The easiest way to do a boil out for rust blue, without the tanks or distilled water.
First off, if you want a smooth finish, most let the barrel rust too much before boil out. I just get the lightest discoloration, than steam. Usually 5-6 cycles to do it.
Get a pvc tube, and cut to length needed.
Get a pot to boil water in. I had an old cast iron pot, about 8" in diameter.
You should find a flange that the PVC will fit into. This was the most expensive part of the project, around $25 at a plumbing supply shop. I used some 4" pvc since that is what I had laying around. Smaller diameter would be easier to find a flange for. The flange makes it easier to balance the pvc lid on the pot. Flange too big for your pot? Get a piece of wood or metal, cut a hole to allow steam through, and screw the flange to this.
Once this is done, bring the pot of water with the cover on, to a boil. I did this outside, with a propane burner. Once you have things boiling, set the pvc with the barrel hanging inside over your drilled steam vents. I used a piece of scrap metal, with a hole drilled through, and a wire as a hanger.
Leave your top metal have a bit of venting, to allow the steam to easily circulate in the tube.
Steam for 20 minutes, and you are done.
I simply dropped my smaller parts in the boiling water. You could also make some other smaller pvc container to steam separately if you like.
The steaming would only really need to be for around ten minutes. The extra time I used was for the parts that were actually being boiled, as the temperature was below the steam temperature.
I believe steaming would also eliminate any concern about not having distilled water, as I saw no spots or other problems from steaming, and I have hard water here.
I also use the soft stainless steel wheels from Brownell's for rub out, work great.
