Prep Work Prior to Heat Treating Tips And Tricks

I just received 3 4ft flat stock of the 8670. I am gonna give it a go this weekend and make 2 or 3 shorter blades from it
 
Make the new blades one at a time. You will learn much more that way.

It is also good to post sketches or draw the proposed blade on the steel and post a photo before grinding.
Old oriental proverb, "Many eyes see what one eye may not see."
 
I agree with Stacey that 1560-1630 is too high, I think 1525 is a good number to shoot for if your heat treating in a forged/torch starting out it’s easy to overheat so what I would do when your ready to heat treat is cut off a few samples about 2” long and quench them at a couple different temperatures. Bring one sample up to non magnetic and immediately quench (this should not properly harden the piece but it gives you a example of how the steel will be under temp) the second sample bring it a full shade of color past non magnetic and quench it (chances are this will be your target to shoot for in the future) on the last sample go 2 full shades brighter than non magnetic and quench (this is your example of overheating a blade) don’t temper any of the samples, put them in a vise and snap them in half and compare the grain of the steel the middle sample should be fully hardened and have a very fine grain, the first sample may look like a fine grain but it won’t be fully hardened and may even be hard to get to snap it might want to just bend and the last sample should have a more coarse looking grain. It’s important if using a forge or torch to work in a low light as possible so you can get used to reading colors.
 
I just looked it up. Larrin says 1525°F and 10 minute soak. 400°F temper.

If you are using a forge, that is a full shade brighter red than non-magnetic. Not orange-red, but considerably brighter than when it lost magnetism. Without the ability to hold for at any one temperature long in most forges, just get it evenly colored as well as possible, keep it moving, hold for at least one minute ( that will seem like 10, trust me), and quench in 130° canola or in Parks #50. When heating the blade the important part to watch is the edge and tip. These heat much faster than the rest of the blade ... and the edge is the most important part that matters in the quench.
 
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Great advice, all of you. Thank you. I am going to get started tomorrow. Here are some of the templates I drew up. Thoughts?SmartSelect_20210123-160906_Gallery.jpg
 
I'll be honest. You need to start over on those. The blades are more or less OK, but the handles are really bad. Look a 30-40 photos of good knives and study the handles. Then re-draw them and see what people think.
 
Beware working with batches to begin with. I think it is better to finish a whole knife and use it, before starting on the next one. That way each knife can improve on the last, rather than having several all going at the same time, with the same ....lets call them sub-optimal features ;)) There are things that could be mistakes and its better to do them once, see the effect, and not repeat.

I agree with Stacy that it would help to look at pictures of good knives.

Some of the blade shapes are better than others, but the handles could all do with some rethinking.
  • Finger grooves are generally not a good idea, very hard to do well.
  • Sharp corners at the butt end are generally bad. Acute sharp corners are worse.
  • Deeply dropped edges can generate more torque that needs to be reacted by the hand on the handle, handles that are skinny back to belly don't give much to hold on to.
  • Starting with a handle length of 4.5 to 4.75" is a good beginning. 4" is a bit short, if anyone holds in a saber grip the heel of their hand will tend to hang off the butt.
  • The fairly extreme curve down at the butt looks problematic, but its hard to describe in words what to change. Straighter handles tend to be more versatile on small knives
I would suggest looking at production knives, high grade "tool" knives that are made to standard patterns or in quantity, rather than at one-offs. There are a couple of reasons I say this. The design of knives that are made in quantity tend to to have been through a more rigorous design process and they get refined over time. They also give a better chance to see a range of similar knives with similar aims. You can start to see common features, things that are deemed to work on all the knives across styles, or you can compare from one make to another. The work of solo craftsmen can be more varied, its harder to identify patterns and it can be hard to know if a particular knife really worked, or whether it is more style driven. Not every knife is a home run, but it can look great and be shared because it looks beautiful. Doesn't mean you want to copy it for a tool.

If I were looking for inspiration I would look at these.

Small, deep bladed hunting knife examples
https://www.benchmade.com/15006-steep-country.html
https://www.benchmade.com/hidden-canyon-hunter-family-hunt.html

https://www.bladeforums.com/threads/finished-custom-orders.1466873/
https://www.bladeforums.com/threads/photos-post-your-cpk-photos-here.1404389/
https://www.bladeforums.com/threads/fiddleback-user-pics.612052/page-228

https://www.lionsteel.it/n/en/allproducts/_/fixed_blade?ffa_157=1

This one might be closer to your taste than mine.
https://www.bladeforums.com/threads/picture-thread.1289356/

Best of luck!

