De-rusting and etching Damascus gun barrel

[RDGAC]

Howdy lads and lasses! Been a little quiet here of late, not too much to keep me occupied on the ethnographic weapons front; my jezail's barrel's in the works, and another of the monsters on the way, but that apart, no developments. Except...

Having taken a look at Spunjer's thread on the Silver Surfer (I do like the name, by the by ), I've begun to wonder if it might be worth trying to sort out this Damascus barrel we've got on the Museum jezail. In considering this, I have obviously to observe two conditions: that I do it right, and do the right thing. To address those in reverse order: whilst I'm aware that the consensus, on the whole, is that museums (and indeed collectors) should seek to preserve the objects in their care in their current condition, rather than seek to restore them, I'm increasingly of the opinion that this is a special case.

It seems a tragedy to let the world see one more rust-encrusted gun barrel, when a quick strip-down, taking no more than ten minutes, will reveal that that barrel was once, and might yet be again, a thing of exquisite beauty. Don't we have enough aged, unrestored muskets kicking around? Or am I just getting consumed with my (entirely transparent) desire to see the whole barrel regain the appearance that only its protected parts now hold, and have before me a genuine example of the wonders of Indo-Persian craftsmanship, whose qualities I can at last show to our beloved punters?

Morally, I can't help feeling that the best thing to do would be to work towards the eventual goal of restoring the barrel as best I can. But practically - even if the argument is sound, in other words - we still have the problem of doing it right; this is point one, of course. How does one go about this? What are the risks? This particular barrel is, as those of you who saw my first thread here will have seen, badly rusted. Mottled with it, in fact. So the question becomes, how do I remove the rust and then, moreover, how do I etch the barrel? Is there a high risk of damaging the pattern in that process?* The practical question that vexes me the most is that of avoiding damaging the remaining pattern on the barrel's surfaces; if, in the course of rust removal (chemical, preferably, to avoid mechanically damaging the pattern), I remove the patterning I'm trying to bring out, it's a bit of an own-goal.

So, yes. Arguments and help, go!

* Do beavers mate for life? Is there any means of knowing if there is a god? Has anyone seen that tin opener I lost some while ago? Etc...

[ward]

any lose or huge surface rust take off. you can do somehing as simple as take sand in your hand and run it across the barrell a few times. take a towel with some ammonia across it and then etch it. are you going to have some pitting it yes you will. it still will look better than what you have and you will not lose pattern at this point. you start having concernes about losing pattern when you take off layers

[kai]

In quite a few cases, the insistance to change nothing seems hardly more than an excuse to me, even in a museum setting. Under perfect storage conditions even red rust may be stable and not active. However, history has proven again and again that conditions are unlikely to stay perfect for centuries. Moreover, these conditions are more than likely to damage any wood or horn which may be attached to such a piece of iron - so, you'll have to decide on a compromise anyway.

Under usual collector's conditions (and many museums are not better equipped or cared for if at all), I regard active rust as an serious infection which needs to be treated (like any museum worth its name would kill off any bugs by fumigation/gas/heat treatment).

I agree with Ward that to preserve the topographic patterning one should avoid anything that may cause abrasion of the steel like sandpaper and, especially, power tools! I'd also be hesitant with even fine sand since it can scratch the steel. Why not only use very fine steel wool, oil and lots of elbow grease to stay on the safe side of things? Top it off with a quick etch and I'm sure you won't regret the restoration!

Regards,
Kai

[RDGAC]

Thank you both for your input. I should have been more specific, however; this is old, very inactive rust (brown-black, in fact) which is pretty hard to get rid of. The active stuff I've already dealt with; it's this hideously ugly, but nonetheless fairly innocuous, black patchwork that I'd like to combat if I can. The problem is, of course, that it's very firmly bonded to the steel. Mechanical means seem difficult to pursue as a result, and chemical treatments have the potential to go very badly awry, hence my concern over whether to proceed. I can try applying de-corroding chemical treatment, for instance, but I do worry about it destroying the pattern. Alternatively, I can try using a brass pick and oil and a lot of patience, which should leave a surface that can be etched - in about six months.

