The text says tensile strength. I can’t imagine it wouldn’t be much stronger than the original rubber links.
can you scavenge parts from this watch band?
I don’t know anything about such things so I looked up tensile strength of some common materials here. It seems that it is measured in mega pascals (I think that’s what the MPa is anyway).
So I went here to convert psi to MPa and found that 4000 psi is about 27 MPa which is in the same general ballpark as polypropylene. That’s ok I guess, but there are too many other things I don’t know about the material and there is a lot of work involved in doing this so I’m probably going to want to go with something I’m a little familiar with.
Thank you for looking, but I tried looking myself a while ago. This watch requires it’s own custom band because of the way it attaches to the case. The band is part of the face/facade/whatever you call it, so there’s really no way to substitute something else.
I know you were suggesting using it for parts, but I didn’t see any links there, which is what I would really need. Plus the odds that they would be just the right size . . . well, you know how that usually goes.
You know, the more I’m thinking about this and the work involved, the more I’m thinking it might work fine as a pocket watch - in the sense of a watch that I put in my pocket and which doesn’t need a band. Or I suppose I could always go kicking and screaming into the 21st century and just use my droid. I’m sure it’s powered by dark magic, but it’s not as if I still have a soul to lose.
Sterling silver tarnishes like crazy.
I’d look at using the precious metal clays- that way, you can sculpt and drill what you want, and when you’re done baking it, you have a finished metal part.
http://www.riogrande.com/Category/Metal-Clay-Glass-Enamels-and-Resins/114/Metal-Clay/5756
Wow, I’d never even heard of that stuff. It sounds amazing. The shrinkage part bothers me a little since I don’t eyeball things very well, but I can probably work around that.
The other thing is the sintering part. I’m guessing that to get the whole mass to bind together you’re going to have to get pretty close to the melting point, but then how much margin of error do you have? Or can sintering happen at lower temps? Sorry if that’s a stupid question.
About sterling - now that you mention it, that sounds familiar. I don’t wear jewelry except rarely, a few things in Bali silver and I know that those do tarnish when they’ve been sitting.
The problem is that my only other choice is gold and then the watch looks like some cheesy Rolux [sic] knock off. Oxy-propane is only good for a subset of the things I would like to use and it would be stupid for me to buy any real equipment for a project like this.
Anyway - very cool stuff that metal clay. I’ve bookmarked both of those links.
several posts previous, I pointed out how bad precious metal clay would be for this application. It’s way too porous and weak, but it is cool for use in other ways.
What you want to do is use a silver rod that has a rectangular cross-section, and then cut slices of it with a jeweler’s saw.
something like this:
Silicone, you can have undercuts and use the mold quite a few times. The cast surface is smooth.
Plaster, if you have any sort of undercut the mold has to be destroyed and remade each cast. If its at all wet, the thing explodes. Not as fine when cast so you have to do more work. But generally cheap and effective with care.
You can also sand cast, which is fairly easy but seems to take a knack! Or cash with a cuttlefish bone, where the original is pressed into the soft cuttle-bone and the mold used once, it smells foul though and gives a textured surface that is good on some jewelry.
Melting wise,you need a crucible or something with a higher melting point that silver to melt it in and a gas torch. Torch needs to be able to get up to temperature, you can do that with propane which is he cheapest option. Mapp gas torches are super hot and available at normal shops or acetylene are much hotter but takes special arrangements to use.
I’ve done lost wax casting with (lead free) pewter - but nothing yet as finely detailed as the parts you’re describing. Lost wax casting increases in difficulty as you pick metals with higher melting temperatures - if only because the integrity of the mould needs to be greater, to stop it exploding or catching fire.
However, metals with lower melting points tend to be softer and more malleable, so it’s a tradeoff.
Am I right in thinking the link pieces you need to make are sort of rounded-rectangular with a pair of holes through?
If so, and if it were my project, I’d probably try to cut and hand-machine them out of a solid bar of maybe aircraft-grade alloy or something.
Make a hardwood jig so you can just push the end of the bar into it to a stopped end
Add a metal plate on top of the jig, with guide holes for drilling, and a slot or edge for scribing off a cutting line
Then it’s a case of insert bar >drill, drill > scribe >remove bar> cut
Repeat as required until you have the necessary quantity of blanks
Maybe make another jig with a couple of protruding pins onto which you can slot the blank to work on it with small files. Make a sort of stencil type measuring gauge that you can keep trying to slip over the part to determine whether it’s down to the right size.
Finish by threading the parts onto stiff wire and polishing with fine steel wool and/or a rotary buffing wheel.
Just thinking though… with silicone moulding material, you can make a mould from an intact original part - because the stuff is flexible enough to spring back when the original is (and subsequent copies are) pried out - casting might be a viable option in this case.
As you’d be casting using a different metal to the rest of the band, there is the potential to set up a galvanic reaction which could result in rapid corrosion of some part or other, but I’m not sure how to predict that.
Finally… have you considered the option of making just two new parts - that is, make a pair of adaptor links that fit onto the casing (or first available attachment link) and enable you to fit a standard watch band?
How about getting someone to model the link shape, then using a 3-D printing service to fabricate the links from the model? Models can be fabricated in many materials, including flexible plastic, rigid plastic, and various metals. Metal pieces can be polished to a high shine.
Sorry about the clay reference. Probably what happened was, it didn’t register as I had no idea what it was, so I missed it completely. Thanks for trying though. It’s always rough when you don’t know bkgrnd of your audience.
And I like the rod/wire/tubing idea - more anon.
The measurements for the links are 3.56mm w, 4.06mm deep (from top surface to skin surface) and 7.77mm long. Of course since they’re rubber, the 2 decimal precision is questionable, but I tried to get close to what a rigid structure should be as a substitute.
I think I’m going to use thick walled gold tubing. The width and depth are close enough that I can squeeze it to fit. Plus, since it’s tubing, it will be both cheaper and easier to drill.
My only concern is the durability. I’ll probably want to get a very high alloy content - I guess 10k or something - but I’m not sure I have a lot of choices. Opinions?
I could really use recommendations for stateside retailers. I’ve found a few online, but their selection tends to lean heavily toward crafts rather that real jewelry makers so there’s lots of wire and low end product, but not much selection for something like gold rods and tubing.
This is going to get a little expensive. It seems I’ll need at least 6.5" of tubing and I think that’s going to be somewhere in the $150-200 range. This might be the point where I ask myself if I really want to do this. I am thinking about it btw, but I really like that watch. Actually I have another as a backup, so even if this one dies, I’ll still be able to use the band.
The only aesthetic issue will be those black rubber shoulders around the bezel (that are part of the band). If I can get white gold, it won’t look so bad, If I have to get yellow gold, that might be iffy.