Ref the blacking of dissimilar steels showing up poorly in angled / diffused light or fading with flux migration.
In my youth (before the Civil War) I was a process chemist in a very large metal finishing outfit. We had a wrinkle for handling welded and brazed assemblies that were to be blacked (hot blacking in this case, the nitrate / nitrite / caustic variety).
The entire piece was iron plated before any other processing; from memory to about .0005". Mostly these were for military applications, no one else would bear the costs that the MOD would. The MOD inspectors were pretty pernickity and again from memory we never had one slung back.
I see no reason why it shouldn't work with sleeved barrels if someone really wanted to push the boat out. Simple enough to do, and not expensive if you already have the basic electroplating hardware to hand. You might have to piddle about a bit to find an optimum deposit thickness, but that's all.
Eug
Last edited by eugene molloy; 03/17/12 03:54 AM.