[RDGAC]

A quick update. I've just come away from a small experimental session with a fine steel pick, lubricated with a coating of common 3-in-one oil. The result? The rust is, it turns out, much softer than the steel (not surprisingly), meaning it can be picked out - it will take an awfully long time to do the entire barrel, but it can be done. The picture illustrates the difference; the circled area has clearly enjoyed a sort of topographical reversal, with the rust (formerly proud of the barrel's surface) now diminished sufficiently to be at least level with the walls of the pits it has made in the metal.

The second thing that I've determined is that this will take, almost literally, forever. But, if I'm careful, I should be able to avoid damaging sound metal. I think this might be the (extremely slow, painfully laborious) way forward, coupled perhaps with gentle use of 0000 steel wool and yet more lubrication. (Yes, I take the blame for rising fuel prices.)

[ward]

the part you are missing is that etching is a acid and will eat rust just as well as iron. do not soak the piece in any oil yet. It will just screw up the etch. The only reason you completly sand a barrell down is so when you do the etch you get a complete mirror finish on it. the longest I have ever etched a piece was 17 days for a slow etch. A quick etch can be done in a few minutes

[RDGAC]

Ward, I appreciate that acid should chomp through rust just as it will cause the appearance of the watered pattern by removing some of the softer iron. What I still worry about is whether the effect will be what I desire. To give you an idea of why, I discussed in an earlier thread the effect of Renaissance Metal De-Corroder on the watered steel of this barrel and various other objects. The results were varied. Rust went, but so did lustre, and I find myself unsure of whether repeating the process - bearing in mind that this stuff is, as far as I can tell, an aqueaous solution of hydro-oxycarboxylic acid - is a good idea.

Some pics, herewith, of the areas of this barrel I treated with this acidic solution. The pattern remains visible, one way or another, but in the tang area (which was subjected to the longest treatment) the shine has vanished from the steel. A consequence which, along with the low visibility of the pattern, I wish to avoid.

[RDGAC]

As an aside, I apologise for being so over-cautious, and for asking questions over and over again. The thing is that I feel very much responsible for this gun, not only in a personal, but in a professional sense. I don't think I'd ever really forgive my own ill-judgement were I to ruin, by carelessness or omission of action, a wonderful artefact that has stood the test of, in all likelihood, centuries. So thanks for being so forbearing. If I can get my concerns cleared up, I think this barrel will look truly beautiful once restored fully.

[ward]

ok use the bottom of the barrell it will never be exposed after reasembly. just mask off around it. you can test your various acid test on it. then no harm no foul

[RDGAC]

Right. Ordinary Duct tape will do for masking off the un-etched sections of the barrel, I take it? And as for etches, what would you recommend? I know that a quick etch with vinegar helped to bring the pattern out slightly. But presumably something a little stronger is desired for a full etch of the metal.

[rickystl]

Hello. Interesting Thread. A process recently introduced to me by a black powder gunsmith is Glass Bead Blasting (NOT sandblasting). This process has the ability to remove rust without removing the original patina of the metal. I've experienced this first hand. If you go to the Web-Site (link removed by moderator) and look under Services you will see an original Spanish Miquelet lock I own. The before and after photos are amazing, as you'll see. I don't know the effect it would have on Damascus, but it might be worth asking Earl Kathan. He is very knowledgeable in this area. Might save you a lot of time and experamintation? Rick.

[Rick]

Bead blasting could be a viable alternative .
This service is widely available .
There are all kinds of blasting media that would not damage steel; retaining patina might be a problem .

[RDGAC]

I'm a bit wary of any blasting process, in no small part because I have in my possession a bayonet (French Chassepot model, I think) which, unfortunately, was glass blasted in order to remove rust. Patina's gone, but more critically, so have some small details on the blade itself (stamped and engraved numbers and letters) which would have helped ID it. With that in mind, I'm not sure about using it on this barrel. I think first thing to do is try my hand at a gentle experimental etch with a mild acid, on an area which remains out of sight but which has remaining pattern and corrosion. That'll enable some assessment of the results. Any thoughts?

[Rick]

Yeah, I was thinking Walnut shells .

