This is a somewhat abbreviated recount of a method I used in a attempt to create a finish reminiscent of a twist steel barrel. Here is a photo of a pair of Damascus Manton barrels I have - they are Damascus, not twist but they helped give me inspiration as I imagined what the colors may have been when new.
I experimented with different barrel stubs, and tried a dozen different things until I settled on something I thought I would like. Here are some of the tests that survived - not necessarily the pattern I wanted but looking for effects:
I ended up using a process that was a bit different than some I have read described. (Dave P. (Smart Dog) gave a great description how he achieved a faux twist finish) I first browned the barrels using a 10 percent solution of Birchwood Casey hot brown in water, heated the barrel and scrubbed the solution on with some denim scraps. I carded with a wire wheel between several coats and got this:
Then the barrels were painted with Dykem, which I found to be an excellent resist for ferric chloride for up to almost an hour. I tried various things I had in the shop, Dykem worked the best and was easy to work with, though smelly. Here is what the first round of Dykem stripe looked like - the barrel is browned, it doesn't show well in the photo. Anyone want a purple tiger-stripe barrel finish?
Then I placed the barrel in a cardboard box lined with plastic and sprayed ferric chloride on it with a spray bottle. I sprayed it again every few minutes and used an acid brush to recycle some of F.C solution that settled on the plastic back on the barrel.
Leaving the dykem in place, I blued the exposed steel with Brownell's Oxpho blue, then removed the dykem mask with acetone. I then took an acid brush that I cut a ragged edge on to make random fine lines, and painted another round of dykem in a smaller, more random pattern with a greater slant. The blue doesn't show well in the photo, but it was nice and dark:
Next came another round of ferric chloride, I went about 45 minutes each time.
The barrels were blued again, then the dykem removed with acetone.
Next I hit the barrels with a couple more coats of 10% hot brown solution, then a coat of dilute ferric chloride applied to hot steel. I sprayed the barrel down with ammonia based window cleaner, rinsed well then oiled. The next day, I de-oiled the breech end and blued it. The barrels did not have a Nock style breech, but just hooked plugs - so I had engraved a line on the top five flats to make the breeches look like they were full octagon plugs.
Last, after the barrels cured for a couple of days I coated them with some old Deftoil, a Danish oil - polyurethane finish. I had trouble getting good photos and good color with indoor lighting but here are some examples of the finished product:
I hope that description of the process is at least as clear as mud!
Thanks for looking,
Curtis
