PValBlanc

Don't make me laugh with a sip of coffee in my mouth Charles. :p

Charles, wouldn't that just be a convenient way of stropping? (Provided you don't have anything abrasive in your Jeans, such as grind belt residue...)

I'm once again, late to the party. All the most important stuff has been said here. I'll just add a personal pointer. Seeing as how you mention both razors and kitchen knives. The essential difference between the two will be the level of polish. A kitchen knife needs to be a little less polished, because on a microscopic level, you want the edge to retain micro serrations. These micro serrations allow the knife to bite into what you are cutting, rather than glide on it. For instance, an over-polished kitchen knife will tend to slip on a tomato because of its skin, rather than cut into it like it isn't there. I've found my sweet spot on japanese stones for kitchen knives to be around 4000/6000. For a razor you need to polish it further. Hence the whole 8000 and strop, and the much feared honing process. A razor needs to be highly polished in order to eliminate said micro serrations, mainly because you want the razor to glide on your skin, certainly not tend to bite into it. That's essentially the tl;dr of edge properties as was explained to me by a guy who makes a living sharpening kitchen knives and straight razors with japanese water stones. His advice was gold. My sharpening skills saw a lot of improvement anyways. Hope this if of help. -Cheers Pat.

Currently, spme fairly basic torque plates without the die and punch section, but lower expansion bolts than the plates themselves. I don't remember the specific steels, I just trusted the machinist who made them with that. How pressure can decrease anyways? That's a good question, although testing has shown it does, according to James Binnion's team anyways. He's written some papers on the thermal expansion mismatch torque plates for the santa fe symposium if you want a expert's opinion. I'll proceed to go reread those, because your question, sir frosty, may well kerp me up all night if I don't find the answer

Well under eutectic. Perfect. All the info so far points in the same directions. Thanks a lot. This will be a great help.

More specifically, the atmospheres are different within a heating electric kiln and a gas forge, leading to different kinds of oxidation/decarburization issues, and as such, different solutions. I am not well versed enough in gas forges to elaborate on that, but there is another big point of difference. You can heat treat virtually any steel in a controlled kiln. With any type of forge, maintaining the precise temperatures for the necessary soak times (of multiple hours) for proper treatment of stainless or other forms of highly alloyed steels is next to impossible. As such, if you plan on using mostly carbon tool steel, the forge will do fine. But the kiln would be an essential for higher tech steels. With a bit of mcguyvering, you can use a good heat treat oven for a bunch of other stuff too: burnout (for lost wax casting), enamel, mokume, melting for copper alloy brewing... And so on. I hear gas forges are pretty versatile too, but again, not my area of expertise, not yet anyway. Hope this was of help!

teeny, Cool, I'll be sure to keep an eye on the thread. Timgunn: That's interesting, I'll have to make due with the charcoal and foil variant of reducing atmosphere, I don't have the means for nitrogen. That said it shouldn't be a problem. 700 is a nearly a full 100 degrees below eutectic, so it shouldn't be an issue either way, sterling and fine silver should both behave similarly at those temperatures. Thanks for the tip, if nothing else pops up, I'll know to start the tests below eutectic rather than below liquidus. Between you and teeny, I've got two opinions pointing in that direction.

Can't be time then. Clamping issues huh. What kind of Torque Plates are you using? Your average torque plates release pressure fairly early in the firing process because of thermal dilation. You can build Torque plates to counteract this. Essentially, you want your bolts to be made of a steel with a significantly lower coefficient of thermal expansion than your billet and plates. Bolted in the middle of the plates you use a die with a rectangular cavity in which to fit your billet and a punch to fit the billet. The punch needs a higher coefficient of expansion than the billet and die. The result is maintained pressure on all three axis' on your billet. It also cuts down on oxidation. tis a pain to make though.

So I'm new to the forums, if not new to metal. I'm a craftsman from Montreal Canada. Here to drive you all crazy with metric measurements Seriously though, I've a degree in jewelery making and have spent the last few years focusing on knifemaking. I've also dabbled quite a bit in watchmaking, mokume gane, lapidary and whatever else I could get my hands on. I'm glad to be among you.

Ah, I misinterpreted the tone here. Sorry. Essentially, I haven't attempted a billet in the kiln yet (as I feel I lack this basic piece of information) and as a thouroughly scrapped mokume billet is usually a lot of money down the drain, I'd rather do my homework first. So long story short, my experience is limited to torch fused billets so far. Kiln, torque plates, steel foil, charcoal and all is covered. I just need a working idea of how to determine temperature to bond two given metals (i have phase diagrams for most of the relevant ones). Edit: I failed to specify, the kiln is a knifemaker's electric kiln, quite precise for temperature control, but on the poor side for atmospheric control (hence, wrapping the billet and torque plates in a steel foil bag filled with charcoal,to cut oxidation).

I'm a little late to the party here, but I've found the challenge with shibuichi is the amount of oxygen it drinks from the air in the melting process. I've found the cheapest upgrade to a shibuishi setup is a graphite crucible, it helps loads with creating a reducing atmosphere. The next step up, if you've got the kiln, is kiln melting it instead of torch melting it, but I've done fine with a torch and graphite crucible. cheers.

Thanks! In my experience any form of mokume billet is prone to failure until about 66% reduction. Or rather, you can't be sure your firing was successful until you've reduced about 2/3. I guess the one thing bugging me about the whole question surrounding the eutectic point, is it shouldn't be a concern if nothing melts. And if you're heating up to say 840C in a controlled heating kiln (I'm using the my knifemaking heat-treating kiln), you're still 50 degrees under the melting point. There's no reason for it to melt, unless your kiln is unreliable, or your alloy proportions are off. That said, how long did you soak your billet at temperature for in your mostly unsuccessful run? Inderstand ss diffusion bonding soaking times can be as long as 8 hours. I did check the libraries Glenn, and it doesn't seem to be an option. And while I do understand the value of experimentation, this is something that people have done before, and so clearly, answers exist. I apologize if my question is too basic and as such has attracted such an aggressive response. It was not my intention to frustrate anyone. The question just didn't have a definitive answer within the forum thread, and seemed like a pertinent one, both for me or anyone browsing the forums in the future.

Hi, This would be my first time posting on these forums, and I need some help. I've my share of experience with liquid-state torch fired mokume, and am setting up to try my hand at kiln fired solid-state diffusion bonding instead. I've found most of the information I need except one vital detail. I can't seem to find any guidelines on how to select temperature for bonding. Let's start simple here and suppose a sterling silver/copper billet. Sterling melts at 893 C Copper melts at 1083 C Sterling is a hypoeutectoid alloy at 17.5% copper The Eutectic point of silver/copper is at 28.1% copper and around 790 C So here's the question. Do I want to be heating my billet a little under the melting point of sterling, seeing as it is the lowest melting point? Should I be heating a little under the eutectic point? Not sure if the eutectic point is relevant if nothing is hitting liquidus. Perhaps none of the above? Any advice would be greatly appreciated. I can't get my hands on the midget/fergusson books, and most other sources I find all take for granted you've got the basics figured out. Cheers -Pat.