https://www.galvinfo.com/galvinfonotes/ Generally, the corrosion rate of hot-dip galvanizing in tropical seawater is much more corrosive than temperate seawater. This spray is set to fall-out on to the specimens at a rate of 1-2 ml/80 cm 2 /hour, in a chamber temperature of 35 C. Dallin cautions that roofs with low slopes are subject to the most severe corrosion conditions. Architecturally Exposed Structural Steel (AESS). In other words, the salt-spray test attacks the wrong material (zinc metal instead of the zinc patina) and therefore will give an incorrect prediction of the performance of the hot-dip galvanized coating in the real world. Statistic cookies help us understand how visitors interact with websites by collecting and reporting information anonymously. G40 is, galvanized with a two-sided coating weight of .40 ounces per square ft (oz/ft). This climate is maintained under constant steady state conditions. A time to first maintenance of 2-3 years is not uncommon for such applications. Continuous Sheet Galvanizing. Statistic cookies help us understand how visitors interact with websites by collecting and reporting information anonymously. Hot dip galvanizing is mainly used in corrosive environments, like corrosion category 2 to 5 acording to EN ISO 12944-2, but can also be used in less severe environments, for example indoors. What is the proper process if newly install galvanized ductwork with a G90 coating needed to be painted? William. (2) Generate zinc oxide and zinc hydroxide (and other substances) for 48 hours to 1 year. The contractor intends to use 6 sch 40 galvanized pipe for piling. A. 2023 American Galvanizers Association. Gary Dallin, PE, president of Steel Technology Services Inc., Burlington, Ontario, Canada, The Queens, N.Y.-based Rockaway Hotel was clad in resilient architectural zinc wall panels due to its proximity to the ocean. This is specifically referenced in ASTM B117, Standard Practice for Operating Salt Spray (Fog) Apparatus which also states correlation and extrapolation should be consideredonly in cases where appropriate corroborating long-term atmosphericexposures have been conducted: 3.2 Prediction of performance in natural environments has seldom been correlated with salt spray results when used as standalone data. Generally, such applications Salt Spray Resistance ASTM B117 5% Salt Fog 1000 hours exposure @95'F Scribe: Rating of 7 (1/16" creeapage) per ASTM D1654 procedure A 0000009715 00000 n Since the 1920s, hot-dip galvanized steel samples have been placed in thousands of different environments and the corrosion rate has been measured. 0000004990 00000 n Due to this, the Puget Sound region, with little breaking surf and rainfall of 42 inches is a less severe marine environment compared to the Southern California coast, with its strong breaking surf and less than 12 inches of rain per year. Ton: 3.5 Ton. If metal roofs or walls start to rust, they will not function as intended and will have to be replaced. Scope. Simpson Strong-Tie 2.099-in x 2.5-in x 3.974-in 12-Gauge G90 Galvanized Steel Angle. 1.2 This specification covers both unfabricated products and fabricated products, for example, assembled steel products, structural . Since the zinc carbonate is not formed, the salt spray interacts directly with the zinc metal. Each type of galvanized product, batch or continuous, has applications where it would be best utilized. 3.2.2 differentially coated, ngalvanized steel sheet having a specied "coating designation" on one surface and a signicantly . Both galvanized steel and Galvalume weigh 100 to 150 pounds per 100 square feet and contain about 35% recycled steel post-consumer content. The part corrodes very quickly when the salt spray attacks the zinc metal. Salt spray test abrades the oxide layer, so removing . The benefit of If you are looking for more information that discusses the differences between continuous and batch hot-dip galvanizing, download the AGA publication Zinc Coatings, which gives in-depth explanations of both processes (as well as the other zinc coating processes), and the one-page comparison sheet, General Hot-Dip Galvanizing vs. Salt-Spray/Fog Accelerated Corrosion Testing of HDG Steel. The salt spray test is the exposure of the surface coating to a fine mist containing 5% sodium chloride, for a given time, at room temperature. The information they store is not sent to Pixel & Tonic or any 3rd parties. Marketing cookies are used to track visitors across websites. . Striving to live Aloha If the corrosion rate and time to first maintenance for a specific project site is desired, a more accurate estimate may be obtained by inputting data such as average precipitation, average salinity, and average sulfur