tera
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Post by tera on Apr 13, 2024 5:08:12 GMT
In my thread chronicling my adventures in custom tsuka made by an Ali Express seller, the lack of truly custom fit to nakago came up.
This got me thinking dangerous, blasphemous things.
Could one use a form of epoxy or wood putty to "Bed" the tsuka to the nakago like one does a rifle action and stock? Keep in mind we're talking $30 tsuka for $1-350 sword range here.
One mechanical problem I see sucks. No, literally. When bedding a rifle, you have the action (usually tubular, but sometimes with corners) laid into a valley (in the stock). With a blade and tsuka, you have a stick in a hole, with no vent. This means you're creating a vaccum with a tight fit. It's troublesome to pop a rifle out of a stock even if you use adequate release agent, but getting a nakago out of a tsuka once a vaccum has formed by the hardened compound? Sounds extra tricky.
Has anyone been crazy enough to try this? What were your results? Do you know better than to try this? What are the structural/mechanical reasons it is to be avoided? Is a loose nakago fine as long as you have two solid mekugi?
What say you all?
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LeMal
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Post by LeMal on Apr 13, 2024 7:47:11 GMT
This is off on a bit of a tangent, but if you're going to use epoxy putty (and certainly if unhappy with an existing handle) I've formed entire handles directly to tangs with just the epoxy putty itself. Then just file and sand to final shape and put on your preferred covering.
Another odd modern option I've used but now absolutely love is to make a mold, e.g. of plaster, of the handle you like and then make one directly to the tang by way of hot melt adhesive. (Then just put your leather on, or in my case usually a layer of rawhide then one of leather.) Not that far off examples of e.g. Indo-Persian hilts of hollow metal filled with a cutlers resin.
A little far afield in regards to katana, but hey, if you're already experimenting on more budget pieces, figured I'd throw a couple odd options out there. ;)
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mrstabby
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Post by mrstabby on Apr 13, 2024 7:56:31 GMT
I don't think vacuum is the most problematic here, the epoxy will grip onto the imperfections of the steel even if you put oil or mold-release on it and might act like lego. I have bedded a few grips with epoxy and epoxy putty, the putty does not stick to the steel as well, and you can lift it off very easily, but moving it along the tang is harder because it grips onto the surface, unless it has a relative high polish and some oil. Well I did 2 grips, but I experimented a bit on the bare steel. With a polished steel that is oiled or waxed or vaselined, the glue won't hold onto the steel at all, you can feel the vacuum but the oil seems to make enough space so it can be broken when you go slow. On rough steel, like 80 grit finish or if there is a rough patch from old corrosion, the space created by the oil isn't enough, I guess the epoxy creates matching negative peaks and valleys.
You could try paraffin wax, a thin coat that makes the thickness and surface uniform, epoxy it, if it does not want to let go you can warm it to melt the wax. After removing the wax it should fit pretty tight, depending how thick of a wax surface you built up and how uniform the dimensions of the steel itself are.
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Post by larason2 on Apr 13, 2024 23:12:25 GMT
Usually when tangs are epoxied onto, you don't want it ever to come off! This is a clever idea though, but yes if you're not careful you may have trouble getting it off. I'd either file or polish the tang down some more after casting, or sand/carve the surface of the epoxy some. Filing the tang is the easiest. Carving or sanding epoxy can be tricky, because depending on the epoxy and how much air it had/has access to, it can take weeks to cure. If you try to sand it too soft, it will just gunk up your paper, whereas if you try to carve it too hard, it will be a nightmare to carve! I'd probably wait until it's cured and sand, while also filing the tang somewhat. A bit of Column A and Column B!
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Post by Cottontail Customs on Apr 14, 2024 1:22:58 GMT
considering the quality, or lack thereof, of the premade tsuka and tsukamaki, I would probably avoid the extra effort and just glue it on permanently. when it comes time to change it, I would just chisel it off the nakago. I've removed the tsuka from a few Hanwei practicals like that and it wasn't that difficult. in my opinion, it would be safer overall.
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tera
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Post by tera on Apr 14, 2024 5:01:05 GMT
considering the quality, or lack thereof, of the premade tsuka and tsukamaki, I would probably avoid the extra effort and just glue it on permanently. when it comes time to change it, I would just chisel it off the nakago. I've removed the tsuka from a few Hanwei practicals like that and it wasn't that difficult. in my opinion, it would be safer overall. This is good to know, and a wise point. I know these will not come close to your work, so I'm trying to manage expectations. This is an experiment to see what is possible at the bottom tier. For those tracking my other thread, this is what I was really lusting over, but alas: cottontailcustoms.com/skyjiro-tsuka-makeover/Safety is a strong concern so this may be the best approach for a bargain bin tsuka. I appreciate your input as always!
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Post by Cottontail Customs on Apr 14, 2024 14:19:51 GMT
I was focusing more on the quality in terms of safety and durability of the tsuka more than traditional technique and aesthetics. Some of these premade tsuka can be made from very poor quality wood and have loose maki, so for the sake of safety, I’d probably want an ill fitting handle of that quality to be as secure as possible. If it were higher quality all around, I’d possibly think it was more worth it to be removable and have the same functionality as it normally would. If that makes sense. I’m thinking it might be something like why Hanwei decided to go that route with the basic practical line. Lower quality parts and construction to keep the cost down but safe and secure nonetheless
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mrstabby
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Post by mrstabby on Apr 14, 2024 14:51:34 GMT
Yeah, don't underestimate bad wood. If the drying was done badly or the wood itself is bad at worst it could shatter from any impact, a tight glue joint would prevent this. Although having to chip it off in the future can't be much fun either. You could also try putting the epoxy on the tang, fattening it up and filing it down to a good fit. Probably the safest option is, as Cottontail suggests, to glue it all together tightly and break it away if you were to put a new grip on it.
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tera
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Post by tera on Apr 14, 2024 23:17:29 GMT
I definitely appreciate the safety focus from everyone. I'm fully aware I may toss these in the bin as soon as I see them, and that even if they "look" ok assembled, the wood is a big unknown.
Now I'm contemplating appropriate epoxy, and realizing my Munetoshi may be a long-term project. I have a steel tsuba blank I'd like to carve some designs into with a graver. Epoxy means I have to complete the tsuba before installation. I may drill for the mekugi for test fit, but not even practice cuts until all is locked down.
As a general caution for folks following this, know this will NOT be artisan work and the experiment was driven as much by the low availability of REAL tsuka work as any price concerns. If folks like Cottontail Customs start taking orders again, that is absolutely your best option. 👍
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