Chris
 
I have a slightly different view of working in batches, maybe because I can only get relatively short stretches of shop time. Once you are set up for a task, it does not take so much more time to do two or three, so I always make two or three blanks and take them through HT. As a beginner, having to start from scratch when making a mistake grinding would be frustrating to me, especially since I mostly use AEB-L and grind post HT. It is really nice to have that second and third heat treated blank ready to go, and I had to use the backup blades on the first few knives I made.

My daughter got a new video game recently and every time you die, it immediately throws you back to the first level. That sounds incredibly frustrating to me, but she likes it and she is really good at playing the first few levels now... In the knife making game, I prefer to start out with a few extra lives, so to speak.
 
When you are new the reason to make in singles is you only make the same error once. On the next you make an improvement. By the time several have been made, you have progressed a lot.
If you make three, or ten, knives wrong, what have you learned.

Once you have them all ground out and ready fro HT, then working them as a batch makes sense. In finishing, go back to one at a time again.
 
Will do. So I need to re-consider length of the handle at the very least, and also think about the best way a handle allows the user to control the blade. Making sure there is ample room for all fingers
 
I agree on making the knives one by one, and that is what I still do (mostly). I just like to have multiple blanks of the same design profiled and heat treated before grinding the bevels. When I started, I knew I would not be able to grind a bevel on a kitchen knife that I would be happy with on the first try. That's why I always profiled and heat treated multiple identical copies before starting on the bevels. The additional cost in time investment and steel is pretty minor in the greater scheme of things, but the cost in time and frustration to start over from scratch if you mess up the bevels is pretty high. Obviously, that equation is a bit different if you grind before HT, but there is still efficiency to be gained. Even though I am much more confident now, the batch of knives I am getting ready to heat treat has two or more copies of every design just in case. If everything goes well, I'll have some presents to give away.
 
The situation that comes to mind, regarding profiling and heat treating multiples, is if you drill holes for pins/bolts, ensuring they are a really nice fit...then heat treat, and all the holes shrink. Now you have however many holes x multiple blades and the fun job of opening holes in hard steel, or down-sizing the fixings.

If you make hidden tangs, I think there is a lot less risk in taking several blades to a heat treated stage. You have not tied yourself to a handle shape.

Hubert S,
I certainly do hear you with your video game analogy. Maybe my different perspective comes from having made my first 12 or so knives without the benefit of power grinding or power cutting. It is much harder to "die" and be thrown back to first level when you are hand filing and hand sharpening on a stone. I timed making one of those early knives (morticed tang, wood handle, 6" blade in O-1 with brass double guard) and I spent every spare moment, and let all domestic chores go hang, for two weeks. That sort of time investment per knife increases the risk of making multiples when you are starting out with the designs. Three of the earliest were heat treated by someone else, as a batch, and I made the same mistakes on all three, which meant that after completely finishing them they went in a box never to be used.

My last batch (14 assorted), made with the benefit of power, presented another situation, by the time I had finished a few of them, my ideas about the ideal design had changed. Finishing the rest means performing remedial corrections rather than just finishing as originally intended.
 
One tip for drawing the knifes to make the scaling easier is, draw your stock size on a piece of paper, mark you overall target length, mark your handle, blade, ricasso (if you have any or just leave a 1/4" for handle to blade transition area) and middle point. Mark the width of your blade at the heel. Draw a straight reference line for the blade toward the tip. From the middle point of the spine do a gentle drop line towards the tip and towards the handle but. Establish your handle width at the widest point. Now fill in the rest and adjust the line. Keep the lines on the blade gentle and the radius on the ends of the handle small. In small increments adjust the lines as they please you. Here is a very simple design of my ideas, ignore the knife. Its just how I do it, so others might have more or better ideas, this is quite basic as I am a newbie myself.

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Also a set of French curves will be helpful.
They make nice eye pleasing curves that will really help your designs look polished.

At least in my opinion...
 
SmartSelect_20210125-215522_Gallery.jpg Ok. Round #2. If these aren't any good at all. I am quitting. NAH!!!!!! just kidding. I do really want to know everyone's thoughts though.
 
The handles all look a bit off to me, especially the butt ends and the finger grooves. You could try something without grooves altogether, maybe like in the attached sketch. I helped a colleague make a skinning knife similar to that and he has used it on a couple of deer and seems to like it. Not sure if that's because he made it or because it really works well, but at least he says it does. It felt good in the hand to me, and the jerky he brought in tasted pretty good, too.

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No 4 and 5 are closest to it imho, try to do a gentle curve on all the back, your spines are straight and then you just drop the handle and tip and that looks off. Handle buts will look and perform better angled up, like in no #4 (edit: no 3). Keep at it! Maybe just one design and one size EDC and do more variations of it.
 
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