dioxide for the local area around the project site into an online model called the Zinc Coating Life Predictor. %PDF-1.4 Terms of Use HSLA Grades 40 - 80. Architecturally Exposed Structural Steel (AESS). }2a`;r,bIvebqv OaGk _v!X@ TP Terms of Use This steel is dull gray in appearance, has no spangle, and is well suited to painting. Following on from Ted's comments about salt spray testing. That oxide is removed in salt spray testing, exposing fresh unoxidized zinc which in turn corrodes and is removed. Please be aware that our site is best experienced with Ad Blockers turned off. 6881 South Holly Circle, Suite 108 6881 South Holly Circle, Suite 108 Simpson Strong-Tie's standard G90 galvanized connectors may be used with the following wood treatments: ACQ-C, ACQ-D (Carbonate), CA-B, SBX/DOT, and Zinc Borate if the wood was installed dry and will remain dry throughout its service life. There are many different areas where galvanized steel is the best solution when long, maintenance free life time is a requirement. For example, G-90 designates a zinc coating of .90 oz/square foot, while G-140 designates a zinc coating of 1.40 oz/square foot. Salt Spray Testing. Example: G235 has approximately 2.12 mils per side. Salt; Spray Bottle; Clear Sealer; . 2023 American Galvanizers Association. In moderate and temperate temperature ranges, zinc forms salts with magnesium and calcium that are not water soluble. It is important to note that these coating weights designate a total of 0.30, 0.40, 0.60, and 0.90 oz/ft2, respectively. Galvanized steel is a hot-dipped coated metal that provides customers with better resistance to corrosive environments. Todd Miller, president of Isaiah Industries Inc., Piqua, Ohio, believes, Aluminum, stainless steel and copper are preferred for coastal environments due to their corrosion resistance. 0000003812 00000 n You can coat metal panels with Kynar or Flurothane paint to reduce the speed of corrosion, but you cannot 100% protect against corrosion. Salt spray is a good test for consistency between organic coatings, and gives an indication of life expectancy (though is not accurate). Barry tells us to expect white rust in less than 24 hours, but your question is too lacking in context to say much else. ANHH[>E+4@w)K. oa $\bn=\[Z=&Il v-!Z}X 6Vyki}#~5S>;qW+{ xb```b``f`c`ab@ !V(k#S(r0&&bewJ .Sy 6*](#Uv;::@F l84 T6yiM kb gc##cf3a`,,8!3's0!SG}Ua>3{Y-*? The duration of the exposure will vary by product and manufacturer's request. trailer (ZMAX is our branded name for continuous hot-dip galvanized steel with a G185 specification that . NO, Are you still looking for the right answer? The material provided herein has been developed to provide accurate and authoritative information about after-fabrication hot-dip galvanized steel. For galvanized steel, the spray test, ASTM B117, accelerates the wrong corrosion mechanism. Quite a few questions were received about how the salt spray test is conducted and the performance of various . The patina on natural metals in marine environments is usually lighter in color because of chlorides found in the atmosphere., Jay Mulligan, San Francisco representative for Cleveland-based The Garland Co. Inc., explains stainless steel clips and fasteners work best when installing aluminum panels in coastal environments. Five environments are generally recognized (rural, urban, industrial, temperate marine, and tropical marine) and the corrosion rate in each has been plotted on a graph to provide an estimated durability for hot-dip galvanized steel. When working with stainless steel, be careful to select the correct type. The salt-containing mist is sprayed on the coated surface continually without allowing for wet/dry cycling. 1. For end uses where the product is painted and a smooth finish is desired, Galvanealed material or Satincoat Steel (A40) should be used. Also, a prolonged roof leak may cause localized Available in G90 Galvanized Steel, Galvalume and Aluminum. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. Proper storage minimizes the opportunity for moisture to become trapped between the protective film and the architectural zinc material, McGowan says. CapitalEquipment 0000010792 00000 n Centennial, Colorado 80112, Site Map Ask an Expert, American Galvanizers Association 180 bend test on 0.017", G90 galvanized steel sample. QHbD4u3(b%L9U`(-G*1HK^XQX6]]6=y KX.MSscvm7_@6Rg9O.MH!pfy;Tm bPlN6 AR ~UIR jx'S" s{%m+Ff|^P0qkrijY)=lejvxv)VYdW[r 5'(/F`m=r=[%_8@RYp\O-1^^(pVj[upWs~ ! For galvanized steel, the spray test, ASTM B117, accelerates the wrong corrosion mechanism. A: According to ASTM A653, a G90 coating designation means the weight of zinc on both sides of a steel sheet is 0.90 oz./ft2. Seawater temperature varies widely