[ward]

Ferricc chloride is a standard ferric sulphate, muratic,photoghraphic fixer,etc. If it were me I would try a small amount every inch or so it will be easy to compare the results. I use bee's wax to mask off items. make sure you apply your acides or salts with a cheap paint brush. Also make sure you nutralize it after. some just use soap and water afterwards. you can also use baking soda if paranoid. I would not glass bead anything unless you want to lose crisp edges and detail work.
ward

[RDGAC]

Just did a quick experimental etch with citric acid; pretty mild stuff, but the FeCl3 is on order now (in pellet form; didn't fancy the prospect of having to hump a 5-litre drum of liquid acid about). The result's been mixed. It's definitely resulted in a slight etch; problem is that, just as with the de-corroder, it's also dulled the surface. I'm not sure whether that's something that's inherent to the etching process, or if I'm just making a mess of it.

Hopefully, even a dulled surface can gently be polished back to life. Anyway, I'm going to proceed with a test etch using FeCl3 once I've got it and made it up to the appropriate strength. Should be good; fingers crossed!

[Ibrahiim al Balooshi]

Originally Posted by RDGAC

Howdy lads and lasses! Been a little quiet here of late, not too much to keep me occupied on the ethnographic weapons front; my jezail's barrel's in the works, and another of the monsters on the way, but that apart, no developments. Except...

Having taken a look at Spunjer's thread on the Silver Surfer (I do like the name, by the by ), I've begun to wonder if it might be worth trying to sort out this Damascus barrel we've got on the Museum jezail. In considering this, I have obviously to observe two conditions: that I do it right, and do the right thing. To address those in reverse order: whilst I'm aware that the consensus, on the whole, is that museums (and indeed collectors) should seek to preserve the objects in their care in their current condition, rather than seek to restore them, I'm increasingly of the opinion that this is a special case.

It seems a tragedy to let the world see one more rust-encrusted gun barrel, when a quick strip-down, taking no more than ten minutes, will reveal that that barrel was once, and might yet be again, a thing of exquisite beauty. Don't we have enough aged, unrestored muskets kicking around? Or am I just getting consumed with my (entirely transparent) desire to see the whole barrel regain the appearance that only its protected parts now hold, and have before me a genuine example of the wonders of Indo-Persian craftsmanship, whose qualities I can at last show to our beloved punters?

Morally, I can't help feeling that the best thing to do would be to work towards the eventual goal of restoring the barrel as best I can. But practically - even if the argument is sound, in other words - we still have the problem of doing it right; this is point one, of course. How does one go about this? What are the risks? This particular barrel is, as those of you who saw my first thread here will have seen, badly rusted. Mottled with it, in fact. So the question becomes, how do I remove the rust and then, moreover, how do I etch the barrel? Is there a high risk of damaging the pattern in that process?* The practical question that vexes me the most is that of avoiding damaging the remaining pattern on the barrel's surfaces; if, in the course of rust removal (chemical, preferably, to avoid mechanically damaging the pattern), I remove the patterning I'm trying to bring out, it's a bit of an own-goal.

So, yes. Arguments and help, go!

* Do beavers mate for life? Is there any means of knowing if there is a god? Has anyone seen that tin opener I lost some while ago? Etc...

Salaams ~ This entire subject is, I believe, very important to the whole forum since rust is encountered on most weapons and everyone has their own formulas for cleaning; some better than otheres perhaps. I have had some success with lemon acid and the occasional disaster with car battery acid in over pickling the object. I believe an article on cleaning techniques could be the answer and suggest moderator guidance on a forum produced guide. Perhaps this could take the form of an announcement across the forum... I for one would like some guide on what are the best ways to de rust an item .
Much liked this article by the way !

[Lee]

Received from Ken:

Lynton McKinsey used a saturated solution of Boric Acid to remove rust from important pieces. Soak and card with a brass brush daily. It is a long process, but won't attack the sound steel.

[Ibrahiim al Balooshi]

Originally Posted by Lee

Received from Ken:

Salaams,
Moderator Staff,
I believe there are scores of different techniques out there. Would it be possible to open a forum A TO Z to which members could add their cleaning ideas as the forum roles forward which could then be an easily accessible resource ~ and ongoing.

