Bjorn makes sharp things. My beginners log book

[Bonnskij]

Haha! I might give that a go. I'd rather not end up with loads of toxic waste. Or maybe i can trade toxic waste for less toxic things, like a carton of beer. On that note though, could i simply force rust my spanners? (One of the lesser known Jedi tricks).

 

Also. Working on a file knife for a friend of mine. I've already normalised and thermocycled it five times. Yesterday i noticed the tang was a bit off centre, so i clamped the blade cold in the vise, and gave the tang a couple of wacks and it's straight now. But do i need to redo the normalising?

Also the hardening plan is clay the back and go three seconds in brine and then into canola. Good plan or rubbish plan? I'm trying  to get a hamon on this knife.

[Frosty]

The oldest of Jedi tricks is to turn less toxic carton of beer into more toxic waste. Which WILL force rust on unplated iron.

I admit up front I'm not a bladesmith guy but I watch Forged in Fire pretty regularly. In spite of that level of expertise I don't understand your plan. Clay the spine I get. Quench 3 seconds in brine then into canola?

I have to stop typing now.

Frosty The Lucky.

[Bonnskij]

Just got home from work, so i'm working on that one. I tried saving money by not buying beer for a while, but come payday i was just as broke anyway. Better to be broke with a carton of beer than without i reckon.

But if you'd ever try my homemade ginger beer I'd say you'd argue that got less toxic after processing.

Now i'm still very green, so apologies if i get facts and terminology wrong

I'm running on the assumption that the file is made of something akin to w2, so fairly low hardenability. 3 seconds in brine to quickly get it over the curve to convert as much as i can from from austenite to martensite. I believe the temperature needed to drop by a fair bit in just a second or so, but i cannot remember quite how much. 300 degrees Celsius rings a bell though.

After the initial fast brine quench I'll pop it into oil for a more controlled temperature drop for the rest of the way to reduce the risk of cracking.

According to what I've read the end of the quench causes more stress while a fast quench helps give a hamon more pop. It should be like a more controlled interrupted quench.

[Frosty]

Unless I misunderstood, you aren't making me want to try your ginger beer. I prefer to have things I drink come out less palatable. 

Unless one of the many top shelf bladesmith members here vouch for that quench sequence I'm calling BULL. It sounds like an urban myth invented by folks without the knowledge nor experience to "invent" anything but a myth.

This is exactly why we recommend new folks get off Youtube, buy a book and only watch vetted videos by known blacksmiths. Iforge's video library has been pretty mercilessly vetted by some high end smiths. 

The clay is what retards the quench speed retaining more flexibility in the spine. It's a differential hardening process.

The hamon is the result of hardened steel being more resistant to etchants so it comes out of the etch a lighter color than the less hard body of the blade.

I've never seen nor heard of doing a quench like that outside of a spring shop and they aren't developing hamons on spring stacks. The harden temper cycle I watched in the spring shop was nothing like what you describe above but used a water quench then a heat and oil quench cycle to temper.

Frosty The Lucky.

[ThomasPowers]

Re-normalizing the tang after bending it will help keep it from bending in the quench---*IFF* you are going to quench the tang.  If not then it shouldn't matter.

[JHCC]

7 hours ago, Bonnskij said:

3 seconds in brine to quickly get it over the curve to convert as much as i can from from austenite to martensite. I believe the temperature needed to drop by a fair bit in just a second or so, but i cannot remember quite how much. 300 degrees Celsius rings a bell though.

After the initial fast brine quench I'll pop it into oil for a more controlled temperature drop for the rest of the way to reduce the risk of cracking.

6 minutes ago, Frosty said:

Unless one of the many top shelf bladesmith members here vouch for that quench sequence I'm calling BULL.

Do NOT quote me on this or take it as definitive, but I've seen some things from respected knifemakers like Walter Sorrells and Kevin Cashen about using an interrupted quench in order to hit the TTT curve in very specific ways. HOWEVER, this is not simply a one-size-fits-all magic trick; they're using specific quenchants and specific quench intervals for specific steels in order to obtain specific effects.

