What do you use to remove the water based polyurethane from the bores after the job is done Ken? I've been using shellac which is fairly easily removable with denatured alcohol. I've also used rubber plugs with pieces of brake line tubing bent upwards at 90 degrees to vent any pressure above the boiling tank surface. I like Damascus's idea of using a long piece of all-thread to secure the stoppers, but my boiling tank would not be long enough for a few inches of all-thread sticking out of the ends of 30" tubes. Maybe a piece of all-thread just a bit longer than the barrels with a couple pieces of flat stock for hooks/handles, held on by the same nuts that secure the plugs...
Has anyone tried using steam rather than boiling tanks? I saw one set-up on the internet that used a vertical 3" PVC pipe that was glued into a toilet bowl flange, which was screwed onto the perforated lid of a pot. Barrels were suspended vertically in the upright PVC pipe once there was a good head of steam. Said advantages were much shorter rust conversion times due to not having to boil a much larger tank of water. No need for a pipe or multiple burners. Less fuel consumption, and the guy claimed that most of the original gun manufacturers used steam.
I agree that this is a great thread, and there are always new techniques to learn from the experiences of others.
Keith,
I use a long steel rod with the end shaped to hold piece of a green scrubby pad. I use that in my electric drill. The pad is cut so that when the two sides are folded in (like a spiral) they fit snug while the rod is spinning. I soak the pad in acetone, and use a hull as a bushing for the chamber. Besides removing the poly it does a real good job of polishing the barrels. I work from chamber to muzzle, and make sure the pad never comes completely out of the muzzle. Someone on this board mentioned using a green pad this way, that's where I got the idea.
What I've read about steam is that you've also got to be able to use dry heat as a part of the process, as constant steam will cause droplets that cause spotting. The Parker Process mentions "wet" and "dry" heat. My drying cabinet (old metal wardrobe type cabinet) uses a large crock-pot full of hot water in the bottom, set on high. I've three rows of rods mounted at the top, the barrels hang vertically on rod hangers. There's enough room for a dozen barrels. It's warm and muggy like an Iowa summer in there. Four-hour rust cycles are no problem.
My boiling tank is made from a cylinder, I use it vertically on a high-output natural gas wok burner. My other tanks are mostly made from 3 1/2" PVC, used vertically as well. They're for Ferric Chloride, neutralization (Baking Soda), Logwood, (I pour boiling logwood in, then soak the barrels). For the Ferrous Sulphate soak I use an open tray, made from a section of plastic rain gutter..
Here's a question of my own. It's about ribs with minor leaks. Whenever I see evidence of a rib leak I use the "two hole" method so I can flush and blow out the liquids with compressed air. After completion, do you put anything into the rib void? I've read that some use shellac. I've got a cutting edge rust inhibitor, I'm considering blowing that into the rib and then following up with shellac to prevent corrosion.
