Larry Chesterfield
What is the Correct Anodizing Specification?
My company fabricates aluminum and steel pedestrian bridge railing among other bridge parts. We recently got an aluminum railing job that called for “Type I” anodizing per MIL-A-8625. There was no anodic coating thickness called out. We are not anodizers and we are at a loss as to how to write up a meaningful anodizing specification for this railing.
Read MoreTeflon Impregnation and Wear
Does Teflon-impregnated aluminum offer a higher resistance to wear or corrosion?
Read MoreThe Problem of Sealing Smut
Is there an anodizing cleanliness standard that is reasonable for our suppliers to meet? Is there an ISO, ASTM, IPC, Nadac or any other standard?
Read MoreDichromate Sealing and Fatigue Life
We are looking for some references that show that dichromate sealing restores the loss in fatigue life caused by hard anodizing aluminum alloys.
Read MoreMore on Anodizing Die-Cast Aluminum Alloys
The anodized parts are a dark gray color. In addition, we perform a salt spray test and the parts show corrosion pitting over more than 10% of the test panel after only 72 hr. Do you know if this is normal?
Read MoreStripping Hard Anodic Coatings
Our company has an anodizing vendor that recently had some problems with our hardcoat anodized (Type III) parts. The problem was leakage around the masking, resulting in poor quality parts. The anodizer claims they can chemically strip the hardcoat and re-anodize the parts. Is it possible to strip hardcoat anodized coatings?
Read MoreHardness of Hardcoat Anodize
Question: What would be the hardness of the Alcoa Alumilite 226 hardcoat finish? The substrate is 6061 alloy aluminum tubing. G.S.
Read MoreMore on Type I vs. Type II Anodizing
In a question I addressed back in May, C.S. asked about rinsing Type I (chromic acid anodizing) coatings vs.
Read MoreGlue Adherence to Black Anodize
Question We’re having a problem with glue not adhering to anodized parts made from extruded 6063-T6 aluminum and finished with heavy etch and black anodize per MIL-A-8625, Type II, Class 1. The problem parts come in batches, something like a 25–50% fallout rate, when we normally have about 0.5–1% fallout.
Read MoreProblems with Black-Dyed Parts
Recently, we’ve had rejected parts because the black dye is coming off when the parts are wiped down with DI water.
Read MoreCALCULATING ANODIZING RATE FOR TYPE II AND TYPE III COATINGS
Question: We’re new at anodizing and we would like you to explain how to calculate the time it takes to get a given coating thickness when you have more or less “standard” anodizing conditions.
Read MoreTYPE I VERSUS TYPE II ANODIZING
Question: I operate a small sulfuric acid anodizing line and have a question about chromic acid (Type I) anodizing.
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