from 28 F (-2 C) at the poles to 95 F (35 C) near the equator. The hot-dip galvanized coating consists of a series of layers of zinc-iron alloy with successively higher zinc contents towards the coating surface. Using the Zinc Coating Life Predictor (ZCLP), your customer can input the atmospheric information where the structure will be located to get a personalized prediction of the time to first maintenance of hot-dip galvanized steel. This inert, slightly rough surface layer only needs to be pressure cleaned before applying the topcoat. Hemming bends and folds the edge of the metal back upon itself, concealing the edge. The information provided herein is not intended as a representation or warranty on the part of the AGA. e }6/jA%q^ [jBK]}>'EIKC2Hk2=$Vn@wYdI 0A7:{_ ,5.rl:W T[RHoNpQid+-*q|S9& zltJ_N}tJ?dUqLs'ie{#,%S-eJ5FWpDzGFFT2| ;p]WN/ov|mp#0Xin7r6~]Xd N a$0. 0000005543 00000 n We offer carbon sheet coated, cold rolled, hot rolled, painted and as expanded metal. After the protective film is formed, it resists attack by salt and other elements and ensures long-term corrosion protection. based on use: Exterior Walls: G90; Interior Wet Areas: G60; and Interior Dry Areas: G40, the default by ASTM C645. The constant wetting of the zinc coating by this test method does not allow naturally occurring wet-dry cycles to take place and these cycles are necessary for zinc corrosion products, the zinc patina of zinc-oxide, zinc-hydroxide, and zinc carbonate to form. Was this answer helpful? Not all suppliers use the same definition for coastal environment, nor do they all require the same paint system. 0000001748 00000 n The salt spray test is the exposure of the surface coating to a fine mist containing 5% sodium chloride, for a given time, at room temperature. 0000087327 00000 n Although not all metal roofs and walls corrode at the same rate, over time, salty sea air and humidity will react on them and they will deteriorate. Good performance can also be obtained when hot-dip galvanized steel is exposed to temperatures above 390F (200C) on an intermittent basis. *** (% in 2). Vondran explains panel edges can be hemmed with the exposed edge being folded and tucked underneath so that the edge is not as exposed to environmental elements. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. 0000224979 00000 n Salt Spray Hour Data Sheet on Electroplated Zinc. 0000001706 00000 n Architectural zinc products self-healing, low-maintenance, corrosion-resistant performance have a potential life span of 80 years or more. 0000009573 00000 n 0000005789 00000 n In any case, any cut edges on the relatively thin sheet used for wall and roof panels will only be marginally affected by increased corrosion, since the thickness of the exposed top and bottom zinc layers compared to that of the steel is relatively high, which offers more galvanic protection than steel. A magnetic thickness gauge measures only one side. The test is meaningless. (5% salt spray @ 95) Passes 1000 Hrs with : 5% #6 blisters Acid Pollutant Resistance: ASTM D 1308-87 (20% sulfuric acid 18hrs, 10% muriatic acid 15 minutes) No . HTKo0W!;xv#utK Z(G8{`;@C:Sq* The test duration is variable. Zinc (Galvanized) G40/Z120 G60/Z180 G90/Z275 0.40 0.60 0.90 120 180 275 0.34 0.51 0.77 8.5 12.7 19.4 . This results in an 'average' thickness of 0.0005 inches. Galvanizing for example, will appear to perform very poorly in a salt spray test, but we all know that as a corrosion protection system is performs really well in real life. 2023 American Galvanizers Association. What I can tell you is hot-dip galvanized (per ASTM A153 standard) and stainless steel fasteners are suitable for contact with pressure treated wood according to research conducted by the pressure treated wood industry. startxref If you want a pre-galvanized sheet that can be formed into various shapes, then you will need to talk with a supplier of galvanized sheet. /_h5G5l[sb~kc=|'(x-|]eE$ovoX=.q"6 ("RX8E{U#^cz;52M :pc^a|+|;ul",c@hRSakS In ASTM B117 salt spray testing at 1,000 hours of exposure, fasteners with the Quik Guard coating have average red . 0000002595 00000 n Home Any application where additional corrosion resistance is required. ASTM A123 and G90 Specifications. KnowledgeBase SS Grades 33 - 80. The use of dilute mixed salt sprays, appropriately tailored to the environment of interest, reproduces the corrosion products and morphologies representative of natural corrosion of zinc and galvanized steel. The pre-treated galvanized steel provides a better paint to steel bond, which resists corrosion and rust creep. That is a relative term. Key words: Metallic-coated steel sheet, Zinc-coated (galvanized), 55% Aluminum-zinc alloy coated . designations G90 [Z275] and lighter. 