Ibrahim Al Balooshi.

[imas560]

Hello all,
RDGAC did you find a rust removal and etching process that produced the results you were happy with and would use again?
Did you try the Ferric Chloride?
thanks

[estcrh]

Here is a rust removal process used by Ian Bottomley (Curator Emeritus of Oriental Collections at the Royal Armouries Museum based in Leeds). This was originally posted on the Samurai Armour Forum, Ian has had a lot of experience stabilizing and restoring Japanese armor, his process my be helpful to some forum members.

All, I thought I would just publish details of a russet mask undergoing cleaning. The mask in question was very badly spotted with secondary rusting, some of which had developed into quite bad active rust encrustations. I used my usual mixture of boiled linseed oil thinned with white spirit in a ratio of approximately 50 / 50 - it isn't critical. The mixture was applied with a paint brush over a small area and allowed to soak in for a few minutes before rubbing the area with a chisel shaped piece of stag antler. You can see that it is working because the secondary rust comes off and forms a brown slurry which you need to wipe off with tissue. Some of the bad rusting was particularly stubborn and needed considerable pressure on the antler and repeated applications of oil to remove it. You can tell when you have managed to get the area clean because the antler slides smoothly over the surface. When finished it still looked a bit marked so I resorted to lightly rubbing the oiled surface with fine wire-wool. Again, more rust came off and gradually a fairly clean surface was obtained. I will give it a week or so for the oil to oxidise then I will finish it off with a coat of wax.
Ian Bottomley

I did think long and hard about how to treat these pieces as well as the consequence of doing nothing. I include a picture of the surface of the helmet which I have yet to tackle. You will note the extensive patches of secondary rusting, some of which are beginning to become serious. Rust is hygroscopic, attracting moisture from the atmosphere and converting more of the iron back to its stable oxide. Left alone, this secondary rusting would eventually have destroyed all of the original russet surface. I could have just covered the whole thing in a sealing coat of oil or lacquer, but to my mind it would have looked terrible. Yes, the treatment might take off a minute amount of the original russet, but very little if done with care. I also include an image of the surface of the mask which has had as much cleaning as it is going to get. You will note the slight etching of the original surface where the rust patches were. Sadly there is no way of restoring this damage, only making it as inconspicuous as possible. I will give it a light coating of wax in a couple of weeks which will help. When new, the helmet and mask would not have been covered in unsightly blotches of rust and I see no logical reason to keep it that way. The only downside may be that the surface looks slightly darker. Even this sis debatable since the original russet would have been oiled or lacquered to preserve it. The ultimate fate of all iron is to revert back to its stable oxide. Short of keeping it in a vacuum, all we can do is to try and prevent it reacting with oxygen and water. This treatment will only last a certain length of time, but at least it delays the inevitable.
Ian B

[RDGAC]

Hah! I got as far as getting the FeCl, but have yet to get round to trying it. Partly this was from caution, partly from lack of a suitable workspace, and partly from a lack of time. We're hoping to get a Heritage Lottery Fund grant for a refurbishment, so (in the hope that we will), lots of frenetic admin activity has been taking place over the past 14 months. It's all excitement and adventure, at least until the money runs out.

I like the look of this process, estrch. I've met Ian - he very kindly came to look at our small collection of Japanese swords from the 2nd World War - and he's a thoroughly good bloke, not to mention exceptionally well-versed in all matters Japanese arms and armour (as you are doubtless well aware). Any preparation with his seal of approval probably deserves a crack; this one, moreover, sounds a lot less potentially invasive than the acid route, albeit far more time-consuming. Only one thing puzzles me - where the hell I'm going to find a bit of deer antler...

- Meredydd (aka Harassed of York)

[Iain]

Antler technique sounds intriguing. New one to me! There seem to be plenty of antlers about on UK eBay. I'm in a rural area myself and shouldn't have a problem to get a piece. The results displayed look promising, however I would imagine steel wool and oil would get the same result?

