Did I completely screw the pooch on this?

O

Omega Leather Works

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Jun 13, 2007
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After doing a bunch of cleanup sanding I realized two things about this blade.

1. It's extremely thin at the edge (my calipers won't measure it, just shy of a sharpened zero grind)

2. The tip is extremely fine in every way.

:(

8EnTNX3.jpg


It's 1084, 1" height by about 1/8" spine ffg.

*If* it survives ht it's gonna be delicate.

Should I just drill the handle holes and try the ht, or put it in a drawer until I've had more experience ht'ing? Put way too much work into this to just toss it. I would have to bring the edge/ricosso/palm swell up at least 1/8" to get .02" at the edge, too drastic imo.

Bleh...
 
Measure how far up into the hollow grind you have to go before it's as thick as you think it should be then scribe along the length from front to back at that distance and see what the new slightly smaller blade looks like, then make your decision.
 
Simple fix. Gently run the edge against a high grit belt in line with the belt. You'd be surprised how little it takes to get back to 0.02" or so. If you need to, a slight reprofile of the tip will get it more solid (again, in line with the belt not perpendicular to it).

--nathan
 
I probably didn't explain that well... I already figured out that I'd have to grind the whole bottom of the knife (edge, ricosso and handle) up at least 1/8" to get the edge to .02" I don't want to do that since overall height is actually just under an inch.

The edge is just shy of sharp. I haven't looked at what the bevel angle is, should I decide to go zero edge. It's gotta be nearing straight razor territory, or well under 20° inclusive as it sits.

I had an appropriate edge scribed for grinding. Inexperience got me when I ground to the lines with a 60 grit belt. In finish sanding it got me to where I am now.

It's full flat ground btw. And yes, I am very concerned about the tip. It's very very thin. To give it any chance I'll have to temper back to a hardness that I won't like anyway. That or just use it very carefully which would make a higher hardness with good edge retention pointless. Sorry, just thinking out loud.

May have to just shave with this one and chalk it up to experience. :D

One question. I'd like to use a muffler in my 2bf to try and save that tip. What would be the best for the job? Knowing that the forge is so small, would something like a stainless pipe with an i.d. of 1.5" work? Do I use a solid piece or cut slots in it? Also, edge up (off the pipe), or does that matter? I understand the concept, but have never used one.

A lotta firsts for me with this blade.

Thanks for any advice!!
 
Why don't you want to grind the blade and whole ricasso vertically on the platen like mentioned above? You said yourself that this ones bound for the drawer. I think i'd rather finish a knife than not. Reworking mistakes is what this is all about man. Your little blade that's not as wide as you hoped may also be alot cooler than you expected.
 
Maybe you guys are right. I'm working on a short/tiny platen on the 1x30, but I could easily sand it down by hand, or use the 4x36.

I guess that would solve most of the issues.

I guess I was hoping for a "ah, it'll be fine" response, but I know that it very well might not be. I also kinda just want to be done with this one and move onto the next, but that achieves nothing.

Thanks guys. Guess I'll shorten it.
 
I am in a similar boat, I am just about finished pre-HT hand sanding a knife and am worried about the tip. I traced a forgecraft hi-carbon butcher (my favorite kitchen knife) onto paper and shortened the length. not only did I screw up the plunges but the tip is like a needle. I decided to go ahead and HT in my paint can forge and just give it to a buddy of mine to test for a while and then break it and check the grain. I plan on finishing it just like I would any other knife with the exception of probably using cheap white pine for a handle. but Im still going to get every ounce of experience out of it that I can. I dont expect much out of it but who knows I may be pleasantly surprised.

Aldos 1/8 1084 btw
 
If you are thinking that it is bound for the home pile why not try to ht it anyways? Think of how thin some slip joints are when going through hardening. You will chalk it up to learning no matter what! ;)
 
Ah, sure, go ahead you'll be fine! ;)

I have had .010-.015 1095 survive a water quench. And have seen some remarkably thin stuff that was stronger than I ever would have thought.

For a muffle/baffle, I use a 'tent' rather than a pipe. The tent is just 16ga stainless and I can sit a blade spine down under it. No holes. As the baffle heats so does the area under it, only more uniformly than the direct flame. I don't know how your heat control is, but maybe go for a differential HT watching the edge closely and grabbing it right at the moment your edge is at temp? The quench time for 1084 is longish and the cross section is thin. Warm oil, right at temp with the edge, maybe 1/2" deep into the blade? It could survive... Make sure its ultra clean and that tip is gonna get hot in a hurry... Draw it back a little further with the tempering regimen than usual to spare a brittle tip. Zero grind it... done! I mean better to die tryin than never tried at all right?

