Perma blue

[killzone]

Good day.

The search option on the mobile site is not always helpful. Anyway, I can't find any previous mention of Perma blue in a discussion on GS. Is it worthwhile ? Or is it money wasted that could have been contributed to gunblue or Cerakote ? Thank you.

[Dick]

Depends what you want to do with it. Perma-blue is a Birchwood Casey product. There are two versions, liquid and paste. Both are cold touch up blue, intended for scratches and minor holster wear. I used the liquid for bluing scope rings after lapping them. It is also a good marking blue.

Touch up blues are not as durable as proper hot blue, nor do they give a similar finish. That's why they are intended for concealing (almost) dings and scratches. The paste gives a better finish than the liquid. My buddy Richard Bowman and I blued a rifle barrel with it and got a fairly respectable result. But none of the touch up blues will give you a finish anything like as good as hot blue. You certainly can't blue a whole gun with it.

Hot bluing is not difficult. It is a perfectly practical DIY proposition for handguns and rifle actions. Simple tanks (stainless cooking pots) heat source (two ring cooker for R150), thermometer and a can of salts won't cost much more than a reblue by a gunsmith. Then you have the equipment and enough salt left for several more guns, and will have learned a skill into the bargain. Barelled actions are more expensive because the tanks and heat sources are bigger and more salts are needed.

I don't know anything about Cerakote.

[treeman]

Please elaborate on "salts" availability and what it is etc

[Dick]

Please elaborate on "salts" availability and what it is etc

First a bit of history to provide context. The first colouration of metal (other than paint) was browning. It was done by coating with saline solution which created a fine rust which, when brushed off, left a rust resistant brown colour. It took several applications. Some builders of replica flintlocks still do it for authenticity, but another Birchwood Casey product, "plumb brown" I think, does it more easily. Its how the Brown Bess musket got its name.

It was later discovered that acid solution does the same thing except that the colour is blue. One coat is very pale blue, but several coats gives a deep midnight blue. That's the origin of the term "bluing." That traditional process is called slow rust bluing. It is beautiful if done right but is impossibly slow, and takes several hours per coat and more than ten coats at one coat per day.

Modern factory/gunsmith hot blue is not blue at all, it is black. It is hot oxide blacking which did not originate in the arms industry, it is in fact much more used in other manufacturing. All the various knobs and levers on my lathe are blacked by that method. The arms industry adopted it at the time of WW1 or shortly after, because you can black hundreds of guns in a big tank in one hour compared with the tortuously slow rust method.

Hot oxide blacking salt is sodium hydroxide (caustic soda) plus two of the following : potassium nitrate, potassium nitrite, sodium nitrate, sodium nitrite. Of the two, one will be nitrate the other nitrite, never two nitrates or two nitrites. It is not a coating, it oxidises the surface of the metal a few microns deep. It is a rich black finish if done properly. The salt looks a bit like soap flakes. It is mixed with water in very exact proportions, brought to a rolling boil at a very exact temperature, and the parts immersed in it for 20 to 45 minutes. I found that nearer 45 worked best.

The only skill is the polishing of the gun before bluing, and the control of the mixture/temperature equation, which must be exact.

I think Genkem makes blacking salt, but I got mine from a company at Maitland, Cape Town. I'll look the name up.

[killzone]

Wow Dick ! You really are experienced in this field. My pistol needs a full re-blue. I was planning on taking it in to the GS after the hunting season but I'm embarrassed by it when others see it. So I thought of going the Perma blue route. You're making me excited by all your knowledge. It makes me want to do my own hot blue. Please keep giving advice and your recipe when hotblueing handguns. Thank you.

[Rick Pascoe]

Hi Dick,
Do you know if Nital S is still available and if so from whom? These are the salts I used up in Jo'burg 20 years ago and they always gave me superb results. My Mk IV series 70 needs a bit of a face lift and my old tanks and burners are still at Andy Fuller's place so I would not mind giving it a go again.
Thanks,
Rick.

[Dick]

Hi Dick,
Do you know if Nital S is still available and if so from whom? These are the salts I used up in Jo'burg 20 years ago and they always gave me superb results. My Mk IV series 70 needs a bit of a face lift and my old tanks and burners are still at Andy Fuller's place so I would not mind giving it a go again.
Thanks,
Rick.

No, Rick, I hadn't heard of Nital S. But that's not surprising - as you will see from my next post, my experience is very limited. The product I used was made by Mowatt, a UK based outfit I think. I got it from Metalquip at Maitland, Cape Town. In 5kg cans. Still have some, somewhere. I think Ludi Stark in Cape Town uses a Genkem product but I can't swear to it. As you know, its not difficult to mix if you can lay hands on the ingredients. But there's not much point if you can buy the ready made salt. I pass through Knysna twice a year on my way to and from Plett. Last time was June. Next time next June. I suppose you visit Cape Town often enough, and have contacts, that you don't me to do anything, but if you need anything dropped of that you are not in a hurry for, I'll be glad to oblige.

[Dick]

Wow Dick ! You really are experienced in this field.

Not really, Killzone. Rick Pascoe is your experienced man. A lifetime as far as I know, but he'd be able to confirm that. My gunsmithing career spanned no more than five years. I was a middle aged hobbyist turned pro. I had several years of machine shop at school so I had basic machining and hand tool metalworking skills. Firearms and workshop skills are natural bedfellows, and I had done simple work like scope fitting and action bedding for myself and friends. That included making simple parts like missing screws and the like. When a gunshop dealer asked me to do his gunsmithing it was a classic case of "in the deep end." I learned fast, because screwing up a customer's gun is not an option. For each type of gun I worked on for the first time, I read up all I could find then took them apart very carefully, making notes and diagrams at every stage. It was part time because, although my primary living was slow at the time I still had to do both. I reckon I worked on about 200 guns. That's not much compared with a professional gunsmith's lifetime of experience. But it was still a lot, because, except for some common guns like 1911s and 98s, I rarely saw a particular model more than once, so almost every job was a learning curve. Perhaps more significantly, I made parts for a third of the guns I worked on, including at least thirty firing pins. Most importantly, every gun left the shop properly done to a professional standard.