 

 

[ThomasPowers]

I've seen more examples of oil over water in the quenchtanks to try to get "fussy" steels to quench without cracking.

Me; I invested in some Parks 50, an engineered fast quench oil!  I try to humour folks when they tell me their alchemy is all well and good...there are a number of Renaissance quenchants described in "Sources for the History of the Science of Steel".   (I will point out that medieval and renaissance steels tend to be quite shallow hardening!)

[Frosty]

I've seen interrupted quenches, and have a handle on how they work. Oil over water makes sense for a differential quench. I don't need to understand  the metallurgy to grasp the processes, even use them.  

Frosty The Lucky.

[Bonnskij]

Ah, see I don't use youtube all that much for anything but entertainment. As I said, I'm pretty green, but I've been in science for long enough to have a some critical sense of sources I should think. (Y'all need some Norwegiefied words for the record. "Kildekritikk" rolls much better off the tongue).

That being said. Metallurgy is certainly not my thing, and I find it confusing to no end. I like knifesteelnerds, this forum and bladesmithsforum. According to knifesteelnerds w2 (which my knife may or may not be) needs to cool in about three seconds.

Purely anecdotal, but a lot of the smiths on bladesmithsforum seem to swear by a water/brine into oil quench for good hamon with minimal risk of cracking.

Now for what I have seen on youtube. Blades don't appear to crack until several seconds into a water quench if they do. This too makes sense to me, as I would imagine the whole blade is hot enough at the start of the quench to bend rather than crack under the stresses. When the edge is fully cooled and hardened and the thicker spine then cools slower after and contracts, it pulls apart and breaks the brittle edge.

As for the oil. I am assuming if I mess up an interrupted quench, the retained heat in the blade will simply autotemper the knife, and quite possibly overtemper it. Oil should cool it quickly enough to stop that from happening.

I have seen some of the old recipes for quenchants. Are you trying to tell me the urine of a redhead is not the ultimate of quenching liquids?

Would oil over water be a thin layer of oil floating on top of water and then the spine is left in the oil while the edge is in water during quenching?

As for my ginger beer. It is a combination of seriously tasty and a donkey kick in the jaw. About half a glass is enough to put you on your behind and give you a cracking headache in the morning. "Old death whisper" seems to be as fitting a name for it as the whisky in fup duck. Tastes alright though.

 

Hope I didn't miss the point entirely or it's looking like I'm trying to start an argument. Just want to understand the processes and how to best make the things I enjoy making.

[Bonnskij]

ActualIy I guess my comment on youtube isn't entirely correct. Thorbjorn Ahman is a great inspiration, whatever Walter Sorrels says on his videos hasn't steered me wrong so far as i know and I'm looking forward to trying out some of the stuff I saw on a few Brian Brazeal videos lately.

[ThomasPowers]

Urine Quench; proposed by Theophilus in "Divers Arts" written around 1120 AD; I've used it, (exhaust bath of a traditional indigo dye vat. Stale urine has such an amusing smell when hot steel hits it.)  It works as a rather weak brine quench, as does fresh blood BTW, (pain to clean the blade off for tempering though.)

Worm water and radish juice are two I remember from "SftHotSoS".   Most quenches still default to being like: brine, water, oil and air.  Many of the old ones tend to have "Magic Feather" ingredients. They were also used for shallow hardening early steels and can be too abrupt for many modern steels.

 

[M.J.Lampert]

2 hours ago, ThomasPowers said:

as does fresh blood BTW,

"probably" illegal now but IIRC i read that it the middle ages some blades where quenched by putting a red hot blade through the heart of a prisoner or a slave who no longer serves a purpose to its master. not 100% certain of it butt makes some cents for a blood quench as fresh is required. nowadays one would maybe do a pig if necessary?

