Bass & Hays recommends using uncoated iron made in the U.S.A in accordance with LEED specifications, ASTM A48, A536 and AASHTO M306 to promote environmental awareness and not using chemical or petroleum based coatings.
Uncoated iron will cure naturally in time, there is no need to coat it with primers or paints containing harmful toxins that are unsafe for humans, animals and plant life. When an iron casting comes in fresh and new from the foundry, it appears grey or a dull metallic in color.
(similar to the ring on the first manhole picture in the gallery above) As the iron casting is exposed to oxygen and atmospheric conditions, it will begin to appear “rusty”. (usually a bright orange or yellow color) This is simply surface oxidation and is completely harmless. It contains nothing but iron oxide which is totally harmless to any form of life. It is water-soluble and will wash away. Rust should be left alone and not removed, it will eventually form a permanent patina which protects it from destructive corrosion. This a natural curing process which takes place over a long period of time is now generally preferred over any type of paints or coatings which may be very harmful to our environment.
The color of the rust can give us a clue about what type of atmospheric conditions the cast iron has been stored in… Yellow rust, or bright orange rust, is iron oxide-hydroxide FeO(OH)H2O (resulting from high moisture such as high humidity or rain) “Water soluble” iron oxide results in yellow or bright orange rust. This is the most commonly seen color after iron castings came in new from the foundry and have cured a few days in the warehouse or stock yard. Red Rust, or dark orange rust, is hydrated oxide Fe2O3•H2O (resulting from high oxygen/water exposure) Brown Rust, is oxide Fe2O3 (resulting from high oxygen and low moisture) Black Rust, iron (II)oxide – Fe3O4 (limited oxygen) Multiple forms of corrosion (different colors) can also be present at once most likely the result of rapidly changing atmospheric conditions. This is quite common especially in locations where weather changes dramatically and often. All of these forms of iron oxide are completely harmless to any kind of life.
Some municipalities do still require iron products to be coated. Bituminous or asphaltic solvent based paints were primarily used in the past. Paint was used to hide cracking and other defects and to attempt to prevent “rust”. We see this often in imported castings. This however does not prevent corrosion, and in some cases actually contributes to it by creating the destructive kinds of corrosion, which in time can cause castings to fail their service objectives and life. Coatings wear off in time anyway and defects will become obvious. The main problem with any coating is that as it wears off, residue containing harmful toxins flow into the storm drains, then into our creeks, streams, rivers and tributaries. This creates real water pollution. AASHTO M306 requires castings to be uncoated for this and for other reasons. If coatings are still a requirement for your municipality or governing district we can provide you with a safe alternative coating that is water soluble, contains no toxins and is completely harmless to plant, animal and human life, but still meets your service objective for using coated castings.
AASHTO M306. In 1989-2005, the American Association of State Highway and Transportation Officials (AASHTO) developed standard specifications for cast gray iron frames, grates, rings, covers for inlets, manholes and other iron casting structures. These requirements include coatings as well as load ratings, proof load testing, and other requirements. AASHTO M306 basically requires gray iron castings to be manufactured from iron conforming to ASTM A48, Class 35B or better. Ductile iron castings shall conform to ASTM A536 or better. Iron material used in these products shall have a minimum post consumer recycled material content of 75%.
Gray Iron- conforming to ASTM A48, Class 35B, as noted in section 7.1.1 and 7.1.3 of AASHTO M306. Class 35B exhibits the best corrosion and wear resistance properties as well as the desirable quality of high compressive strength. Therefore it makes a good load bearing street hardware. 35,000 psi minimum tensile strength iron is furnished.
Ductile Iron- conforming to ASTM A536. Ideal material for construction castings when standard gray iron castings do not have the load bearing capabilities. Ductile Iron has greater strength characteristics than structural carbon steel without the corrosion characteristics of steel. It is usually used in areas subjected to loads when greater than H20 loadings are required. It also has excellent compressive strength and is lighter than gray iron. It is usually recommended as a cost effective approach to mate ductile iron lids or grates with gray iron frames.
Steel Grates- Material shall be hot rolled steel confirming to ASTM A36. Galvanizing is recommended for all steel frame, grates & covers, conforming to ASTM 123. Steel grates can be compatible with cast iron frames.
Bass & Hays® American made castings meet or exceed LEED requirements for recycled content of 85% made up of approximately 20% post-consumer and 80% post-industrial materials. By adhering to the LEED requirements we ensure that we meet or exceed the recycled content requirements of AASHTO M306.
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