Forging/Knife making - Getting stabby at home

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I forged out this sujihiki a few months ago from a wrench. It was originally supposed to be a tanto

Its the thing japs did for their swords

Ching chong ding dong weeaboo bullshit

 

[Skitarii]

Tried out some different quenching methods using a few batons I casted out of junk iron. Found an oil that preserved some neat microstrutures in the iron. I'm gonna test it again in two weeks to see if those were just impurities.

 

[Frostnipped Todger]

@Adolf Hulkler My steel finally arrived (after going all over the country for some fucking reason), and as you said, it is slightly warped. It's a 3.5mm x 32mm x 900mm billet, so the warp probably wouldn't be noticeable if it wasn't so long. Would I be better off trying to fix the warp after normalising, or get it straight, then normalise? I'm talking maybe 1mm over a 300mm length.

 

[Adolf Hulkler]

@Adolf Hulkler My steel finally arrived (after going all over the country for some fucking reason), and as you said, it is slightly warped. It's a 3.5mm x 32mm x 900mm billet, so the warp probably wouldn't be noticeable if it wasn't so long. Would I be better off trying to fix the warp after normalising, or get it straight, then normalise? I'm talking maybe 1mm over a 300mm length.

It will warp even more in quench.

Cut out a length of the metal you need, heat it throughout, straighten it, heat it up again, aircool.
If i deal with car springs i do it twice to save me from a headache later on.
If you normalize, and then straighten it when its soft, it will warp again.
You need to straighten it when its hot, then reheat it and let it cool down.

Never coldform metal if you want it to stay straight after quench.

I once had some railroad track spring plate(the U shaped piece that attaches to the railroad block and the track) and that stuff refused to stay straight no matter what, even after normalizing in hot ash.(takes hours to cool to room temperature).

 

[Frostnipped Todger]

straighten it

As I'm currently without an anvil (I'm just getting started, so my toolkit is limited), would you suggest sanding the blade flat, or clamping in a vise to straighten? I don't care about losing a little thickness (I'm probably going to make a small skinner to start), so sanding won't be an issue. Clamping seems like it would work, especially as the vise would slow the cooling process as well.

 

[Adolf Hulkler]

As I'm currently without an anvil (I'm just getting started, so my toolkit is limited), would you suggest sanding the blade flat, or clamping in a vise to straighten? I don't care about losing a little thickness (I'm probably going to make a small skinner to start), so sanding won't be an issue. Clamping seems like it would work, especially as the vise would slow the cooling process as well.

No, the moment you quench it it will still warp.
Ive straightened few hot pieces on a vice, but you need to make wooden jaws for it.
If you just use the vice as is to straighten a hot piece, youl actually quench it(the hot part between the jaws will rapidly lose heat into the jaws, this is an actual quenching technique, called aluminium block quench).
There are actual high temperature insulation jaw plans out there, i was going to make myself a pair UNTILL i read about how bad that insulation is for your lungs.(not asbestos, but ceramic aluminium silica fiber is still pretty bad)

You can straighten it without an anvil, its actually how i do minor corrections.
You need a dry hardwood block and a wooden hammer.
But in the end you still need to normalize the metal, because, again, the quench will bend it AGAIN even if you straightened it cold.

I watched videos of one american knife making company which also provided heat treating services including cryo heat treatment, and their common complaint(from the company) to the clients was that they should tell the company if they had normalized their steel before sending it over to the company.
Because when the client didnt say, and they quenched the blade, surprise, it came out warped.

 

[Frostnipped Todger]

Well, finally got all my bits together to build a mini forge. Three refractory bricks and a propane torch. I tested it out on an old file, and it looks like I'll need to move things around to get an even heat, but it's a start.
Tomorrow I'll cut some steel and get to work normalising.

Please excuse messy work bench... I was keen to test it out. Metal is an old file, will probably try to do something with it since the temper is now fucked.

I hope my images are thumbnailed. Fucking phone posters.

 

[wobinbobin]

I hope my images are thumbnailed. F***ing phone posters.

Yeah they are thumbnailed, nothing you need to worry about.

 

[Frostnipped Todger]

Hey @Adolf Hulkler , just wanted to ask a question; If I need to straighten my billet, should I do that before I start grinding bevels? Logically, it seems I should go: Normalise and straighten, shape and grinding bevels, normalise again (x2?), quench, temper, finishing.
Is this correct?

 

[Adolf Hulkler]

Hey @Adolf Hulkler , just wanted to ask a question; If I need to straighten my billet, should I do that before I start grinding bevels? Logically, it seems I should go: Normalise and straighten, shape and grinding bevels, normalise again (x2?), quench, temper, finishing.
Is this correct?