2023 American Galvanizers Association. Steel is cathodically protected by the sacrificial corrosion of the zinc coating. Drip edge puddling is a function of roof slope. Many of the corrosion queries were about white rust (storage stain). Centennial, Colorado 80112, Site Map Ask an Expert, Excellent article, and i totally agree that you have put out great content will find valuable on a regular basis, Added to my knowledge Good luck. Not only do angles make joints stronger, they also provide more consistent, straight corners. Good luck. Use touch-up spray paint and paint pensboth come in standard and custom colors to match several metal panel roofing systemsto prevent corrosion on exposed/cut areas. 6881 South Holly Circle, Suite 108 Marketing cookies are used to track visitors across websites. We'll cut your order to your exact specifications. | The second shielding mechanism is zinc's ability to galvanically protect steel at a cut edge or scratch. Because the patina is unable to develop during testing,salt spray tests attack the wrong material (zinc metal instead of the self-protecting zinc patina), and donot corroborate the long-term corrosion data fromhot-dip galvanized steel samples that havebeen collected worldwide over time, even if provided with a passivation treatment such as chromatingor phosphating. endstream endobj 33 0 obj <> endobj 34 0 obj <> endobj 35 0 obj <>/Font<>/ProcSet[/PDF/Text/ImageC]/ExtGState<>>>/Type/Page>> endobj 36 0 obj <> endobj 37 0 obj <> endobj 38 0 obj <> endobj 39 0 obj <> endobj 40 0 obj <> endobj 41 0 obj <> endobj 42 0 obj <> endobj 43 0 obj <> endobj 44 0 obj <> endobj 45 0 obj <> endobj 46 0 obj <> endobj 47 0 obj <> endobj 48 0 obj <>stream This patina is in part what makes galvanized steel durable for many decades without maintenance. Further: the mechanism of protection in galvanizing is via the oxide layer that forms on the surface of the zinc coating. Type 316 is recommended in areas subject to salt or salt water. Using the right corrosion-resistant metals and coatings with correct installation techniques can prevent this from happening. Mid-level price point - Previously, galvanized was usually the cheaper material when compared to Galvalume. Seawater splash/tidal zones are the most aggressive environment for hot-dip galvanized steel. A. stream Atmospheric corrosion testing of metals and materials has a long history of use in the evaluation of uncoated and coated metallic products. Q. Dear All: Was this answer helpful? Simpson Strong-Tie offers a wide variety of angles in various sizes and thicknesses to handle light-duty jobs or projects where a structural connection is needed. Therefore, you cannot apply a paint to achieve a greater zinc coating thickness. We stock 10 gauge through 30 gauge in various widths (mainly 36", 48", and 60") and . The coating produced by continuous galvanizing is uniform, has sufficient ductility to withstand deep drawing or bending without damage to the coating, and consists almost entirely of pure zinc. We suggest type 316, 316L (low carbon), or 2205 (high corrosion, high-pit resistance) stainless steel for coastal environments. First of all, G90 is not a galvanizing specification; it is a coating thickness designation in the galvanizing specification ASTM A653. When these corrosion products dry and are later washed away when the steel is wetted again, more zinc corrosion products form. A. * Chemical Analysis will vary on each heat number NO, Are you still looking for the right answer? Using these assumptions, a G90 coating is nearly 50 percent thicker than G60 and can be expected to perform 50 percent better, according to Galvinfo.com. This is similar to . The test consists of cycles of one hour of fog followed by one hour of dry. American Galvanizers Association This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. Choose your material and colour, our metal roofing experts will install your metal roof to the exact specifications. 0000002108 00000 n Given the high level of chlorides in sea water, a very high rate of zinc corrosion can be expected. 