Take a black background, lay the blade on it and then use a piece of black paper trimmed to mock what you would grind back to. If that looks pleasing, do that. If not, give the HT a shot. I saw your pic of that one on the grinder thread. Looks like a cool blade...

I have faith!

-Eric
 
Good idea on the paper thing. Why didn't I think of that?

My temp control is my eyeballs, but every ht I've done so far has been successful. At least so far as I can tell.

Good point (get it?) about the slippie blades. I do have a few carbon blades that have tips easily as fine. ( ;) )

Okay, I'll figure this out and let you know how it turns out. :)
 
Is that Aldo's 1084 in .156 x 1.00 ?
If so , then I can say that some of my luckiest Heat Treating days have been with this steel .
Lately I have been fearlessly grinding some pretty feathery looking blades .
I've even taken the risk and Water quenched some of the thinnest ones .
So ,as an amateur ,I say Quench it .
If it warps you can re-shape after H.T.
But I'm betting it wont warp.
 
LucyCustomKnives said:
Its a cool design, I've got my fingers crossed for you.
Click to expand...

Thanks man, I've got mine crossed too. Did a paper cut out. Just doesn't look right to me. A 1" handle height is already kinda small for my big mitts. I have another knife with a similar handle shape. I did the scales in a coke bottle shape and I like it a lot in terms of looks, but it's small and feels like it puts my hand forward a bit too much. Always makes me feel like my thumb should be on the spine. The whole knife is a matter of fitting inside the steel stock. Not the best way to do things, but it is what it is.

eric brinkerhoff said:
Is that Aldo's 1084 in .156 x 1.00 ?
If so , then I can say that some of my luckiest Heat Treating days have been with this steel .
Lately I have been fearlessly grinding some pretty feathery looking blades .
I've even taken the risk and Water quenched some of the thinnest ones .
So ,as an amateur ,I say Quench it .
If it warps you can re-shape after H.T.
But I'm betting it wont warp.
Click to expand...

Yeah, it's exactly that. Glad to hear you've had good success with it.

Was there a reason why you water quenched? I know that works well (if it doesn't crack) on 1095 and W1, 2, etc, but I don't think I've heard of doing 1084 with water. Interesting. :)
 
Finally had a chance to heat treat it last night. The tip is ever so slightly off center. I think I can fix it by heating it clamped and quenching in water. Very happy about this. :)

One, possibly big, problem...

I clay coated this blade in the hopes of getting more experience with the hamon process.

After tempering twice at 430° for two hours I sanded it a little to get the clay off that didn't fall off in the quench.

There is a very obvious line down the blade. I need to know if this is a quench line. If it were higher I'd continue as planned. However, the line is unexpectedly low. The clay was much higher before HT, so if it is a quench line, why did it happen this way? The short hardened area (if that's what it is) will compromise the life of the blade since it would eventually be consumed from repeated sharpening. Still, that would take an awful lot of sharpening. I'd likely call it timed served before I ever got there.

My next question... Is there any kind of qualities of the blade that would be negatively impacted by such a short hardened area?

If everything is a go, and that is in fact the quench line I won't polish it out because it looks weird to me.

Any help is greatly appreciated.

Here's where it stands.

syRjPIw.jpg
 
How much finishing have you done post HT? Sometimes, there is a line where the quench oil stickies up from flash boiling. Won't be the same as the quench line per se. Without getting to the steel and etching would be hard to tell if that really is a quench line or just leftover goop.

I'm glad for you that it isn't pooched.
 
I just quickly hit it with 120 grit paper. When I came across that line I stopped in case it needs to be re-heat treated. I've now gone over the entire blade (it's still rough) and the line has mostly been ground off.

What really gave me pause was that the dashi that I did a little while back had a hamon lower than where I had the clay. One major difference was that there wasn't a post quench line like this one. The line only came about when I etched it.

I'm probably going to sand it to 400 or so, then etch it to see what happens. I'm hoping the line rises, but it won't be the end of the world if I have to re-ht. The reason I don't want to is because it gives the blade another chance to develop a more pronounced bend.

Btw, the slight curve seemed to happen in the forge, not in the quench. I'm not sure if that's normal, but there you have it. :)
 
I discovered a while back FeCl can give you a quick litmus test of the boundary in a differential HT. Simple carbon steel will blacken with FeCl, pearlite won't. Swipe across the bare steel and see.
 
Honestly I like it. You might have to alter your intended use for the knife but it will be a hell of a slicer. I personally love thin blades. Almost all of my work knives I sharpen to a zero grind.
 
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