Depends what sort of tool you use to grind, if you use a belt sander, youl have difficulty grinding the concave side.
Also, before quench, dont grind in the bewels so that youre left with an "edge".
Leave just enough so you need to grind a little bit, then sharpen.
Ive had soft edges when quenching a "sharpened" blade, so you still need to grind away that "soft" spot.
If i recall its because theres juuuuuuuuuuuuust enough time for some of the carbon from the THINNEST part of the edge to burn away, leaving that small spot soft.

Grinding a flat piece is way better, but ive sometimes done "rough grinding" on bent car springs, with an angle grinder.
You dont need to really normalize when youre just straightening the blade.
Then again when i do that, i straighten and then drop the piece into a vat of dry ash to cool off, mostly because i have that vat of ash around.

You also dont need to worry about exceeding 250-300c while grinding the bewels in if your piece is unquenched, only bad thing that happens is that your grinders flap disk/belt sander paper will wear way quicker due to heat.
After youve quenched your blade be careful not to grind so hard/long that you start to see coloring on the steel.
I mostly avoid this by grinding free handed with bare hands on belt sander so i can feel the heat, my fingers burn before the metal becomes too hot.(also alot of water)

When i started, i only had one of these, for 100 bucks.

I still have it, and i do the finish on the edge with this tool to this day.
My large grinder has 80-120 grit paper, but the velcro discs on this thing go from 40 grit to 4000 grit.
I usually finish just to 800, then i polish to 4000.
The thing with the velcro disk is that it leaves a small "round" bewel, so the blade profile of the edge isnt straight.

I also have sharpening stones up to 6000 grit, i use those too.

Oh one tool you want to make yourself is a leather strop, just glue some leather on plywood and rub in some polishing/abrasive wax.

 

[Frostnipped Todger]

Thanks for your advise Uncle Adolf.
Perhaps I misunderstood, but previously when you said:

You can straighten it without an anvil, its actually how i do minor corrections.
You need a dry hardwood block and a wooden hammer.

I took that to mean that you heat to critical temperature, and then straighten. Are you doing this with cold steel instead?

As far as tools, I'll be filing in my bevels with this jig, which I'm sure you've seen variations of:

I know to leave 1.5mm or more on the edge for the quench, to avoid soft spots.
Again, I'm using 1084 so there's no soak timetable worry about.
I just picked up a 1x30" sander for cheap, so that will be in use, and I have a Tormek system at work for sharpening.

 

[Adolf Hulkler]

I took that to mean that you heat to critical temperature, and then straighten. Are you doing this with cold steel instead?

Always hot, i use wooden base and mallet because it doesnt leave any hammer marks.
And when i need to do minor corrections, im always at the "gonna quench" stage, so ive usually already put some sort of a flat finish on the blade with 240 grit, and dont want to remove the blackening(protects from rust)

 

[Frostnipped Todger]

Some further photos of my progress...

Normalised twice
And then..
Heat treated and quenched. I got it up to non-magnetic, and then quenched in warmed canola oil. I'll do the tempering tomorrow.
I've just copied a Benchmade skinner, but I plan on branching out with future builds.

 

[Adolf Hulkler]

>forge 246(- layers lost to scale) layer damascus billet
>grind it ready for quench
>cant see any delaminations
>quench
>spine splits length wise
FUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUCK

 

[Frostnipped Todger]

>forge 246(- layers lost to scale) layer damascus billet
>grind it ready for quench
>cant see any delaminations
>quench
>spine splits length wise
FUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUCK

That sounds like a nightmare. Did you get a photo, or were you too busy swearing?

 

[Adolf Hulkler]

That sounds like a nightmare. Did you get a photo, or were you too busy swearing?

i cut the billet in two, il try to reclaim as much material from this one and try to combine it with another failed damascus piece which refused to harden in oil, decided to do 4-5 seconds in oil, then water. Audible crack was the result.

 

[Not A Bunny]

I don't have much to contribute to this thread beyond saying I used to watch Forged in Fire and I have a knife I made at a local forge. I'm just jealous that I don't have the space or the energy to be able to forge like the folks in this thread, so I'll be following with fascination.

 

[Adolf Hulkler]

I don't have much to contribute to this thread beyond saying I used to watch Forged in Fire and I have a knife I made at a local forge. I'm just jealous that I don't have the space or the energy to be able to forge like the folks in this thread, so I'll be following with fascination.

Forget in fire is honestly the worst kind of "forging content" on video.
Its more about the suspense if a blade will break in a task that it isnt fucking intended for.
Few good channels on youtube are Alec Steele and Shurap.
Alec usually talks alot, and alot.
Shurap doesnt talk at all, he just shows the process.
Theres a few more but their names escape my mind at the moment.

 

[Skitarii]

Gonna be making my first axe head soon

 

[Frostnipped Todger]

Gonna be making my first axe head soon

Post progress photos if you can, I'd be really interested.