I thought I'd start another thread specifically about the browning process since the questions keep coming up. Besides, the other thread is getting kinda long.
I started the process yesterday morning, but made an embarrassing discovery when I pulled it out for the second application last night. I had completely missed one of the flats on the barrel! The other seven were getting a good coat of rust, but one of them was still silvery bright.
I treated it along with the others and let it go overnight. Looking at it this morning, it was nice to see that it had "caught up" with the other seven flats. I guess that points out how easy and versatile the LMF is.
It's worth pointing out that the start of the rusting is pretty slow and uneven, but not something to worry about. If you keep the faith and just keep on following directions, it will all even up. Somewhere along 24 or 36 hours into the process you'll have a nice uniform covering, but before that your pride and joy is going to look pretty scary. Just keep the faith and stick with it, and all should come out in the end.
From previous experience, I can tell you that if you get nervous and start carding the dark spots to even them up with the light spots, you can cause problems and slow the overall process.
Now I'm at the point of deciding how much is good enough. I'm going to rinse it this morning and do a very light carding (rubbing with wet denim), but probably give it another 24 hours before I do a heavier carding. Following that, I'll decide how much longer it needs to go.