I have browned my last ? 20+ rifles in the bathroom. Shut off the vent & cover it.
Put a electric heater in there til it is about 85 deg.
Run the shower til the water on the mirror drips.
Put an old shower curtain flat on the lavatory.
Block the barrel up on each end with a piece of 2x2 about 6" long.
For Browning, sand barrel no finer than 220. (I glass bead my barrels & trim) Wet a cotton ball with the solution & just swipe it down the barrel on time, next flat one time, etc. Let it sit for 3 hrs. Card it with a Dixcel Wheel (Brownells) at about 1100 RPM. Apply solution again, repeat procedure.
DO NOT go over 3 hrs between carding or big flakes of rust will come off & then it is mottled looking.
DO NOT apply a second coat if you miss a spot or rub the solution on again, til After the 3 hrs. You will get it on the next round & it takes 6-7 applications to completely brown a barrel, using this method.
Takes me about 21 hrs to brown a barrel & the furniture. Yes I get up in the middle of the night or morning several times, but it is done.
Neutralize well with baking soda in boiling water. Wait 3 days to Insure it has stopped rusting. If it has not, neutralize it again. Grease the bottom of the barrel with RIG & put it in the stock.
Keith Lisle
PS: I use Latex gloves & change them every time I handle the barrel. Also take alcohol wipes & wipe off the doorknobs, as women love hand lotion & that has oil in it. This oil can cause uneven browning if it gets on your hands, then on the barrel.