M.J.Lampert

[JHCC]

That's utter nonsense. It's certainly true that branding was used as a punishment up until comparatively recently (e.g., the two British soldiers convicted of manslaughter in the 1770 Boston Massacre were branded on their thumbs). However, there are a number of factors that would bear on this:

1. The entire blade needs to be quenched quickly and evenly. Stabbing someone in the heart doesn't cover the entire blade, and the different materials within the chest cavity would quench at different rates.
2. A blade needs to have considerable strength to be thrust through the chest. A blade heated to critical temperature (about 1335°F / 724°C) is much more likely to bend from the force of the thrust than to make it through the chest wall (both front and back) and to be withdrawn.
3. Generally speaking, enslaved people always had a purpose to their enslavers, even if it was simple manual labor like teasing apart fiber, helping in the kitchen, or the like. 
4. It's simply impractical. Why go to all the bother and expense of using a human as an imperfect single-use quenchant when water, urine, and brine were all ready to hand for practically nothing?

This is more the stuff of fantasy literature than actual history. 

However, we do encourage experimentation, so if you want to try stabbing a pig, go right ahead. Just a couple of things: first, even if you're successful, the process would probably be terrifying and painful for the pig. The only humane option then would be to stab its carcass immediately after slaughter. Second, documentation, or it didn't happen. Finally, be prepared to face significant ridicule if you fail (like the guy in Hawaii who tried to harden a sword by sticking it in a lava flow and then pouring the contents of his water bottle over the resulting red-hot steel noodle).

[ThomasPowers]

Actually that is pretty much an Urban Legend; I dug into it a while back and found that people would claim that their enemies would quench blades in people; but *they* wouldn't do that. One time I even found a complete circle where each ground would claim that a different group would do that but not them and I tracked it around till it hit the first group again!

If you have ever worked with a sword blade at high temp it's just one step less flexible than cooked spaghetti and so a quench medium with hard spots and differing densities/fluid contents would almost guarantee a useless blade due to bends and warps!   Now blood fresh enough to still be liquid and not coagulated will work; but for a very short while before it clots.

[Bonnskij]

Well my heat treat seemed to work out alright. Never seem to be able to photograph hamons properly, but here's a preliminary etch. Now I'll have to figure out how to add the secondary bevel in a reasonable timeframe without scratching the blade

No humans or other mammals were harmed during the quench. I stuck with the brine and oil.

[Bonnskij]

Finished a couple more bottle openers this morning. Tried Brian Brazeals  method for drawing out a taper. Not used to it, so drew out a lot longer than normal and had to do the head end differently to what I normally do. No mistakes. Only happy little accidents.

 

I also quenched this little guy:

Unfortunately my welds weren't up to par and it delaminated. 

[ThomasPowers]

What alloys and how did you quench it? (Temp, quenchant).

[Frosty]

It's pretty normal to draw tapers too long until you've used Brian's technique a while. It's my main go to method now.

Frosty The Lucky.

[JHCC]

One really useful thing to keep in mind is that tapering a square bar in one dimension (that is, to a chisel edge) will double its length, while tapering in two dimensions (to a point) will triple its length. This is true regardless of what tapering method you use. 

For example, if you want a six-inch flat taper, start tapering three inches back from the end, and if you want a six-inch pointed taper, start two inches from the end.

[Frosty]

And rounding a taper will add about 75%.

Frosty The Lucky.

[Bonnskij]

21 hours ago, ThomasPowers said:

What alloys and how did you quench it? (Temp, quenchant).

1084 core with a mild steel jacket. Heated to one shade brighter than non magnetic and quenched in pre heated canola oil. 

I suspected parts of the weld hadn't taken when I filed the bevels and I saw a hairline run along the middle, but thought I'd try quenching anyway. I'll know for next time now to do more welding heats Maybe I can grind down one side and make it a left handed tiny knife.

Thanks for the input on the tapering Frosty and JHCC. I like this new method of tapering, though I'm ending up having to do more clean-up as well so far. That's just something else to work on for me. Worth not having to deal with all the fishmouthing. 

[Bonnskij]

New addition to the kitchen coming along. This concludes the hand sanding, so I'm on to the handle.

[Bonnskij]

Second krumkniv together with the first one:

[Bonnskij]

[Rojo Pedro]

I like it. Is that a piece of the starting stock?  What size