Pendray wootz in progress

Bruno

Bruno

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I am making a pendray wootz razor for @Mike Blue . And another for myself / for sale depending on whether someone wants it when it is finished or not. I started with the rightmost blank in the picture. It weighed 260 grams.

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First i drew it out until it was 5/8 by 1/4 and 10" long. I did that by hand because wootz and presses are not best friends. At least not for small cross sections. Then i cut it in 2 identical pieces.

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And then i carefully forged those pieces into near identical razors. One weighs 114 grams, the other 118.

There is very little spare material in these blanks. Normally I am slightly more wasteful but i really wanted to get 2 full razors out of that piece of steel. Pretty happy so far.

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Bruno

Bruno

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Staff member
I did the rough shaping today. The hollows are ground,.and the overall shape set. Slight humpback like the Frederick Reynolds. It will also get notch point.

These will be as identical as i can make them. Normally I would not stop at this stage but press on until they were polished, jimped, notched etc.

But given that i had been focused for more than 2 hours already and maintained perfect identical geometry, i decided not to press my luck and risk an oopsie with a cost of 4 figures.

So far i am very happy with the progress.
Note that the angle of the picture make it look like the bottom razor is curved differently. I assure you it's not. The bottom one is a perfect overlay ofvthe top one.

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Bruno

Bruno

Administrator
Staff member
This is all the pre - heattreatment work done on my Pendray wootz razors project They're still as identical as i can make them. Even the jimping lines up between them. I've decided that I am going to follow my latest understanding about wootz carbides and do a water quench. I am at the same time excited and scared. Excited because the pattern should have an even bigger contrast than the other Pendray razors I made yet. Scared because water quenching is a tricky and sensitive process and I am dreading hearing a 4 digit ping.

I have taken a number of safety precautions I don't normally take. I sanded the hollows with a worn 120 grit belt, and rounded the edge, polished the edge, and smoothed the barbers notch on the inside. The idea is to avoid any and all stress risers. Normally I would not do this because it's not truly necessary if you quench right. But it would suck beyond belief to hear a ping and then say, you know, I should have polished the edge instead of leaving that grinding scratch...

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M

Mike Blue

Member
Confidence Grasshopper! Perhaps the physicist's would call it quantum entanglement these days. But if you know it's going to work, it works. It's when you doubt that funny things happen.

I'll bet on confidence, even from here and you there. We've both handled that bar of steel. It's all gone well so far, why should it break when so many want to see it completed successfully?
 
Bruno

Bruno

Administrator
Staff member
First I was going to do the HT on friday afternoon. But it was a dreary day. Rainy, windy. It didn't feel like the right day.
Today I had ample time, it was sunny, no wind, and felt like a good day for heat treatment.
I water quenched both razors, and didn't hear a thousand dollar ping :)
Both razors survived perfectly fine, and showed nice carbide banding to the naked eye which I hope will show up after etching.

They are already tempered but I need daylight to take pics. Hollows under LED lighting look like crap.
 
Bruno

Bruno

Administrator
Staff member
Well Mike, I seem to have learned enough about wootz over the years to understand the carbide formation and the heat treatment. This is during finish grinding, 120 grit, no etching whatsoever! The carbides are so strong I can just see them without etching. The patterning on our razors is going to be awesome.

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Aside from the nice carbides, you can see it auto hamoned during quench. The blade hollows were hard completely on the outside. When I started grinding, everything sparked. As soon as I ground through the surface, the hollows became soft at the spine.
 
M

Mike Blue

Member
Exactly, above the hardening line toward the spine are pearlites and cementites that are softer than the edge. This is why the Japanese blades have such vibrant hamon. They only use low hardenability steels. Essentially this translates into "the least available manganese" in the billet.

Most steel mills these days are recycling so much of any metal that they can process that there has been a lot of manganese creep (upward). Practically that means never trust the mill when it comes to specific chemistry and you always have to do some test blades to know for sure what the correct times and temperatures are for what you just bought. The only way to control for that is to smelt your own.

It's nice to see that line wander a little. Most auto hardening blades the line will follow the exact section thickness where the transition between enough steel to quench versus enough steel to retain just enough heat to prevent hardening due to time occurs.
 
Bruno

Bruno

Administrator
Staff member
Mike today i etched your razor.

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Overall pretty happy. You can see the hamon still. Or rather you can see where pearlite touches martensite.

Time for scales. I think i recall vaguely something about mammoth ivory is that still correct?
 
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