Type III Anodizing Finishes, I Need a Solution...

[50calshooter]

OK so if any of you have ever owned a Troy MRF Rail, or even the new MDT Tac 21 Chassis, you would have noticed the different type of finish it has. The finish is odd in that if you were to lightly scratch it or graze it with your finger nail it will leave a white mark, it seems almost kinda like a chalk residue. You can wipe it off easily, but for me (because I'm so anal about my guns) it gets really annoying. For comparison sake if you look at the ATRS billet lower it is more smooth and seems harder, if you scratch it lightly it wont leave a white mark. It just seems like there is some kind "powder" finish on the MDT, whereas the ATRS lower seems more like a true "dyed" metal.

So I'm confused they're both type III hard coat anodized, yet they have different textures on the surface...

Any ideas on why this is? ...and perhaps a remedy to make the TAC21 Chassis more like the ATRS Lower?

Thoughts?

 

[simonyzer]

Could your ''Chalk residue'' be sone nail grindings ? If you part is sandblasted before anodized it will have an abrasive finish. On the opposite, if the part is polished before anodizing, surface will be smooth..

 

[50calshooter]

Could your ''Chalk residue'' be sone nail grindings ?

No the slightest graze will leave the mark...

 

[alberta tactical rifle]

Different alloys take ano different than others.
6061 is fairly soft compared to 7075, the difference in ano is noticeable between the 2 alloys even when anoed in the same batch.
I have no clue what alloy your chassis is, but this may be 1 possibility.

 

[Claven2]

In all liklihood what you are seeing the the aluminum acting like and paper and abrading material off your nail. You see this when a piece of aluminum is heavily grit blasted prior to annodizing.