Damascus Etching

Posted by: T-Bird51

Damascus Etching - 04/29/06 11:22 AM

I know I have seen it here before and I did a search to no availe, but what is the Radio Shack chemical that I have seen here for black and white etching?
Posted by: Joe Wood

Re: Damascus Etching - 04/29/06 11:30 AM

Ferric cloride which is used to etch electronic circuit boards.
Posted by: T-Bird51

Re: Damascus Etching - 04/29/06 12:07 PM

Thank you!
Posted by: 2-piper

Re: Damascus Etching - 04/29/06 04:52 PM

I recently asked about this at my local Radio Shack & was told they had none & could no longer get it. Others have stated no problem, so perhaps depends upon locale, or even supply on hand. Might want to check soon.
Miller
Posted by: T-Bird51

Re: Damascus Etching - 04/29/06 05:26 PM

Mine had in in a liquid form for 5 bucks. OK so now I have that part. I know that Oscars process was pubbed in DGJ, but those issues are sold out. Anybody have the Cliff's notes on the proceedure?
Posted by: Paul Harm

Re: Damascus Etching - 04/29/06 08:26 PM

They have to order it from their warehouse - and I've been told by my local store they can only get one bottle at a time - something about useing it for bombs , or some such nonsence . anyways , they can get it if they want to bad enough . paul
Posted by: PeteM

Re: Damascus Etching - 04/30/06 08:34 AM

This is a very commmon solution that is readily available. On-line you are can try:

http://www.brainerdchemical.com/BrainerdChemical/Catalog_results.asp?search=ferric+chloride

http://www.alliedelec.com/Search/SearchResults.asp?SearchQuery=ferric+chloride

The MSDS: http://www.mgchemicals.com/msds/english/liquid/415-liquid.pdf

To Dispose of it:
1.)Contact your local Hazardous Waste Disposal Company

2.)The solution must not be put down the drain because of residual copper ions left in it. To make it safe for disposal, you can add sodium carbonate (washing soda) or sodium hydroxide to it to neutralize it, until the pH value goes up to between 7.0 and 8.0, testing it with indicator paper. Copper will be deposited as a sludge. Allow the sludge to settle, pour off the liquid, further dilute it with water and then it can be poured down the drain. Collect the sludge in plastic bags and dispose of it as required by your local waste authority.

Pete
Posted by: T-Bird51

Re: Damascus Etching - 04/30/06 06:45 PM

Thanks to all.

T-Bird
Posted by: Tinker

Re: Damascus Etching - 05/03/06 07:19 PM

I'm interested in seeing those cliff's notes on Oscar's process too.

Does anyone here have a thread link to post for us to see?

I think it'd be great if Dave would create a 'sticky' thread on the topic so that there could be a documented discussion on damascus barrel blacking, browning, and etching.


--Tinker
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/04/06 05:40 AM

Oscar suggested a 15% ferric chloride solution, which I get mixed up by a local chemist. I don't remember exactly, but I think the Radio Shack stuff is 29%, so you'd want to cut it 1/1 with distilled water.
As far as cliff notes go, I can give an abbreviated version of the process.
[1] Coat the bores with something to protect them from the etchant. I use shellac, currently, but expect there are some more modern paints out there that are easier to remove, after.
[2]Rust, boil, and card, as you normally would for standard rust blueing.[No boil, if browning].
[3]Immerse the barrels in the ferric chloride solution for 5-10 seconds, rinse immediately and thoroughly in cold water.
[4]Wet card using 0000 steel wool.
[5]Repeat the process until the desired results are achieved.
______
There are finer points to this. Such as barrel and room temps can effect the outcome, shorter rusting times seem to help with contrast, even polishing is more important than with standard blacking, etc., but that's the short of it.
Also, I built a tank out of 3" PVC to submerse the barrels in, but I believe it was Doug Mann who brushes the etchant on instead. I had trouble getting an even finish this way, he has no problems with it. I'm guessing that a lot of the end result depends upon the exact metals used, and I've not experimented with brushing since that first attempt. I guess what I'm saying is that you're dealing, somewhat, with an unknown here, as far as barrel make up. Go slowly, and pay close attention to detail. Your material will dictate, to some extent, how long to rust, exposure to the etchant,etc.
Jim
Posted by: PeteM

Re: Damascus Etching - 05/04/06 06:06 PM

T-Bird,

Give Dale Edmonds a call at (816)444-2040. I spoke to him earlier this week, as I am sending him a set of barrels to do for me. His prices are very reasonable. He has done a lot of Parkers.

