping & Equipment
  • Storage Tanks
  • Pressure Vessels
  • Secondary Containment


    PreTox Products - NexTec, Inc.
    GOT LEAD? Specify Pretox System products

    The ONLY Lead Stabilizer Compatible with All Paint Removal Methods. Works with all Blast Media: Grits | Recyclable Abrasives | CO2 | Water | Power Tools | Etc. Call Dave Steffen at 800.338.8296.

  •  
     
     
    Technology Publishing

    The Technology Publishing Network

    The Journal of Protective Coatings & Linings (JPCL) PaintSquare
    Durability + Design Paint BidTracker JPCL Europe

     
    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 2000-2014, 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