Why an Interest in EQ Coatings?

Transcription

1 EQ Coatings: Codes, Standards, and Corrosion Protection October 15 and 17, 2013 Presented by Bill Capizzano, President Chemcoaters, LLC & Eco Green Coatings, LLC Patrick Ford, P.E. Matsen Ford Design, Technical Director, SFIA Co Sponsors: Why an Interest in EQ Coatings? Metal stud manufacturers need to remain competitive Within the Metal Stud Industry Against alternative materials such as wood & concrete The Metals Industries desire to find stability in zinc premiums The Metal Studs Industry s ability to utilize abundant excess Automotive HDG/Galvanneal/EG to lower costs EQ Coatings have significantly shown to outperform standard metallic coatings such as; G40 HDG and A40 Galvanneal G60/G60 Electro galvanized GF30 Galfan 1

2 What are EQ Coatings? EQ Coatings were developed to provide equivalent or superior corrosion protection compared to approved metallic coatings that are listed in Table 1 of the ASTM A1003 standard. EQ Coatings allow stud manufacturers to utilize Automotive excess metallic coated substrates. Automotive metallic coated substrates are manufactured to the highest quality Metal stud manufacturers have invested millions of dollars to post reduce this commodity, therefore increasing yields and reducing weight. This correlates to a cost savings back to the customer and end user, in addition to LEED credits. The concept of utilizing higher strength steel and reducing gauge is not new to the metal stud industry. The Automotive, Truck, Trailer, Appliance, HVAC, Garage Door and other business segments embraced this concept for years Interior Drywall Steel Stud Framing Codes and Standards Requirements The IBC 2012 (earlier editions are similar): Referenced in several locations, but the applicable requirements for drywall stud framing is: Chapter 25 GYPSUM BOARD AND PLASTER Table Gypsum Board Materials and Accessories Table Installation of Gypsum Construction 2

3 Codes and Standards Requirements (continued) Referenced Standards: Per Table ; ASTM C a Specification for Nonstructural Steel Framing Members Per Table ; ASTM C Specification for Installation of Steel Framing Members to Receive Screw attached Gypsum Panel Products Codes and Standards Requirements (continued) Additional standards referenced in C645 and C754: ASTM Specs: A653 (galvanized and galvannealed); A1003 (general sheet steel spec for use in CFS members metallic or nonmetallic coated) AISI Specs: S100 (North American Spec); S202 (Code of Standard Practice) ICC ES: AC86 (Acceptance Criteria for Interior Walls) 3

4 Codes and Standards Requirements (continued) Standards relative to the protective coating on steel used for the framing members (referenced in the foregoing standards): ASTM Specs: A1004; Practice for Establishing Conformance Minimum Corrosion Characteristics B117; Practice for Operating Salt Spray Apparatus Protective Coating Requirements The IBC defers to the industry standards, as does ICC ES; AISI standards do not address the coating requirements as of yet Among the dozens of ASTM standards, the key ones that are applicable to EQ coatings are: C645; Per Section 4.2: Members shall have a protective coating conforming to Specification A653 G 40 minimum or shall have a protective coating with an equivalent corrosion resistance, Note this equivalent provision has been in the standard for over 20 years 4

5 Protective Coating Requirements (continued) Other applicable ASTM Standards: A1003; Per Sections for Metallic Coated Sheet Steels; ; No more than 10% loss of coating at the end of the prescribed test duration ; Minimum exposure for type NS steels is 75 h. A1004; Per Section 6.2 Procedures for Metallic Coated Products; 6.2.1: Use Practice B117 to evaluate conformance Protective Coating Requirements (continued) These standards and requirements have been adopted into the SFIA QC program. In short, the requirements for a Metallic G 40 Equivalent coating are: The manufacturer must show that EQ coating is more than 50% metallic It must submit to B117 Salt Spray tests per the listed protocols and sample quantities It must pass the ASTM required 75 hour minimum test duration with less than 10% coating loss (i.e.: relative area of red rust) 5

