Thread: 1st attempt making a razor

Congrats!, The razor looks very good.

Just a couple of comments.....

Remember to "Normalize" the blade 2-3 times before the Heat Treat. Mike Blue said that will not only relieve stresses in the steel thus reducing the chance of the blade warping but also refine the grain size.

Forge.... I agree with Spazola, a tangential angle would get the flame to swirl around the muffle which will speed up the heating cycle. I also agree that you may not have enough space between the muffle and the wall of the forge but go ahead and try it as is first. Remember that a muffle is not necessary, just run the flame a bit rich so that it is not oxidizing the steel as much. I assume that you have extra thickness along the edge and extra width on the blade to compensate for carbon loss. If not then be sure to use the muffle with some bits of leather in it to burn off the oxygen (but you probably already know this).

Vertical forge and wire.... just use a 1/8" to 1/4" steel rod laid across the mouth of the forge. That should be more than adequate to hang the blade onto. What kind of wire to use I am not sure, maybe SS?

Spine work....may I suggest that you fully finish off both the spine and the tang before HT. They are a bear to do after HT.

Hope this helps,

Thanks Randy for HT advice and kind comments.
You pretty much describe and confirm the process as I've go it in my head regarding normalising, though I didn't think to hang the blade and that's a good idea.
The muffle was primarily an idea to disipate and even out the heat for this type of oven, but thanks for the leather tip in the pipe.
Regarding decarb, I can run a fuel rich flame if tube dosn't work out, plan b is to remove tube, tube is 2" cavity is 3"? Was wondering if I could use a refactory wash to paint on the blade to minimise decarb though I do have about 0.030" left on edge.
Spine and tang work is there, my photography is rubbish. I have something in my hand that looks like a mirror but has the texture of a turd on the screen, think I'll make a light box to photograph the finished product.

Thanks Randy for HT advice and kind comments.
You pretty much describe and confirm the process as I've go it in my head regarding normalising, though I didn't think to hang the blade and that's a good idea.
The muffle was primarily an idea to disipate and even out the heat for this type of oven, but thanks for the leather tip in the pipe. Ahhhh... the ever elusive goal of obtaining a uniform temp before quenching from a gas forge...yes it can be done but only by gradually increasing the amount of gas entering the forge ( a time consuming PITA). But... it really is not necessary. My focus is only on the bottom 1/3-1/2 of the blade, that's what I shave with and if you could check the HRC of some vintage blades I think you will find that the spine is softer than the blade edge. You will have to experiment with positioning the blade in the forge to adjust what gets hot first.
Regarding decarb, I can run a fuel rich flame if tube dosn't work out, plan b is to remove tube, tube is 2" cavity is 3"? 2"- 3" is more than adequate. Was wondering if I could use a refactory wash to paint on the blade to minimise decarb though I do have about 0.030" left on edge. I have tried using a few different compounds to protect the filework on the spine. Sometimes it can be a pain to remove after quenching. Your best bet is to first do some trial runs.
If the thickness of the edge is 0.03 then you can bet you will lose about 1/16-1/8", probably 1/8" in the width of the blade. Sorry.
Spine and tang work is there, my photography is rubbish. I have something in my hand that looks like a mirror but has the texture of a turd on the screen, think I'll make a light box to photograph the finished product.

I

I thought your filework finish was just fine. I just wanted to reiterate the reason for doing so in case the pic was fooling me and for the benefit of others who may be trying this.

Thanks for feedback.
The 1/8" loss is a shame, but the blade is quite wide so should be able to reduce width to recover this and still end up with about 6/8 width in real terms.
I read somewhere we don't make mistakes, just smaller bades?

