Home Forums Hunting & Shooting Gunsmithing Rust Blueing Question

The cold rust bluing solutions will cause rust only on the surface applied to. I plug the bore just because I can. Some guys "paint" the bore and other areas that are not to be blued with varnish or clear laquer and remove it after the last carding.

Kind of a guess, Craister, but between 600-700? I've got a variable that goes as low as 500, and I pick it up a bit from there.

I run my carding wheel on my drill press. I pretty much keep it on low speed.

I use fitted dowels - but only to have some sort of handle. I remove the dowels during the boil-up. After drying the parts, inside and out, I fit the dowels and do the carding. The dowel acts as a handle during the application of the new rusting solution. I haven't had any problems with rust in the bores.

Hello Guys - Great thread.

I'm wondering about the acid based solutions and the "nails" that are specified when formulating these. I assume we are talking here of "iron" nails - is this so ?? If one didn't have any known "iron" nails to hand what would be the best subsitute - ordinary cast iron pieces ?? Wrought iron pieces ?? steel nails ??

Cheers - Foster

Howe's Book, The Modern Gunsmith lists 20 browning/bluing solutions. Most of them contain ferric chloride and corrosive sublimate, along with other ingredients. Formula #6 consists of a combination of nitric and hydrochloric acids, to which are added steel chips or iron nails. After the iron completely dissolves, distilled water is added and the solution is allowed to stand (in a blue bottle) for 2 days (!).

I think the iron nails basically form Ferric Chloride when dissolved in hydrochloric acid (HCl). The corrosive sublimate is Mercury(IV)Chloride and is VERY nasty stuff. I refuse to have anything to do with it. I always use a solution that doesn't contain it.

Iron, steel are pretty much ok for making bluing solution. You must avoid galvanized nails, as the zinc plating will wreak havoc with your process.