6 Summary: Codes and Standards Requirements For Drywall Framing, The IBC Code refers to ASTM standard C645 Relative to Equivalent Coatings The other Standards referenced in turn are: ASTM A1003; ASTM A1004; and ASTM B117 These standards are adopted into the SFIA QC program and serve as the basis for performance requirements in the program. How do EQ Coatings Work? EQ Coatings are primarily (or entirely) comprised of metallic compounds and are highly conductive. EQ Coatings require a zinc, zinc alloy or zinc iron alloy metallic coated substrate to effectively work. EQ Coatings are NOT BARRIER coatings, unlike TFA s, primers and/or prepaints. EQ Coatings covalently bond, they integrate into the zinc, zinc alloy or zinc iron alloy metallic coated substrate and become a singular composite coating system. It is this characteristic, that provides the tremendous corrosion resistance properties. In some EQ Coating systems, cut edge and scratch resistance is so enhanced over standard metallic coating systems that some EQ Coatings can provide self healing characteristics. 6

7 How do EQ Coatings Work? (Cont d) Depending on the original metallic coated substrate and the minimum metallic coating weights (mass), cold formed NS members utilizing EQ Coatings have performed significantly better than studs that strictly utilize the approved metallic coatings that are listed in Table 1 of the ASTM A1003 Standard. Examples; Typical G40 HDG or A40 Galvanneal metallic coated substrates that are manufactured according to the ASTM A653 Standard for Galvanized Sheet Steel, are assumed to have.40 oz./ft² (total for both sides) of coating weight (mass). In closer review of the standard, the actual coating weight can be as low as.12 oz./ft² on a single side. Also, the surface of the galvanizing process can create vast valleys, fractures, pits and porosity in the zinc, zinc alloy or zinc iron alloy metallic surface. How do EQ Coatings Work? (Cont d) Picture taken from a SEM slide at 6,000 x magnification, notice the inconsistent surface in the metallic zinc layer bonded to the base CRS substrate. Again, notice the valleys, fractures, pits and porosity in the zinc surface. This explains the typical corrosion variances that one can see in batch to batch of zinc metallic coated substrates, which we will understand better from next slide. 7

8 How do EQ Coatings Work? (Cont d) To the left are several G40 HDG NCT control standards at varying coating weights. All panels are within the approved and allowable coating weight range of Table 1 in the ASTM A653 standard for Zinc Coated Steel Sheet. All shown G40 control standard test panels were tested in accordance with ASTM B117 Salt Spray testing. Lighter levels of zinc metallic coating weights hit 10% red rust in less than 75 hr., far below the ASTM A1003 required corrosion level. Mid to heavier coatings weights made the standard of less than 10% red rust, but all coating weight ranges were heavily white rusted even at 48 hr. How do EQ Coatings Work? (Cont d) To the left are a set of G40 HDG control standards and a set of A40 Galvanneal control standards. Both sets of panels are within the approved and allowable coating weight range of Table 1 in the ASTM A653 standard for Zinc or Zinc Iron alloy Coated Steel Sheet. All G40 and A40 control standard test panels were tested in accordance with ASTM B117 Salt Spray testing. It is easy to see that even though the A40 GA panel is an approved metallic coating listed in Table 1 of the ASTM A1003 standard it does not meet the required 75 hr. corrosion test duration. 8

9 Performance of EQ Coatings EQ Coatings are applied on a precision, digitally controlled chemcoater utilizing a reverse roll coating process. The EQ Coating is precisely applied so that the repeatability and consistency of coating is very uniform, and then cured with an IR Oven at F. In further review of the SEM slide, previously shown, the surface of the EQ Coating is very flat and consistent, much like the CRS base substrate. Notice the valleys, fractures and pores have been effectively filled in with the EQ Coating, part of this effect is from the immediate cure by heat. This process is the reason why EQ Coatings perform so well, as compared to, the non EQ Coated zinc, zinc alloy or zinc iron alloy metallic substrate. Performance of EQ Coatings (Cont d) To the left are audit test panels taken from a production run of a stud manufacturer utilizing Automotive excess A40 GA. Coils were coated with InterCoat ChemGuard 615 (an EQ Coating). Coils were then post reduced after coating by 26%, slit, and then roll formed into finished studs. All test flat panels, formed studs and G40 control standard test panels were tested in accordance with ASTM B117 Salt Spray testing. G40 control standard hit 10% red rust within 72 hr., just below the ASTM A1003 required corrosion level. All audited panels (flat and formed studs) had no red rust and very little white rust at 120 hr., far exceeding the ASTM A1003 required 75 hr. equivalency. 9

