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Francis Gastellu

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Posts posted by Francis Gastellu

  1. I did some tests today with several different alloys in an old solution (used on 3 previous occasions, initially 4g rokusho, 4g copper sulfate, a pinch of borax and one of alum). The pieces were:

    - 260 Brass: 70% Cu + 30% Zn
    - 230 Brass ("NuGold"): 85% Cu + 15% Zn
    - Nickel silver: 60% Cu, 20% Ni, 20% Zn
    - C145 copper: 99.4% Cu, 0.01% P, 0.6% Te

    ...as well as what was probably a mistake, which I only realized after the fact:

    - 954 Bronze: 86% Cu, 10% Al, 4% Fe (!)

    I didn't realize the bronze I had was aluminum bronze, which contains iron, known to ruin the niage bath. I had not planned to reuse the solution for anything after that, but it's likely to have changed the effect on the other alloys, rendering this whole test dubious.

    This is still an experiment I suppose, so for the record, here were the results:


    From left to right: 

    - copper got substantially darker in 1h than in my previous experience, and has a *very slight* blueish tinge when viewed in the shade

    - 230 brass immediately went blue/grey, and shifted to nutty brown in about 20m with little change after that (just a bit more saturation)

    - nickel silver was similar to 230 brass for a good while, but ended up somewhat reinforcing its blue tinge over time, resulting in a brown that tends toward bordeaux (quite pronounced when viewed in the shade).

    - 260 brass went from yellow to orange, with a really satisfying tone at about 30/40m, then slowly got darker and closer to 230 brass, only slightly more redish.

    - 954 bronze did its own thing: it was entirely unaffected by the first 20m and then developed a yellow/orange color. Though the blotchiness is likely my fault for not polishing well enough, i suspect the "bubbles" are casting defects.

    It's pretty much impossible to take a photo that accurately portrays the colors the eye sees under different conditions, so here's another one with different shades while the pieces were still in the cooling water bath:


    For reference, here are the unpatinated alloys:


    I'll be trying some of these again in a more controlled run (new niage bath, no iron, and C110 copper instead of C145 for a better baseline). It'll be interesting to see the difference when iron isn't added to the mix :P 

  2. Thank you Jim, so much to learn and I should probably pace myself a little bit :) 

    On 6/14/2021 at 9:07 AM, Jim Kelso said:

    I would focus on smallish works, as you are, and combinations of colors, and move on with what you learn

    Agreed. For the piece I am working on now, I am combining what I've used in the past with shibuichi 40/60, which I haven't used before. It's one thing to think "light gray" and "dark grey", but it will be interesting to have a piece that actually shows them both in contrast to each other, and to silver.

    I should be able to do some patination tests this weekend on a number of additional alloys, I'll report my "findings" here. Perhaps this thread can continue to capture more of my notes in the future, as well as comments from anyone else who's knowledgeable and/or interested.

  3. I had some fun trying to carve a swallowtail butterfly at about 1/7th of its actual size :)


    Originally just a practice piece, I'm now looking to inlay this into a larger composition. This is shibuichi 20/80, so should patinate fairly dark. 



  4. Being fairly new to irogane and rokusho patination, I'm trying to get some understanding of the basic color palette that is available to me when planning a composition. Although I have been able to find some good information here and on other sites, I was hoping that people with more experience could fill in some of the gaps in my understanding (or correct it if it is wrong!).

    I only have (limited) experience with copper, 20/80 shibuichi, fine silver and 24k gold. My current notes have the following:

    - Copper will shift color from orange to brown and eventually to red given enough time (~8/10h). I have gotten good orange with as little as 30m, and a (still orange-ish but) decent brown after 1h. I have not chased after the elusive red just yet.

    - Shibuichi will give light grey to dark grey depending on copper/silver ratio, and takes about 25/30m. I have only used 20% silver so far, and gotten quite a dark shade. My understanding is that increasing the silver content yields a lighter color. In addition, Jim Kelso details here a process of silver enrichment, which can achieve gradients between light and dark areas on shibuichi.

    - Fine silver will not change color, but may develop a yellow film on the surface after some time. A pinch of alum can help avoid this according to some sources, though I have at least once seen this film form regardless (as I said, I'm new at this, and so is my copper pot!)

    - 24K gold will not change color, I do not know about lower karat.

    - Shakudo (no personal experience) will go black with a deep purple hue at around 1h.

    I have found little information about rokusho on brass or bronze. I plan on experimenting some (including non-traditional alloys such as nickel-silver), but an idea of what to expect would be useful as a point of comparison. I have heard that one should use a separate niage batch to patinate brass, but I have not heard why (I imagine this is due to the Zn and also applies to other Zn-containing alloys, but I don't know what that actually does to the solution and why it should be a separate batch). In addition, this would seem to preclude patinating a multi-alloy piece (say, shibuichi + copper + brass); is this simply not done?

    I'm also quite intrigued by the silver enrichment process for shibuichi, though it's unclear to me how the enriched layer is preserved given that the patination process begins with polishing the entire piece (abrasive powders, and/or charcoal). I am guessing that the polishing step can leave enough of the enriched layer alone to still achieve the desired result, and that experience teaches how deep that layer goes for a given amount of heating/pickling cycles (and I suppose for a given silver/copper ratio). I'm also wondering if a similar process can be used on other copper alloys: if oxidation mostly affects copper, then brass/bronze, and even shakudo may also be affected in a similar way, perhaps yielding useful color gradients?