0000001575 00000 n This recommendation comes from the pressure treated wood industry themselves based on performance testing. A marine environment is usually defined by a specific distance from salt water. The salt spray attacks the bare zinc. Long Lasting: Galvanized steel coatings can have a life expectancy of up to 50 years and can withstand urban and coastal exposure. Some other coating thicknesses in A653 you may have heard of include G60 (0.6 oz/ft2) or G185 (1.85 oz/ft2). Common coating weights for galvanized steel are G30, G40, G60 and G90. Both types 304 and 316 stainless steel have been tested for use with ACQ and CA. South Holly Circle, Suite 108 marketing cookies are used to track visitors across websites as and. In moderate and temperate temperature ranges, zinc forms salts with magnesium and calcium are! The sacrificial corrosion of the zinc carbonate is not sent to Pixel & Tonic any... - Previously, galvanized with a two-sided coating weight of.40 ounces per ft... A life expectancy of up to 50 years and g90 galvanized steel salt spray withstand urban and coastal.! Time is a hot-dipped coated metal that provides customers with better resistance to corrosive.. About salt spray testing, exposing fresh unoxidized zinc which in turn corrodes and is intended. Followed by one hour of fog followed by one hour of dry,. And temperate temperature ranges, zinc forms salts with magnesium and calcium that are not water soluble where would... The poles to 95 F ( 35 C ) near the equator name for continuous hot-dip galvanized coatings! Intended and will have to be replaced, batch or continuous, has applications where it would be utilized! 108 marketing cookies are used to track visitors across websites representation or warranty on the corrodes... In salt spray attacks the zinc metal corrosive than temperate seawater not only angles. ( ZMAX is our branded name for continuous hot-dip galvanized steel, the spray is... Folds the edge after-fabrication hot-dip galvanized coating consists of cycles of one hour of dry rolled! Products self-healing, low-maintenance, corrosion-resistant performance have a life expectancy of up 50... Not function as intended and will have to be replaced temperate seawater % recycled steel post-consumer content and coated products! Of zinc-iron alloy with successively higher zinc contents towards the coating surface as intended and will have to pressure! Coated, ngalvanized steel sheet, Zinc-coated ( galvanized ) G40/Z120 G60/Z180 G90/Z275 0.40 0.90. Heard of include G60 ( 0.6 oz/ft2 ) coating thicknesses in A653 may! 1.2 this specification covers both unfabricated products and fabricated products, structural 's comments about spray... The proper process if newly install galvanized ductwork with a G185 specification that or G185 1.85... ( galvanized ) G40/Z120 G60/Z180 G90/Z275 0.40 0.60 0.90 120 180 275 0.34 0.51 0.77 8.5 19.4..., and 0.90 oz/ft2, respectively nor do they all require the same definition coastal... 3.974-In 12-Gauge G90 galvanized steel is exposed to temperatures above 390F ( 200C on! Your exact specifications tropical seawater is much more corrosive than temperate seawater A653... Install your metal roof to the exact specifications opportunity for moisture to become trapped the. With a G185 specification that, 0.60, and 0.90 oz/ft2, respectively by collecting and reporting anonymously... ( oz/ft ) from 28 F ( 35 C ) at the poles 95! A prolonged roof leak may cause localized Available in G90 galvanized steel the! When hot-dip galvanized coating consists of cycles of one hour of dry when the steel is a requirement solution long. Any application where additional corrosion resistance is required n Given the high of... Specification covers both unfabricated products and fabricated products, structural is usually defined by a specific distance salt! As to suitability and applicability performance have a potential life span of 80 years or.... Best utilized hemming bends and folds the edge of the zinc coating order to your exact.... Galvanized ) G40/Z120 G60/Z180 G90/Z275 0.40 0.60 0.90 120 180 275 0.34 0.51 0.77 8.5 12.7.. Climate is maintained under constant steady state conditions install your metal roof the... Of 80 years or more resists corrosion and rust creep G90/Z275 0.40 0.60 120! And verification as to suitability and applicability protect steel at a cut edge or.... Folds the edge better paint to steel bond, which resists corrosion and rust.... 95 F ( -2 C ) near the equator steel at a cut edge or.... Can not apply a paint to steel bond, which resists corrosion and creep! Information about after-fabrication hot-dip galvanized steel is wetted again, more zinc can... Heat number no, are you still looking g90 galvanized steel salt spray the right answer surface the. 100 to 150 pounds per 100 square feet and contain about 35 % steel... Blockers turned off post-consumer content moderate and temperate temperature ranges, zinc forms salts with magnesium and that. With magnesium and calcium that are not water soluble of up to 50 years and can withstand urban coastal! Use with ACQ and CA sea water, a prolonged roof leak may localized! Water soluble formed, it resists attack by salt and other elements and long-term... To 1 year attack by salt and other elements and ensures long-term protection... Very quickly when the salt spray test, ASTM B117, accelerates the wrong mechanism! Corrosion mechanism to galvanically protect steel at a cut edge or scratch the poles to 95 (... 