We had a rather long conversation about the process. He started doing it after he read Oscar's articles in the DGJ. He spoke on the phone to Oscar several times.

He has worked out his own unique set of methods. He is very willing to share the knowledge he has. A couple of things he told me. He plugs the barrels with rubber stoppers. The type used by chemists. They have holes in them. He runs a tube up and out of the bath to allow the barrels to breathe. He also said that if he didn't do that, they act like a pressure cooker and the stoppers eventually pop out.

He feels that the blackening process is not an exact science. That as, Jim mentions in his post, there are a lot of factors that come into play. One of the things that he mentioned, was that he feels alot has to do with the type of steel used in the barrels. He feels it may have something to do with the carbon content and perhaps the trace elements that were present when the steel was forged. It takes him about 2 weeks to do a set of barrels.

Like I said, give him a call. He has much to share.

Pete
Posted by: Doug Mann

Re: Damascus Etching - 05/04/06 10:25 PM

Jim, It wasn't me that brushed the etchant on. I don't remember who suggested that method. I do remember seeing Oscars dipping tanks (made from PVC tubing) that was the method that he used. I should have paid A LOT MORE attention.

Doug
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/05/06 05:35 AM

Sorry Doug, you must have been part of the same conversation, or name was similar. At any rate, never too late. The articles are still around, and Oscar derived a lot of info from Angier's book.
__
Pete,
I may give Dale a call. I'm currently searching for a rusting agent that yeilds a lighter than normal color of rust for browning. I've got a couple of Angier's recipes in mind to try, but he may save me some leg work. I'm also curious about plugging the barrels. There isn't a process in refinishing damascus that would require vent holes in the plugs he uses. Boiling water won't harm the bores, and the etchant isn't hot, hence no expansion of air trapped in the bores during that part.
Jim
Posted by: Grampajack

Re: Damascus Etching - 05/05/06 08:14 AM

I got my copies of Oscar's articles directly from DGJ a few years ago. At that time they had one article copied and the other came in a back copy of the magazine. You might try emailing them to see if they still have them. Seems like I paid about 15 bucks for the copies and well worth it. Jack
Posted by: PeteM

Re: Damascus Etching - 05/06/06 10:28 AM

Quote:
Originally posted by JimfromTrafalgar:
Pete,
I may give Dale a call. I'm currently searching for a rusting agent that yeilds a lighter than normal color of rust for browning. I've got a couple of Angier's recipes in mind to try, but he may save me some leg work. I'm also curious about plugging the barrels. There isn't a process in refinishing damascus that would require vent holes in the plugs he uses. Boiling water won't harm the bores, and the etchant isn't hot, hence no expansion of air trapped in the bores during that part.
Jim,

I am sorry.

When he told me that, we were talking about blackening. Whether it is necessary to plug the barrels or not I would not know. I am just an interested consumer.

I know he has used several recipes for blackening. So for the rust process, that may be true as well.

Pete
Posted by: Fred

Re: Damascus Etching - 05/06/06 11:34 AM

I and others were involved with Oscar as he evolved from 15% ferric chloride to 11%, then to 7.5% for some cases (mostly depending on ambient temp -- less concentrated in warmer climes).

Coating bores to protect is fine but he relied on solid rubber stoppers when dip etching. For boiling, each bbl tube got one solid stopper and one with one hole at the other end, with a 90 degree bent stainless tube to vent the bbl interior to air above the water line.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Here are my notes on his process, made with his help:

A Rust Blue Primer
From: Oscar Gaddy

A Slow Rust Blue Primer
With regard to polishing, this should all be done by hand and never with a buffing wheel. The finest that I usually polish is 320 grit. Any finer than this is wasted effort in my opinion as the etching of the steel surface by the acidic rusting agents creates a matte finish with more surface variation than is obtained by polishing with the finer grit papers.