[RDGAC]

Originally Posted by Iain

Antler technique sounds intriguing. New one to me! There seem to be plenty of antlers about on UK eBay. I'm in a rural area myself and shouldn't have a problem to get a piece. The results displayed look promising, however I would imagine steel wool and oil would get the same result?

Not sure. I've worked this barrel quite extensively with wire wool and oil, and although it's removed the looser rust on the surface, it seems to have minimal effect on the tougher, older deposits. It also struggles to remove rust from pits in the steel. Presumably the antler, especially with that shape, is better for scraping it away without being hard enough to damage iron or steel.

The thought has just occurred to me, too, that these "antler" things have been known to fall off strange, quadruped beings known as "deers". Being a city boy, I doubt such things really exist; however, I hear one can actually pick them up in places, if one knows where to look!

[DaveA]

If you are looking for an abrasive, I highly recommend that you control the grain size. Other members have commented on the need to control hardness and force used when removing rust. Grain size in your abrasive is also important.

I have had excellent fortune with a product called "37-948 3M Micron Polishing Papers" available from Amazon and elsewhere. It comes as a 6 piece pack of 8 ½ x 11 inch papers in assorted grain sizes ranging from 30 microns to 1 micron. They are color coded so you can easily recognize which is which; otherwise it would be very difficult. The particles on the paper are micron graded aluminum oxide and silicone carbide in a slurry that is affixed to the very flexible backing material. When you work with grains at the micron level, it does not leave visible marks and it is easy to control how much material you want to remove by choosing the right size. The smaller grain sizes, when used in sequence larger to smaller, bring a super luster shine to the metal. That said, if you use the 30 micron size with lots of pressure and over a long time, you are definitely stripping more metal off than you should!

The 3M papers are nearly indestructible and the papers can be used again and again. The paper does not rip or separate, even with vigorous use. I typically cut a small piece for easy handling. They work wet or dry, on flat or curved surfaces with ease.

Best Regards,

Dave A.

[Dmitry]

DaveA, can you post examples of the work you've done with the 3M papers? I'm always keen on finding new ways to clean and preserve. Thanks.

[estcrh]

Originally Posted by RDGAC

Not sure. I've worked this barrel quite extensively with wire wool and oil, and although it's removed the looser rust on the surface, it seems to have minimal effect on the tougher, older deposits. It also struggles to remove rust from pits in the steel. Presumably the antler, especially with that shape, is better for scraping it away without being hard enough to damage iron or steel.

The thought has just occurred to me, too, that these "antler" things have been known to fall off strange, quadruped beings known as "deers". Being a city boy, I doubt such things really exist; however, I hear one can actually pick them up in places, if one knows where to look!

Its those raised, hardened deposits that are difficult to remove, I have an old Japanese matchlock barrel that I have the same problem with, it has raised deposits of rust, I did not have any antler available so I used a piece of shaped bone (recommended by another expert), this works well. I was told by the same expert that for really hard to remove spots that he uses a piece of knife sharpening stone as an abrasive, he said this was a last resort and to be very careful as the sharpening stone could damage the surface.

[Dmitry]

Originally Posted by Iain

Antler technique sounds intriguing. New one to me!

Me as well. I sometimes use sharpened pieces of wood, but antler makes sense. It's softer than steel, but harder than rust. Sometimes I coat the surfaces with BreakFree CLP penetrating oil and let the item sit for a week, before I "take the knife" to it. My feeling is that the oil will sufficiently penetrate and soften the rust in that time-span.

[RDGAC]

Bone would likely be easier to get; antler isn't exactly easy to acquire here nowadays, it seems. I'm tempted to see if I can find an old antler walking stick and trim the handle off, but a lot of these are probably plastic nowadays.

In either case, I will (eventually) get round to this, I promise!

Thanks for the tip re: 3M papers, Dave. I think I'm familiar with them as "wet 'n' dry", used to use them for getting a nice, shiny finish on brass controls on steam engines (under advice, might I add, for anyone wincing). I've considered them but think I'd prefer to try the bone/antler trick first, since it seems even less likely to damage the metal. However, I've used wet & dry for some polishing in the past, and it is, as you say, highly controllable.

Best,

Meredydd