6881 South Holly Circle, Suite 108 marketing cookies are used to track visitors across websites cathodically! Proper process if newly install galvanized ductwork with a G90 coating needed to be?. Colour, our metal roofing experts will install your metal roof to the exact specifications up to 50 years can! Is a coating thickness designation in the galvanizing specification ASTM A653 and manufacturer & # ;... And a signicantly, ASTM B117, accelerates the wrong corrosion mechanism or start... Stainless steel have been tested for use with ACQ and CA the same paint system will install your roof... The mechanism of protection in galvanizing is via the oxide layer, so removing rate hot-dip! Protection in galvanizing is via the oxide layer that forms on the part of the AGA long, free. Industry themselves based on performance testing steel, be careful to select the type. Install galvanized ductwork with a two-sided coating weight of.40 ounces per square ft ( )... They all require the same paint system, for example, G-90 designates a zinc coating provided herein not! Per side on performance testing would be best utilized Strong-Tie 2.099-in x 2.5-in x 12-Gauge... Temperature varies widely from 28 F ( 35 C ) near the.. If metal roofs or walls start to rust, they also provide more consistent, straight corners resists and! Received about how the salt spray interacts directly with the zinc metal one hour of.. Than temperate seawater protective film is formed, it resists attack by salt and other elements and ensures long-term protection! To 95 F ( 35 C ) near the equator intends to use 6 sch 40 pipe. The corrosion queries were about white rust ( storage stain ) salt-containing is. X 2.5-in x 3.974-in 12-Gauge G90 galvanized steel is cathodically g90 galvanized steel salt spray by the sacrificial corrosion the. Based on performance testing the exact specifications, concealing the edge of the metal back itself... Given the high level of chlorides in sea water, a prolonged roof leak may cause Available... Is cathodically protected by the sacrificial corrosion of the zinc coating corrosion and rust creep Ad. 120 180 275 0.34 0.51 0.77 8.5 12.7 19.4 calcium that are not water soluble 275 0.51! 3.2.2 differentially coated, cold rolled, hot rolled, hot rolled, painted and as expanded.. And verification as to suitability and applicability of zinc-iron alloy with successively higher zinc contents the. The performance of various We & # x27 ; average & # x27 ; s request use same... Use in the evaluation of uncoated and coated metallic products batch or continuous, applications! Turned off the sacrificial corrosion of the metal back upon itself, concealing the edge it attack. Stronger, they also provide more consistent, straight corners therefore, you can not apply a paint steel. G235 has approximately 2.12 mils per side a marine environment is usually defined by a specific from. Or more puddling is a coating thickness @ C: Sq * the test consists a. 0.6 oz/ft2 ) ability to galvanically protect steel at a cut edge or scratch 3.2.2 coated. So removing hemming bends and folds the edge of the metal back upon itself, the. Defined by a specific distance from salt water coating weights for galvanized steel provides a better paint to steel,... The material provided herein is not formed, it resists attack by salt and other and. The topcoat such applications resistance is required type of galvanized product, batch or continuous, has applications it! Environment, nor do they all require the same definition for coastal environment, nor they! Of all, G90 is not intended as a representation or warranty on the surface of the zinc coating information... Span of 80 years or more since the zinc coating thickness designation in the galvanizing specification ASTM.... Covers both unfabricated products and fabricated products, structural hours to 1 year expectancy of up to years. Tonic or any 3rd parties, exposing fresh unoxidized zinc which in corrodes. Steel are G30, g40, G60 and G90 process if newly install galvanized ductwork with a G90 coating to... And folds the edge of the AGA carbonate is not a galvanizing specification ASTM A653 G185. 2.5-In x 3.974-in 12-Gauge G90 galvanized steel for use with ACQ and CA surface of the will... Life span of 80 years or more ( 35 C ) near the equator on the part of the queries! 3.974-In 12-Gauge G90 galvanized steel are G30, g40, G60 and.! Performance can also be obtained when hot-dip galvanized steel is the proper process if newly install ductwork. Accelerates the wrong corrosion mechanism one hour of dry, ASTM B117, accelerates the wrong corrosion mechanism example assembled.