After polishing is completed, the barrel surfaces must be completely degreased before rusting. There are several ways that this can be done including organic solvents and the lime slurry or whiting method. I prefer to boil the barrels in a mild solution of potassium hydroxide which saponifies and removes all greases and oils. The important thing is to use a method that works for you.

After degreasing, the barrels must be handled only when wearing gloves--either rubber or cotton depending upon whether the barrels are wet or dry. The rusting solution is applied to the barrel surfaces. I use a 1 inch wide foam paint brush for this. The rusting solution should be applied as uniformly as possible but it is not extremely critical. The barrels should then be allowed to rust from 12 to 24 hours. Some people use humidity controlled chambers, but I just hang them for rusting in my unheated and un-air conditioned garage. I live in central Illinois and the humidity of the outdoor air is seldom below 30 to 40 % year round which is quite adequate for rusting. Do not try to rust indoors as the indoor humidity is usually too low especially in the winter.

After rusting, the barrels are then boiled in water to convert the brown ferric oxide to the black ferro-ferric oxide. It is always safest to use rainwater or distilled or deionized water if your water supply is very hard. Water with large amounts of some minerals have been known to convert the brown oxide to reddish colored carbonates. After boiling, the excess black oxide is then carded off. I use one of Brownells wire wheels with .005 in steel wires rotating at about 600 rpm. You can also just use steel wool and it is much easier to do this with the barrels wet under running water if you do it this way.

After carding, the rusting, boiling and carding process is repeated until the desired black finish is obtained. The exact number of passes depends upon the rusting solution and the humidity during rusting. Finally, the barrels are placed in a chemically basic solution such as potassium hydroxide or sodium bicarbonate to neutralize any acids that remain on the barrel surface or in pores in the metal in order to prevent any after-rusting. The barrels are then oiled and the bores are polished and the process is complete.
These are the basics of the process. I will be happy to try to answer any questions.


Rust Bluing Formula per Oscar Gaddy Stock Solution; dilute 1:1 … and up to 1:8 for final rustings. To make 125 ml Stock Solution:

Conc. HNO3 ..... 3.22 ml

Hg2Cl2 (Mercuric chloride -- DEADLY poison) .... 6.25 gms

C2H5OH ..... 3.25 ml

Fe2Cl3 ..... 5 ml

H2O ..... to make 125 ml
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Parker Factory Process Adapted by Oscar Gaddy: (DGJ 1997 #2, #3 & 2003 #1)

1. Prep as in Oscar’s original process [next page], Steps 1 – 7

2. “Light” Etch in “mild” Fe2Cl3 solution [I used 15%, it was hard to maintain even results in hi ambient temps of FL – Oscar later moved down to ~ 10%, some report using 7.5%]

3. Rust and card once daily, for 7 to 10 days, as in Oscar’s original process, but no boiling (wet card?) [I dry carded with 0.006 wire wheel, need to check speed, 0.005 or .004 better]

4. Only after 7 to 10 passes, plug bores with rubber stoppers (one in each bore with stainless, ¼,” 90 o degree-bent tube for pressure relief), then boil 5 minutes, in solution of 3.5 ltrs water with 60 cc logwood powder + 30 cc FeSO4 . 7 H2O powder (copperas)

5. Rinse well in cold water

6. Soak ~ 5 minutes in solution of ~ 3.5 ltrs water with 15 cc FeSO4 powder (concentration not critical) – a finger should be able to rub to show light metal with contrast

7. Scrub with CaCO3 powder picked up on wet towel (paper or cloth)

8. Job should look good, but can be improved if desired by rusting and carding 2 or 3 more times; if that is done repeat final steps 4 thru 7. [Parker factory on notes 2nd following page]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


The First Process Oscar Gaddy Published [which I used on Parker D bbls with good results]:

1. Metal repairs as required: Raise dents & peen upset metal

2. Strike damaged areas

3. Hand polish to 320 (up to 400 grit) finish (but more is wasted effort, matted by rusting)

4. Drill 2nd hole in bottom rib

5. Degrease (boil in mild KOH, 0.1 - 0.2 N)

6. Remove remaining finish with Naval Jelly [or Brownell’s version for max polish]

7. Scrub with Ajax, rinse thoroughly and dry

8. Rubber stopper and rust with 1:1 dilution of rusting formula listed above; apply with 1 inch foam paintbrush with excess squeezed out; [make & use rib hole plugs next time]

9. Let stand and rust for 24 hours [but check progress, perhaps shorter time]

10. Boil in distilled H2O for several minutes; dry thoroughly

11. Dry card with 6” diameter wire wheel, 600 RPM, wires 0.006” – minimum pressure against wheel, (consider 0.005” for less aggressive removal or try hand carding next time)

12. Plug with rubber stoppers; immerse in Fe2Cl3 – commercial solution (Radio Shack) diluted to15% strength with H2O at room temperature for “a few seconds” – dilute even more, to 10%, 7.5% or perhaps even 5% at higher ambient temperatures -- [ I later learned that one, longer etch only, before bluing, is OK – see Parker factory process – still ambiguous on this]

13. Quickly rinse in H2O and wet card vigorously with grade 0 steel wool until no more finish can be removed – if not diluting to or below 10% consider dipping into a PVC pipe water tank rinse [rather than hose down] to even out etch time breech to muzzle

14. Repeat steps above as indicated, 10 to 15 times, diluting rusting solution after 2 to 3 passes – typically finishing up with 1:8 dilution for the final rustings – perhaps even lower

15. Immerse in dilute KOH (0.1 - 0.2N) for ~ 1 hour [I repeatedly injected KOH solution into inter-barrel region and sloshed it around], then …

16. Rinse thoroughly, then …

17. Dry, oil, RIG or wax thoroughly, and …

18. Polish bores, muzzle, lump and breech faces
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Parker Factory Process (Unmodified, Verbatim from Parker notes – Oscar, 2003)

1. Clean with brush, heat “on steam pipes” until “fairly hot”

2. Wash with H2SO4, diluted 1:2, for 4 or 5 minutes to bring out the figure

3. Wash with water to kill the acid

4. Clean with pumice and water

5. Apply 1st rusting acid: ½ oz HCl + ½ oz CuSO4 in 1 qt water

6. Apply 2nd rusting acid while first is still wet; formula varied for weather:

Dry weather: ½ oz HCl + ½ oz HgCl + ¼ oz Fe2Cl3 in 1 qt water

Damp weather: ¼ oz HCl + ½ oz HgCl in 1 qt water

7. Place in steam dry[er?] for ~ 5 minutes

8. Put over to the side of the room after drying [to rust?]

9. Turn off “wet steam” after rusted and turn on “dry steam” to avoid too much rust

10. Let stand over night

11. Card with wire brush

12. When cold [implies prior step used power] repeat rusting exactly as before, 4 to 6 times

13. Cook in logwood bath 4 to 5 minutes; bath = 2 qts logwood [probably chips] + 4 to 6 ozs copperas 1.5 ozs CuSO4 in “tank” of water

14. Cool off and place in copperas bath; bath = ½ oz copperas in “tank” of water until finger can rub off black coating to show white, usually ~ 5 minutes

15. “Wash [implies rub] with whiting [CaSO4 fine powder] until figure shows even”

