Browning small parts

[rogerpjr]

I'm kind of curious about the process of browning small parts and staining the stock. From what I can tell, some old time builders left items such as barrel key underlays, entry pipes, nosecaps, etc. that were pinned in place on the stock when they stained the stock with aquafortis and the pieces browned in the process. Is this correct, and how would the browning color be controlled and neutralized? Wouldn't some of the acid seep under the pieces and not get neutralized? How would this affect brass or silver parts?

[Mark Elliott]

The only part I normally age or brown in place is the nose piece.   I am just careful about the carding to not mess up my stock which has normally been stained at that point.    I don't as a rule neutralize aging/browning and have no reason to think there has been a problem.   Usually my problem is keeping the rusting going, not getting it to stop.   I keep carding it until the rusting stops and apply wax.   I may wipe down the nose piece when I wipe down the stock with ammonia.   I don't use baking soda and a water rinse any more.    Actually,  I would be more concerned about stain getting under the nosepiece, but the ammonia should take care of that as well as the rusting agents.    I put the ammonia on liberally.