OK,
Heat treatment done, had a small time window as my young son was off the scene, I had to do this in my yard.
Forge worked great, got a good swirl around pipe and fired it verticaly as advised previously and used large paper clip to hang razor. Quenched in canola heated to 120 F, couldn't obtain an industrial quenchant in small amounts (need to get in the know on various forums).
Had no chance of gauging by eye for coulour/shadows in this type of oven, so after 3 normalising cycles tested for non magenetic every 30 seconds plus an extra 30 seconds before quench.
Happy with result, no warping that I can tell and scaling was minimal.
I lost about 1/16" at most on width, tempered at 400F for an hour.
Rockwell tested piece at work near edge and got readings of 52/53C??Don't know how this relates but I can put a nasty dent in a brass rod without marking the edge, file also skates where I've sanded away some of the surface steel, only time will tell if it will hold an edge.
I want to do everything myself for this blade even if I screw up, I'm just like that. Due to limited time I didn't photograph the process but if anyone would like I can post pictures of set up (let me know).
Final hurdle, final grind????
Thanks so far to everyone who has contributed advice and pm's (you know who you are).

Joe

Rockwell 52-53 is fairly soft, but I'll bet it'll still take an edge and shave. Softer steels feel Sheffield-y. Also, it's pretty easy to end up with a soft decarburized skin, so you might have a harder blade once you get past that.

The file test is useful to some extent, but it doesn't tell you much. Very soft steels (Rockwell 30s) can skate a file under the right conditions. With some steels you can get pockets of very hard cementite in a soft ferrite (pure iron) matrix. The file will hit the hard stuff and skate, but a Rockwell tester pushes the hard pieces of cementite aside. Think of it like a slushy mixture of crushed ice and water.

Color is not a very useful indicator of temperature, unless you do your heat treatments in the exact same lighting conditions every time, and you have a photographic memory. Although it's safe to say that bright yellow is bad, especially if it's giving off sparks.

What steel were you using again?

For good quenching oils in small quantities, try http://elliscustomknifeworks.com/. Darren's got 1-gal. quantities of Parks 50 and AAA. You want 50 for fast steels (10XX, W1, W2) and AAA for O1.

Looking good!

Josh

Thanks Josh.
Steel is 1084 equivalent don't know exact spec but can find out, we generally don't tend to use 10XX steels in the UK but back of the stock packet shows composition close to 1084.
Rockwell machine in our toolroom is a nail to say the least and not properly set up even on a calibration 63C test piece I found repeatability problems. The readings I obtained were an average of 3 readings trying to keep the blade flat on a magnetic block and a little guess work.
I'm having fun and learning stuff here.

OK, a 1084 equivalent probably won't have the structure I was describing--that's more typical with 1095 or other steels where the carbon content is over ~.8%. You probably just missed the ideal temperature by a little--my guess would be that you overshot. It's really hard not to do, and 150 degrees F can make a big difference. It happens very fast, especially at the edge. You have to get the temperature to drop in a 1084 blade from about 1400 F to under 900 F in just a little over one second. If you overshoot and your blade is 1550 F, that's another 150 degrees that the oil has to absorb in that same timeframe.

Regardless, it sounds like a successful first effort. My first attempts didn't go as well.

Josh

Thats your first attempt? Wow, well done! That's much better than my first 6!
Don't sweat the HRC. You will find out if it needs a higher tempering temp when you start honing it.

Joe,

That's a good looking razor.

With the relatively low Rockwell numbers, I'm wondering if you still have decarburization on the blade where you were testing it. Decarb's pretty hard to avoid unless you are using molten salts or coating the blade. If you are doing further grinding, it would be interesting to see what the Rockwell number is after it's all done. (There's a brief explanation of Decarburization in the second paragraph of this post about Forging.)

If decarb turns out to be the culprit, you could try coating your blades with Satanite or Anti-Scale Coating. Here in the US, Knife & Gun Finishing Supplies carries the Satanite, and Brownell's sells the Anti-Scale coating. (I'm sure others do too.) I don't know if you can get equivalents in the UK.

If I read your post correctly, you only tempered your blade once. Normally, you would temper a blade at least twice. You can temper at successively higher temps to reduce hardness, but you can't increase hardness by tempering at lower temps on successive heats. With Rockwells in the low 50's, you wouldn't want to lose any hardness, so I would use the 400 F degree temp again.