GTA
Airguns by Make and Model => Vintage Air Gun Gate => Topic started by: Yng@hrt on February 19, 2017, 10:59:23 AM
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Hello Timmy, can you tell me what metal you use for this scope mount? In addition, if the metal is aluminum can it be ordered w/o the bluing?
http://www.mac1airgunshop.com/product-p/iashba.htm (http://www.mac1airgunshop.com/product-p/iashba.htm)
Thanks
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Material used in the manufacturing is 6061 T6. The Finish is Black color anodized aluminum. It will take a .001" off of the surface to strip the part of color. Easy Off Oven Cleaner will accomplish the stripping. That removes all corrosion. Anodizing is electricity delivered surface corrosion with black dye in the mix.
Stripping an anodized part is A good way to loosen a part fit if you made it a few thousanths too big on the OD or a few thou to small a hole on the ID. Color anodizing is Type 2.
I haven't asked for raw mounts. Should not be a problem. I'll check.
TimmyMac1
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On checking raw mounts, great! If not I should be able to power buff the bluing.
Thanks Timmy!
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On checking raw mounts, great! If not I should be able to power buff the bluing.
Thanks Timmy!
Surface anodizing is 45+ Rockwell hardness. Aluminum Oxide can sand steel or sand anodizing off aluminum, but you will not buff anything off. You can buff once you use abrasives to remove the hardened surface layer. Since it is a square part you could sand finish it easy on a belt sander.
TimmyMac1
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I like anodized aluminum because the Threads are really sound. Rare to have a stripped fastener in an anodized part.
TimmyMac1
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This is way over my head so lets see if I understand you correctly; First use a product like Easy Off Oven Cleaner, then I can buff?
I use a Jewelers Rouge for buffing, of different grits.
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You can only sand the finish off to get to the soft metal underneath to polish (for best results). Stripping will leave threaded holes raw and oversize. Not good. Buffing will not remove the black finish. It is way TOO HARD! Once you sand off the hard surface you can polish the raw aluminum.
Why do you need Raw 6061? It will always self corrode/harden, be hard and flat looking (in the long run).
Tim
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Just wanted to try something different with my '65 Silver Streak. Had plans to keep all add-ons silver, including the scope. Maybe just a pipe dream.
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On checking raw mounts, great! If not I should be able to power buff the bluing.
Thanks Timmy!
Surface anodizing is 45+ Rockwell hardness. Aluminum Oxide can sand steel or sand anodizing off aluminum, but you will not buff anything off. You can buff once you use abrasives to remove the hardened surface layer. Since it is a square part you could sand finish it easy on a belt sander.
TimmyMac1
This^ One of the key ingredients in angle grinder discs is aluminum oxide. Gives you an idea how hard it is.
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Thanks for that information Sam. Places this bluing process into perspective & in terms I can understand. Timmy also raises critical points as to why chemical removal would be counterproductive in that of risking over-sizing fastener taps & weakening these high torque points. So without question raw mounts are out.
I am still a little bit confused though as to why this mount, if constructed of aluminum will corrode if the bluing is removed. Perhaps there is a difference between “Raw Aluminum” & aluminum I am accustom to seeing; i.e. aluminum cans etc. Are these treated with something that prevents corrosion?
...According to this article aluminum forms a layer of aluminum oxide which forms a protective layer against corrosion; http://news.stanford.edu/pr/00/aluminum511.html (http://news.stanford.edu/pr/00/aluminum511.html)
Maybe your chemists can shed some light on this? My oldest son is a chemist, I think I will discuss this with him next time we meet.
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Corrosion of aluminum is HARD. Surface corrodes and over time gets harder. Anodizing is electrically induced corrosion with color added. It is a hard protective layer like the surface would have on it's own after several years. When you polish you take the corrosion off so it can start fresh. Steel rusts. Aluminum hardens. That is what oxides do to the two materials. When we anodize we are protecting the part from corrosion because we have a protective layer of hard corrosion over the whole surface.
TimmyMac1
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OK, I think this dead horse (me) is finally getting the picture…when I think of corrosion I think of rust. Corrosion in terms of aluminum is oxide, the dull film that forms on the surface over time which actually protects the mineral against more severe forms of corrosion; in other words corrosion in terms of aluminum is more along the lines of electron microscopic levels.
If this is in fact true, I think it would be possible to slow the oxide reaction with the buffing compounds I use & form a different & more pleasing film of protection. Am I finally on the right page?
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Wax it?
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Yup
These are the steps I would take if I choose to remove the bluing;
- Aluminum oxide sand paper by hand. 1st 600 & then 2000. Flat surfaces only & not inside the dove-tail or obviously the screw taps.
- Cut 2000 sanding stage with fine mediums of polishing compound on power buffer fitted w/stitched pads.
- Run one last finish pass with Jewelers Rouge.
- Wax on power buffer
The last 4 stages are what I used to power buff my '65 Silver Streak. The one at the bottom;