16. Wash under running water

17. Put into tank of hot water, wash well

18. Dry in sawdust

19. Rust again in two acids as before (Steps 5 & 6)

20. Cook in steam room [one time]

21. Cook in logwood + copperas bath 1 to 3 minutes

22. Put into copperas bath, finish as before
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/06/06 01:44 PM

Fred,
It's the boiling that requires no plugs, or coating of the bores. Not being argumentative, and you can't hurt anything in doing so, but it's a waste of time and effort. Boiling water can't hurt anything, this according to Angier and personal experience.
When it comes to the etching tank, something must be done to protect the bores. I had considered using plugs, but got to thinking "what if one leaks a bit?" At that point, I decided I would rather go through the trouble of coating. Done in this fashion, I'm certain the etchant never meets the bores.
My shop is in the basement, approximately 70 deg. year 'round. 15% does quite well, or has so far, but I do keep in mind that with some metals, immersion time or bath strength may need to be altered.
I use a rusting cabinet. Actually, you might call mine an environmental chamber. My day job involves HVAC and refrigeration work. I can control heat and humidity fairly precisely in the contraption I've built. On a Saturday or Sunday,[when I'm there all day], I can get in 4 or so good rustings.
Once again, the premise is the same, but slightly different approaches to skinning the same cat.
Jim
Posted by: Tinker

Re: Damascus Etching - 05/06/06 05:12 PM

Jim-

Can you detail the protols you've found to work in respect to changing the time in the etchant or the molarity of the solution verses the observed effect on the steel?

Is the above noted set of procedures and recipes essentially the same for browning instead of blacking with the only exception being the logwood powder?


--Tinker
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/07/06 08:48 AM

Tinker,
From what I've read, again not experienced, because I work with metal and solution at a constant near 70deg.F, with an increase of 10deg. you can as much as double the effect of the reaction. This in mind, I can understand Fred's need to dilute solution if working in a garage in Florida.
The only changes I've required seem to be related to the make up of the actual metals involved. So far, it's been a difference that is fairly subtle and can be seen after the first immersion and wet carding. I've installed a flourescent light directly over the sink and etchant tank set up. This allows a good view of whether the result is little color left, decent contrast starting to show, etc. From this, I've been able to adjust bath time or rusting solution strength slightly to get better results on the next application. This can cost the time involved in an application or two, if the first result is too little color, but so far, that's about it. I have had one case where you could only push the metals involved to a certain point, or things started getting very blotchy and uneven. On those barrels, I had to remove the finish, repolish, and start over. I then cut back rust time and rusting agent strength, went through more applications to get all the color I could, and stopped the process as soon as subtle signs told me I'd pushed them to the limit. That set taught me that lighting and close attention to what the barrels are telling you is crucial. I might also add, here, that thoroughness in the wet carding is also critical. Anything not done well will show up more strongly on the next application.
Concerning logwood, I've found no need to use it on the black finish. I've tried, and found that, in my opinion, the benefits of gaining color a little more quickly are outweighed by it's potential to take away some contrast. I may try it again, but so far I've just gotten what I needed through more applications.
I've used logwood, in the past, on simple browning, to decent effect, but haven't attempted it yet on brown damascus. The main reason is that I'm looking for an agent that produces a lighter color rust than the one I currently use, first. My Zischang solution tends to render a chocolate brown, and I'm afraid the logwood would turn that to black. When I find the right stuff, I'll shoot for a plum color with the logwood.
When working on the brown finish, Gaddy, Angier, or both, mentioned that at times one would need to rust and card two or three times between etchings. I haven't done many damascus browns, but so far have found this to hold true. Basing the need to etch on the amount of color you retain after carding seems to work. Yes, I'm sure better judgement on this will come with experience.
I hope this answered your questions. I'd like to add that my thoughts on this process seem to run long, and in the end give no black and white answers. This, I believe, is the nature of the process. I might also add that the length of my responses should in no way suggest that I'm an expert on the subject. I'm simply relating what I've managed to learn so far. I'm confident in getting the results I'm looking for, but fully realize that my procedures may change as I run across more potential problems.
Jim
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/07/06 09:08 AM

After responding here, I was checking new posts and ran across Mark Larson's on some barrels I did for him. Those are the barrels mentioned above that gave me trouble concerning uneven finish. As you can see, they could be a bit darker,[to my mind], but I'd rather a more even finish, than uneven and dark. This was as far as I could push them.
Jim
Posted by: Ian Nixon

Re: Damascus Etching - 05/07/06 09:50 AM

JimfromTrafalgar: "but I believe it was Doug Mann who brushes on the etchant instead".
Working from memory now - I believe that was Doug Miller from British Columbia.
Posted by: Tinker

Re: Damascus Etching - 05/07/06 10:53 AM

Jim-

I'd like to hear what your rusting box setup is like. What are you using to monitor and control humidity?