I blued maybe a dozen guns. That's not many, but bluing is one of those jobs that when you've done one you've done them all. I did have the advantage of being able to practice on two guns that no-one was going to buy until they had been refurbished. The real work is the polishing. I advise against mechanical polishing. Brownells Gunsmith Kinks Vol 1 has pages of description of polishing with wheels. The equipment is expensive and takes a lot of practice to use successfully. Smith & Wesson says it takes 15 years for a polisher to become fully proficient. In the sharpest possible contrast, a person with no experience can polish a gun to a good standard in a few hours with nothing more than a couple of small blocks of wood, a couple of pieces of round dowel, a small piece of thick leather, and half a dozen sheets of wet or dry paper. You might need a couple of small files if the gun has a few nicks and dents. Oddly, there is no adequate published work about hand polishing - the nearest is Dunlap's "Gunsmithing" but even that is sketchy. To digress a little, most gunsmithing books are an armchair read - they seem OK until you have to use them as a reference for actual work. I had a whole library of them and got very little I could use from them. The one exception that I can recommend is the Gunsmith Kinks series - there are four books in the set.

To illustrate that, I only ever found two references for stripping old blue. One was in Dunlap, I forget where the other was. You might not always want to strip the old blue, but it is often necessary. Much more important is the warning that is not present in ANY book or published work that I know of. It is that, if you strip the old blue, you have just sixty seconds after stripping to wash the parts and drop them into water displacing oil. If you don't they'll start rusting and you'll have a major rust removal job to do. That's because blue is stripped by 60 to 120 seconds immersion in pool acid. It leaves the metal chemically clean and subject to immediate corrosion.

I wrote a book about bluing. It is the most detailed set of instructions ever written. Regrettably I can't publish it because I completed the text before I realised I hadn't taken enough photos, and now I'm in no position to get them. I'm willing to send you the text provided you don't send to anyone else.

Just to illustrate what a gunsmith's life is like, and to establish my own bona fides, let me mention one or two examples. A Miroku o/u skeet gun had broken a firing pin. The firing pins are accessed via a pair of threaded plugs in the breach face. The plugs have two holes for spanner engagement, just like those crossbolts you see in the stocks of some rifles. I had to make a special spanner to remove those. Why remove both ? So I could measure the good firing pin. The firing pins are short and a particular shape which had to be exactly duplicated. The difficulty was that when the one end had been machined, that end couldn't be gripped in the chuck to machine the other end. So I had to make a little work holder. The firing pin tested perfectly when fitted to the gun, but two weeks later it came back after my new pin broke. So I took it Sanderson Steel's metallurgist who showed under the microscope that I had over-hardened it. Armed with proper heat treatment instructions I made another pin. It was still working perfectly when the gun was brought in for sale after several years of regular use.

CZ's bases and rings for its own rifles are very odd. The ring attaches to the base via a screw that protrudes up from the underside of the base. That makes it impossible to attach the bases to the rifle followed by attaching the rings to the bases. You have to fit the bases and rings to each other and to the scope and line them up with a straight edge before fitting the whole assembly to the rifle. It is unsatisfactory in the extreme. If a screw works loose there's no way of tightening it without taking the whole lot off the rifle. A screw had worked loose in the field thus ending the hunt. The owner agreed that, as there was nothing to lose, I could alter the bases and rings so that the method of installation was more conventional. It required some machining that was simple enough except that it needed a fixture to be made for holding the rings in the chuck, and a pair of threaded bushings to be soldered in the counterbores under each base. It was completely successful.

A not so routine alteration, and an interesting challenge, was the conversion of a Star Model B firing pin from non-inertial to inertial. It required a new firing pin to be made to a different length and design, a retraction spring and stiffer hammer spring to be fitted, and the whole lot to be balanced for reliable but safe function.

Every business has its lousy customers. One morning I arrived at the shop to find an air rifle stock on the bench. Split lengthwise from forend tip to through the pistol grip. It was the second such split, five or six millimetres from the first which had been repaired. It was a clean split so I glued it and clamped it by winding around it rubber strips cut from a truck inner tube. In addition, as this was the second split, I drilled and epoxied a steel pin down the middle of the pistol grip. Its a good method of reinforcing the pistol grips of heavy recoiling rifles. For good measure, the stock was quite rough so I sanded it and gave it a couple of coats of Tru-oil. All part of doing a good job for the customer, I thought. When he came to collect it I asked him for R75 (that was over ten years ago). He said, more or less "are you mad, at that price I'd rather have done it myself."

Aside from those occasional idiots it can be an interesting and challenging business, but not the fattest living considering the cost of setting up. Its the ideal business for a retired or semi retired guy turned pro, who needs to supplement his income rather than earn a full living, but the FCA put paid to that.

[killzone]

Thank you so much for the detailed reply Dick. In my eyes you're still an expert. There is no need to send me the instructions. The trouble and money spent will almost justify the R600 for a re-blue. Your knowledge is quite extensive. I enjoy reading posts where it is obvious an expert are writing them. Thank you once again for sharing your knowledge with us.