    Finally, am I missing some of the basic colors in the palette? For instance, I really really wish I could achieve some form of green (i believe I could with different chemicals than rokusho, but combining that with rokusho-based colors would seem extremely challenging if not downright impossible)

    Any information/correction on any of the above would be immensely appreciated.


  5. I'm sure someone with more experience could comment, but I've seen these on wood and metal alike. From what I can tell, changing the angle of the file and/or the pressure tends to make those go away, and I my feeling is that this happens when (even a slight) chatter and the angle of the file teeth get together "in phase".  Caveat: I don't really know what I'm talking about :blush:

  6. On 6/5/2021 at 2:14 PM, Janel said:

    (Bladesmith's early founder Donn Fogg, joined and encouraged Jim Kelso and myself as co-founders of The Carving Path forum.)

    I am so glad he did. Both forums are incredible resources, even for people like me who are a little late to the party. Thank you! :) 

  7. 1 hour ago, Ed Twilbeck said:

    Excellent work, fantastic ,would love to see the sword. Thanks for sharing.

    Thank you so much Ed!

    Here's the tsuba mounted on the sword. 


    There are a couple more carved/inlaid elements:




    For anyone interested in the other aspects of the build, see this thread (in another forum, I hope that's okay to link to).


  8. On 5/28/2021 at 2:43 PM, Pavel H said:

    There are winners and there are losers .... 😉


    Unless the other three sides all have 1's, it seems to me there really are only winners ;) Love the concept :) I really like those little carvings!

  9. Thank you so much for the advice. I have this kind of wheels but did not think about using them that way! I've used bullet point silicone rotary polishers with good results, but it took me some time to accept that using them for this purpose with the rotary tool, even at slow speed, was just asking for trouble ;) 

  10. I've recently completed a japanese blade, and I thought I'd share the tsuba (guard) here. It's the first time I do this kind of inlay on that scale. 




    The young vs old bamboo dichotomy symbolizes growth, while the waning and waxing moon stand for the opening and closing chapters of our lives.

    I spent most of the time on the obverse side with its many inlays, and I made more than a few mistakes. There are still visible signs of my crimes, but I'm (mostly) okay with where I ended up.

    The reverse side features a simple katakiri carving. It doesn't look like much, but balance and confidence in the cuts were my main goal. I practiced many times before I let myself do it on the real piece. This version turned out better than any of my practice run :)

    These photos were taken just after the patination bath in roksuho.



  11. Thank you Ed for your answer and suggestion. I will need to try this out, though the scale of my work will add its own challenges, but I can see how this might be a good way to get inside those very tight spots. Thanks again!

  12. Thank you Janel for your reply!

    I have been an avid follower of Jim Kelso on the web but did not realize he had more of his work on Instagram, thank you for this!

    I think you are right that scrapers are at least a part of the answer here, and I'm right now looking at different geometries for this specific job. When it comes to polishing to a finish though, I think there is (at least for me) a bit of a gap between that and being able to move on to powdered abrasives. I've been somewhat able to bridge the two with shaped stones and toothpicks wrapped in sandpaper, and I am still experimenting with other options.

    For instance, I've had some measure of success with a custom 1/16 rod sharpened to a point, with just one facet:


    This acts as very mild bur as well as a burnisher of sorts. It needs to be used with the lightest of touches, and still doesn't quite leave a smooth finish, but it's been helping me get the floor of those corners flat, leaving a texture that's not as hard to deal with as what was there before, if that makes sense. I use this after scraping, and before stones/sandpaper/powder. 

    I got started on the actual project, and this is where I'm at (silver inlay on shibuichi):


  13. Well, I managed to shape a couple stones to a tight point, and I made myself a needle shaped burnisher. Combined with the careful hand use of gravers as scrapers, and more patience, I got to a better finish in the inside corner.


    There are still issues here obviously (background flatness, and the rounding of the foreground due to my indiscriminate use of sandpaper without hard backing), but I was focusing on the tight corner and that's a lot closer to what I want (this is just a practice piece).

    Additional tips are still welcome :)

  14. Hi!

    As the topic says, I live in California. What the topic does not say is I'm actually French :) I am a hobby knifemaker and more recently swordmaker, and I have developed an interest in Japanese metal carving through the need to make koshirae for my blades. I am in awe when I see the work showcased in this forum, and I see that there is a long road ahead and much practice needed to eventually do some of the things I want to do. I have been lurking around for some time now, and I thought it was time to finally sign up. I hope you will forgive my beginner's questions! :blush:




  15. Hello everyone,

    I am fairly new to tosogu and currently working on a tsuba. Part of the design calls for carving out some of the background, and I am practicing polishing a smooth slope and its transition with the foreground features.


    As you can tell, the closer I get to a border or to a tight corner, the more I am struggling, and I am looking for advice on how to effectively cleanup and polish close to details that need to be preserved. The tight inside corners are particularly challenging. I do have small stones, but nothing that small. A small piece of sandpaper wrapped around a toothbrush just about gets in there, but lasts about 2 seconds and I'm thinking there has got to be a better way :P or is there?

    I have read Jim Kelso's turorial on file and stone finishing, and that has been helpful in dealing with larger areas (thank you Jim!). I can see how I could eventually get the surface next to those details cleaned up with just a bit more patience, which I'm more than willing to exercise, but I'm doubtful that I can effectively deal with the tight inside corners that I'm currently struggling to even reach.

    Hopefully someone can point at an element of answer, thank you!

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