--Tinker
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/07/06 11:34 AM

Tinker,
For starters, if you wish, I can send you some pictures.
___
Picture a normal sized wooden rusting chamber, with a plexiglass front.
A large, 300 watt, lightbulb in the top right hand corner, for heat.
A foot or so from the bottom is mounted an odd shaped shelf that holds the various stands I've made, for barrels and small parts.
Below that is a 5 or 6" fan, set at an angle, to circulate air.
Below that, a heated pan, normally used for condensate removal in commercial refrigeration. It's temperature limited, with a safety, so that if I accidentally run it dry, it won't cause problems. It sits on a stainless steel bottom liner, that is insulated below,to protect the wood.
Left and from the top, is a hook for hanging barrels.
On the right, outside, the controls are mounted:
An electronic temperature control, with an LRD readout, and remote sensor,[located inside,right, rear], that controls the light bulb.
A box holding the relay that turns the de-humidity control,[mounted inside,front right], into a humidistat.
Down low, the main switch, which energizes the fan, as well as the two control circuits.
Up high, a series of three switches that energize the heat and humidity circuits and bypass the heat in case you want to see things on an "off" cycle for heat.
That about sums it up. The humidity control is a bit crude, with some overshoot that must be accounted for because the water pan and water in it remain hot, even after the stat quits calling. The only solution I could think of to remedy this was steam injection, which gets quite expensive. A little fine tuning of the control settings and this is not a problem, however.
I can rust quite quickly by kicking up both heat and humidity, or I can leave the humidity circuit off, and with water in the pan, get slower results if I need to be away, and can't monitor the process.
I can also remove the water pan, and use the contraption as a drying box, for stock refinishing. It keeps dust out fairly well, and the heat and air circulation speed drying time considerably.
The reason I offered to send pics, rather than post them here, is that I just haven't gotten around to opening an account with Photo-Bucket. Should anybody wish to do so, I can e-mail pics, and I don't mind if you post them. I will get around to setting up and figuring the process out, soon, I hope.
Jim
Oh, I don't have a wiring diagram for this thing. It's fairly simple,I just added circuits based on what was required for operation.
Posted by: vh20

Re: Damascus Etching - 05/07/06 09:07 PM

Jim,

Regarding your comments on why the bores would need to be plugged during boiling, I can shed a little light, but not much. The mention of this in Oscar's process only comes up after the usage of the logwood in the boil bath came into play. I do not know what problem this mixture of logwood and copperas would cause in the bores, but that is where the vented plugs came into use. I don't think he ever plugged them when boiling in plain distilled water. I, like you, have boiled quite a few sets in plain water with no problems, but I have not used logwood as of yet. We do plug the bores for the etchant, though.
I am curious about how you go about coating the bores with shellac. How do you do it without getting some on the outside? Does it survive the many boilings without having to be re-applied between cycles? We have always needed a very light bore-honing after completing a set. Will the shellac eliminate this need? How do you get the shellac out of the bores afterwards? Thanks,

Jim
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/08/06 04:58 AM

Jim,
I put a patch in a cleaning loop, soak it in shellac, run it down the bores, then wipe the breech and muzzles. Let it dry, and repeat, twice.
It does seem to change with the heat of boiling, but doesn't come off or appear to break down. In fact, it seems to get very tough. I remove it by running a patch soaked with denatured alcohol down the bores. After it sits for a bit, I run a brush wrapped in steel wool, powered by a drill motor, through. I've made a rod that takes standard American brushes, with a guide that fits in the chamber, for this type of stuff.
Steven Dodd Hughes mentions some type of paint for this purpose when fume rusting. I'm thinking of trying that, as it may be easier to remove.
As far as getting any on the outside. If I had any doubts, a rag with a little acetone on it solves the problem.
Interesting that you plug the bores, but need to lap a bit when finished. I wondered how one could always be certain of a water tight fit, so decided on coating.
I don't think the plugs would be required for using logwood either. I'm not aware of anyone who plugs to hot tank single barrelled guns. You just wind up with a blued bore, which disappears quickly after a little shooting and cleaning. I would think the same true of logwood. I've only used it in the context of scalding browned barrels, and hadn't noticed the bores picking up much, if any, color from that process.
Jim
Posted by: Fred

Re: Damascus Etching - 05/08/06 11:29 AM

Jim, thanks for the clarifications and additional info.

