Re: Hot salts and aluminum BAD combination?
If the paint or sealant could be applied perfectly with no chance at all of any of the caustic salts getting to the receiver, that idea might work. But any paint applied that way could not be left in place. In other words, you couldn't just do a quick spray of the receiver and blue the steel barrel, you would have to make sure every part of the receiver was sealed off; if even a square millimeter was exposed, or the tiniest crevice remained open, the receiver would be ruined.
Then, because the receiver could not be used with all that paint on it, the paint/sealant would have to be removed from where it is not wanted, a time consuming process. And then you would still have to blue the aluminum in a way that would leave a working receiver. All in all, it is more efficient to simply remove the barrel, blue the barrel, and paint or anodize the alloy receiver.
FWIW, caustic soda does dissolve aluminum. A friend of mine was almost blinded because of that. He had been used to bluing M1911 magazines by washing them and throwing them in the tank without disasembly. One day he did that with a Browning High Power magazine, forgetting that the BHP magazine has an aluminum follower. He leaned over the tank just as the follower let go, with the spring throwing hot salts and the remains of the follower at his face. Fortunately, he was wearing goggles and his eyes were spared but he suffered burns of his face.
Last edited by Jim K; 08-30-2012 at 07:43 PM..