Roger that! Been working around aluminum all of my adult life, I know its characteristics all too well.
Identify this GC model???
- Thread starter davelpl
- Start date
The anodizing is so hard there is no way it just wears off. I had a rough go getting through it with a palm sander and 120 grit.
In a commercial setting for decades that coating stands zero chance of remaining fully intact. All it takes is a small area to be exposed. Your table had been storage for years from what I remember?
DeeDeeCues
Well-known member
Cool story, but aluminum anodize absolutely wears off. The wear is accelerated with exposure to UV, acids (which are present in many cleaners and in hand oils).
The anodize on my trim came off relatively easy by hand sanding with 400grit, but I used the correct type of abrasive, and lubricant. When you use
The anodize does not have to wear off completely to transfer a lot of gray to objects. Aluminum is an extremely fast oxidizing metal. The natural oxide is what is transferring to clothes.
DeeDeeCues
Well-known member
Considering that the trim is almost definitely Type II anodize at 1/10,000-5/10,000" thick, you are correct. The anodize on the trim is not, 'Hard' anodize, which means Type III. You know this, obviously.
Working in industry designing a ton of aluminum parts for huge scale CNC automation machines, I rarely specified Type III anodize. Type III was pretty much reserved for parts that were moving on other parts, dispensing liquids (and not consumables), and other critical applications. For general appearance and normal corrosion resistance, Type II is sufficient.
No. I pulled it from a bowling alley bar. I'm unsure how much use it got, but based on the rails and slate backer, it had only been recovered once, maybe twice.
I'm all about cool stories. I'm just reporting my personal experience. Side note: I've got some bare aluminum bike parts. If I rub them with a clean cloth, no transfer. If I add a little Autosol polish, black transfer which I assume is the oxidation.
We have a lot of anodized (hard coated) parts on our racecars, the hard coat wears off everywhere there is friction. My kids raced karts when they were younger, the rear sprockets are hard coated because without it a sprocket could wear beyond use in just weeks. Anodizing extends the life of aluminum that wears but does not eliminate the wear.
The first time I polished shiny aluminum wheels with Mothers polish I was dumbfounded over where all the black stuff was coming from. Aluminum is weird stuff that way.
I always say "I don't know what I don't know". The above definitely falls into that category, thanks for the info, now I have some some more stuff to learn up on.
DeeDeeCues
Well-known member
Here is an assembly on a base of 7075 aluminum I machined this weekend. The paper in the lower right corner shows a spot of gray where I swiped a 2" path with my thumb and light pressure. I cleaned it with 99% alcohol a few minutes before the photo.
DeeDeeCues
Well-known member
100%. A lifelong journey of learning. Be well.