Sand/Bead Blasting help...

[ar15barrels]

Or maybe I misunderstood? David, are your parts already anodized?

He never said they were anodized now.

[Broken Arms]

I've yet to run across receivers that are type II. But I'll believe you when you say you've seen that.

I was under the assumption that his receivers were already anodized when he said "I want to go for the raw look"

[ar15barrels]

I've yet to run across receivers that are type II. But I'll believe you when you say you've seen that.

I was under the assumption that his receivers were already anodized when he said "I want to go for the raw look"

Some of the 80% receivers are being done in type II just so they can be sold as "already anodized" to people that won't know the difference between type II or type III.
The anodizing is just for looks since it don't be protecting all the holes and slots that are being completed after the anodizing...

[David-K]

Really wasn't my intention to start an argument with my question. However, to clarify, my upper and lower receivers are currently anodized. When I mentioned "stripped" I was referring to them being "stripped of all parts" in order to be ready for sand blasting or whatever process will work best in order to achieve that raw aluminum look.

[couch]

Type II anodizing is 0.0002" thick.
Type III is 0.002" thick.
The pre-anodized 80% receivers are almost all type II anodizing.
If its type III anodizing, that means the holes will get etched open and then re-anodizing type III again will bring them back down to spec they started at.

If the receiver is type II now and he etched that off, the new type II plating will fix that too.

Type III penetrates the material by .001" and builds on the surface by .001" giving the overall thickness of .002". If you remove the Type III anodize out of a hole you are removing .004" off the diameter. Adding Type III to the same hole will only bring the diameter back up .002" total (since .002" total is penetrating the new hole...

Starting with Type III, removing then reanodizing you'r going to end up with holes that are .002" larger than before, unless they have figured out some way to suck the anodize out of the material without removing the material.

[badreligion]

Simple way to protect the holes. Leave the FCG pins in place during the blasting. No good reason to remove any material from this area unless your planning on using oversized pins.