10 Performance of EQ Coatings (Cont d) To the left are audit test panels taken from a production run of a stud manufacturer utilizing Automotive excess Electrogalvanized. Coils were coated with InterCoat ChemGuard 615 (an EQ Coating). Coils were then post reduced after coating by 23%, slit, and then roll formed into finished studs. All test flat panels, formed studs and G40 control standard test panels were tested in accordance with ASTM B117 Salt Spray testing. G40 control standard hit 10% red rust within 100 hr., exceeding the ASTM A1003 required corrosion level of 75 hr. All audited panels (flat and formed studs) had no red rust and almost no white rust at 168 hr., far exceeding the ASTM A1003 required 75 hr. equivalency. Performance of EQ Coatings (Cont d) The photo on the upper left shows audit test panels taken from a production run of a stud manufacturer utilizing Automotive excess A40 GA. Coils were cold reduced and then coated with InterCoat ChemGuard 315 (an EQ Coating). Coils were then slit and flat samples taken from the slit mults. All test panels & G40 control standard test panels were tested in accordance with ASTM B117 Salt Spray testing. Look closely at the EQ Coating scribe at 96 hr. vs. the G40 HDG scribe at only 24 hr. in salt spray. 10

11 Other Advantages of EQ Coatings EQ Coatings formulations can be modified to meet the needs of many specialized requirements or applications, such as; Hexavalent Chromium Product Trivalent Chromium Product (RoHS Compliant) Chrome Free Product (RoHS Compliant) Lubricity additives can be added that would increase the formability through the roll formers, therefore improving productivity, increasing tool life and reducing the level of wet lubricants used. All this would effectively help in reducing the overall cost to the consumer. Other Advantages of EQ Coatings (Cont d) In accordance with the ASTM A 1003 Standard; Not all coatings will react the same under a given set of environmental conditions. These minimum coating designations assume normal exposure conditions and construction practices. When more severe exposure conditions are probable, for example, in coastal areas, consideration should be given to specify heavier coating weights (mass). In other words, G60 or G90 should be specified in these severe applications. EQ Coatings can easily accommodate this requirement at a fraction of the cost as compared to zinc premiums over G40. 11

12 Other Advantages of EQ Coatings (Cont d) Since Sept. of 2011, when InterCoat ChemGuard s current EQ Coating formulations were finalized and tested, Eco Green Coatings and Chemcoaters has processed the following linear feet of NS studs without a single reject for corrosion in the field; over 75,000,000 LF of studs were EQ Coated with InterCoat ChemGuard 615. Coils were cold reduced after coating, slit and then roll formed into NS studs. Over 110,000,000 LF of studs were pre reduced, then EQ Coated with InterCoat ChemGuard 315, slit and then roll formed into NS studs. Other Advantages of EQ Coatings (Cont d) Though EQ Coatings were designed for the Stud Industry, other industries have accepted the coatings due to outstanding corrosion performance. Some of these applications include; Transportation; current large vehicle manufacturer has specified InterCoat ChemGuard 325 into the floor of their vehicles. They now offer 10 year warranties over the traditional 5 year warranty. US Steel mills are discussing the use of InterCoat ChemGuard 315 to eliminate transient rust when coils are shipped from the Midwest to Mexico. Ceiling grid manufacturers are currently testing G30 coated with InterCoat ChemGuard 315 to replace G90. Major US Appliance manufacturer is testing InterCoat ChemGuard 315 to improve corrosion issues in dishwashers. Major HVAC manufacturer utilizes InterCoat ChemGuard 315 as a Hybrid Primer for roof top units to improve corrosion protection. Major US Door manufacturer testing InterCoat ChemGuard 315 to improve corrosion and reduce field corrosion claims. 12

13 EQ Coatings Questions & Answers 13