Need help with a knife idea - WIP thread

Hey, bummer your knife broke!

Here's something to think about too, when using recycled steel. That steel was taken out of service for a reason. That crack could have been there when you started forging, maybe as a micro-fracture that you couldn't see.

Then as you forged the blade that crack propagated to the point that when you tapped it, it gave up the ghost.

Of course there's no way to prove where it went wrong but at least you got some forging practice out of it!!
 
I agree AJ. The beaut big failed. That’s the reason it was taken off the plow. That thought already crossed my mind, but like you said, there’s no way to know for certain. I can’t help but think my inexperience was a large cause of that.

Drew, just so I’m clear, normalizing will reduce the grain, correct?
 
Micro-cracks and other issues with salvaged steel are always something to be cautious about. In this case the fault was massive grain growth. I have never seen grain size that large in a blade unless it was deliberately done to show what it looks like. I can't imagine how much overheating and multiple heats that blade had to get that bad.
 
Blackdirt cowboy said:
This morning, while grinding, I kept it cool by dipping it in a bucket of water. It never got so hot that it was uncomfortable holding it bare handed.
Click to expand...
That blade was not HT so you don t need to worry about heat .After you quench it and temper it ,be careful to not overheat it :thumbsup:
 
Stacy E. Apelt - Bladesmith said:
Micro-cracks and other issues with salvaged steel are always something to be cautious about. In this case the fault was massive grain growth. I have never seen grain size that large in a blade unless it was deliberately done to show what it looks like. I can't imagine how much overheating and multiple heats that blade had to get that bad.
Click to expand...
Well, it was my first ever attempt at forging, so I’m positive I did something wrong. I’ll keep trying. I really don’t think I over heated it. It never even got anywhere near welding temperature. I did have to put it in the fire quite a few times to forge it out. Maybe that was my issue.
 
Blackdirt cowboy said:
Drew, just so I’m clear, normalizing will reduce the grain, correct?
Click to expand...

Yes, you would normalize to reduce grain growth. That said, don't mistake it for a cure all for severely damaged or overheated steel, or steel that's been cracked or fractured for whatever reason.
Natlek posted a good picture above of some examples of the change in grain you should see after x number of normalization cycles. Try a couple of cycles on one of your blade halves and break it again to see what it looks like. Then compare to the other half.
 
Alright, I decided to scrap the idea of working with mystery steel plow bearings. I found a piece of 1/8” x 1 1/2” 1084. I forged it into a knife today and it worked so much easier than the plow bearing. I was even able to forge most of the bevels into the blade. I was pretty excited about that. I’m not really digging that funny dip in the spine where the handle meets the blade. I can’t figure out how to smooth that up other than with a grinder. I not finished with it yet, I was called away from the project. I need to heat it back up and clean it all up a bit. Then I’ll normalize it probably three times, then anneal it so I can grind it and drill the holes.
I know it’s probably not edc size, but it’s what I had and what it made. I’m sure my son will be excited regardless. Let me know what you think or if you have any suggestions.

5FVhfnr.jpg


ZBvDRrj.jpg
 
I have only forged a handful of blades myself, but I think you did a good job on the bevels! thats where I always have some issues.
 
Got my belt sander in and set up last night. Here’s the knife after 60 grit. I think I’m going to some more refining on the handle. It looks too big for the blade. Let me know what you think.

Gu4YG4S.jpg


AzNc1xv.jpg
 
overall it looks great! whats the current length? I find that handle shape is pretty subjective, but since this is for your son you could just ask for input from him.
just remember this is an amazing blade for a first time forge work! your first is forged to the quality of my tenth!
 
Blade length is 3.25” and handle length is 4”. My son said it fits his hand perfectly, so I guess I’ll leave it. How high of a grit should I go to before heat treating it?
 
Well, this WIP is turning into a work in failure. I heat treated the blade today and it came out with a little bit of a warp. I went to clamp it in the vice to straighten it as it cooled, and it snapped. To my untrained eye, the grain looks ok. I think I may have over heated it and that caused it to warp. It was a very thin blade. Thinner than I would have liked, but being a rookie grinder, I was trying to eliminate some mistakes on it and it got too thin. Anyway, here’s some pics of the grain. Let me know what you think. It’s time to start over again. I guess a pid control on my forge is closer in the future than I was anticipating.

nqTichR.jpg
 
Last edited:
Why don't you just buy a bar of 1084 and forget the forging? It offers no real advantage over stock removal in your case.
 
In my opinion if your grinding the blade clean like that then I agree with Bill, start with clean bar stock and do stock removal, your grain on that piece looks pretty coarse, not what I would want to see after heat treating. After forging you should cycle the blade at descending temperatures to refine the grain for example 1650, 1550, 1450. Here are some examples of how grain may look at different stages, ideally you want it to be smooth and not grainy.4A637F88-3B5C-4C81-9EA5-FCEF9D733F7B.jpeg
 
Thanks, Joshua. I did normalize three times after forging, but perhaps I’m not hitting my temperatures correctly. I’m not giving up just yet. I’ll try again until I get it right.

I didn’t intend on grinding it completely clean, but I’m just learning to use a belt sander and I had to keep covering mistakes and it ended up clean. I do intend to learn to forge knives correctly.
 
Last edited:
Blackdirt cowboy said:
Thanks, Joshua. I did normalize three times after forging, but perhaps I’m not hitting my temperatures correctly. I’m not giving up just yet. I’ll try again until I get it right.

I didn’t intend on grinding it completely clean, but I’m just learning to use a belt sander and I had to keep covering mistakes and it ended up clean. I do intend to learn to forge knives correctly.
Click to expand...
Gotcha, I’ve been there on grinding to fix one thing only to make another mess for myself, for your heat treating make sure your working in low or no light when doing a forge ht, on your first cycle bring the blade up so a magnet just stops sticking and remember that color in your lighting then go visibly 2-3 shades brighter then work back on you second cycle to only 1-2 shades brighter then your final cycle go to where the magnet is just starting to not stick. Remember those colors and see what results you get for your grain if it’s still coarse then stop a shade earlier on your second and third cycles and see when you get grain that looks smoother like the factory ht above. You just have to keep testing pieces to learn what colors in your shop you are looking for, if you are working outside with natural light don’t start heat treating until it starts getting dark and try to work at the same time each time your heat treating a blade so you’ll start getting accurate results.
 
That makes sense. I forge outside and did my heat treating during daylight hours. I’ll have to try it at night and see if I can more easily tell a difference in the temperature of the metal. I may play with the blade that broke and see if I can change the grain structure of it.
 
You must log in or register to reply here.
Back
Top