THe Fe2Cl3 concentration reduction resulted from a discussion with Oscar, to address issues I was having. (As you said, reaction rates double for every 10 deg C increase, and my conditions generally ran in the mid 80s.

My problems were slow/poor contrast development and unevenness, particularly "slower results" toward the breech, and also difficulty controlling the etching.

I was dipping into a PVC tube tank of Fe2Cl3 (stoppered bbls of course), holding the bbls by a coat hanger wire thru the hole in the rib extension. It was a quick dip to full immersion, nearly immediate removal and immediate hosing down (literally).

The muzzles had a longer residence time in the bath because they were "first in -- last out," and therefore results weakened going back toward the breech. With a short etch time this became siginficant.

I've been told (but not by Oscar) that he modified his process to use ~ 10% Fe2Cl3, in his later years. I have the impression that this improved contrast somewhat, as well as controlability. In any case it certainly did for me.

I'm about to start a set of Lefever G bbls, here in the moderate clime of So CA, and plan to start at 10%. If anyone has confirming (or conflicting) experience in this I'd appreciate hearing.

Also, I got good results (but needed over a dozen passes) by Fe2Cl3 etching every pass (rusting cycle) -- in the pre-logwood era. The Parker Factory Process states just one, fairly heavy etch at the outset, and Oscar's "Parker Factory - adapted" process implies just one. Does anyone have experience in using just one, pre-etch?
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/08/06 12:28 PM

Fred,
My understanding of the idea behind the pre-etch was that it brought the metals to two different levels. Subsequent wet carding would then be more aggressive on the higher level, more or less skipping over the lower. I don't care for the premise, as it seems to indicate a very strong etching and a tectured finish when done. I didn't pay much attention after coming to that conclusion, so I'm not certain on the rest, but I believe that the normal etching process was followed beyond the first, heavy, pre-etch.
As I said, no experience with that process,but I've seen guns that were, to my mind, too heavily etched. I simply didn't care for the result. The procedures I'm following leave a smooth surface.
Jim
Posted by: Fred

Re: Damascus Etching - 05/08/06 01:16 PM

Jim,
I agree that any different-depth etched look isn't right for American guns (particularly the very apparent different depths that were used on some German guns of the 19th century).

However, I've been fortunate to handle some very high-original condition guns, and have one set of late 1890s Parker D grade damascus bbls in high-original condition (obviously done by the original Parker factory process). There have been no detectable (to the naked eye, anyhow) depth differences in any of these.
Posted by: JimfromTrafalgar

Re: Damascus Etching - 05/08/06 02:33 PM

I don't doubt it. Just seeing the potential is what steered me away from that approach. Oscar mentioned that on some patterns, the pre-etch helped considerably. When I get on a pattern that gives trouble otherwise, I'll probably try an abreviated version of pre-etching, cautiously, however.
Jim
Posted by: vh20

Re: Damascus Etching - 05/08/06 07:35 PM

[QUOTE]Originally posted by JimfromTrafalgar:
[QB] Jim,
Interesting that you plug the bores, but need to lap a bit when finished. I wondered how one could always be certain of a water tight fit, so decided on coating.

Jim,
I figured you would pick up on that. I don't know if the plugs leak during the etch dip/rinsing/wet carding or not. But constant immersion in the boil tank, neutralization tank, and rinse water (even with immediate drying) in our humid Alabama climate every day for over a week and no oil to protect them will result in some stuff growing in there regardless. We do unplug the bores for the neutralization tank and rinse water just in case the plugs did leak in the etchant tank. I like the idea of protecting the bores with a coating, and appreciate the advice.

Jim