First Knife Build

[Joe Albina]

Hey guys,

 

This is my first attempt at forging a knife. I definitely learned a good amount. Just wondering if you have any tips or critiques on the final product and maybe my set up.

 

My forge is an 11 gallon air tank lined with 2in of kaowool, coated with itc 100 with fire bricks along the bottom to set the piece on. I am running it with a venturi valve burner made from black pipe with a flared stainless nozzle. The burner is connected to a grill size propane tank with an inline regulator and pressure gauge. I have been running it at about 10-15 psi.

 

I only have a slightly rounded 4lb hammer with a tapered tip on the back side. Being worked on a too small 15lb anvil.

 

I made my first set of tongs out of half in square bar stock. They could definitely be better but they were the first thing I ever forged.

 

The knife design was developed as I went. I decided to leave around the spine rough and hammered because iike how it looks. To heat treat it I brought it up to temp so that it was no longer magnetic then immediately quenched it in water because I didn't have enough oil around. The grip was supposed to be pinned but I forgot to drill the holes before I treated it and don't have a bit hard enough to get through it now so I just went with epoxy. I didn't let it set enough tho before I started shaping it, so it started to separate on me. I am going to pull it off and get a tougher bit to drill it and pin it.

 

If you have any pointers or recommendations or critiques as to techniques, tools, heat treats, anything please help me out.

[Aiden CC]

Congratulations on your first knife! I like the profile and the forged look. For drilling holes in steel I recommend cobalt bits. In my experience they work better and last longer than HSS bits. Also, if the tang is too hard, you could temper it back (soften it) by heating it until a blackish-blue oxide forms on it with the blade submerged in water to make sure it stays hard. Four pounds is a little heavy for a general forging hammer in my opinion, but if that's what you have and are used to, use it. As you described it, I believe it is a "cross-pein" hammer.

 

Knowing what type of steel you used would help for heat treat advice (such as to do an oil or water quench). Its generally a good idea to use a known steel alloy when starting out to bypass the surprises of mystery steel. I heat treat with a coal forge, but its similar to using propane, in that there isn't a thermocouple or anything like that. Using a magnet is definitely a helpful step, I also try to do my heat treating at night so I can see the color of the steel better. For water quenches, I pre-heat the water and add a bit of dish soap to lessen the surface tension and reduce the jacket of water vapor that forms around the knife in the quench. I haven't had any blade crack, but I also have only done a few water quenches.

 

Out of curiosity, what did you use to do the cold shaping on your knife? Was it a 4x36 belt sander? That't what I used for my first knife, and I remember it being difficult to remove much metal. It looks like your edge was a little thick before you sharpened it. It's difficult to grind a thin and even edge, but you can practice on cheap mild steel (like the stuff you can buy at a hardware store). There are other makers on this forum much more experience than I am, and I'm sure they have a lot of good advice. Best of luck and keep at it!

 

Aiden

 

(Edited because I can't spell)

Edited December 28, 2015 by Aiden CC

[Joshua States]

Well, it looks like you've made yourself a knife......and a forge, and some tongs. I'd say you have a great start there.

Only a couple of things I could tell/ask you at this point, most high points were already addressed by Aiden.

1. 10-15 pounds is pretty high and you will run that little bottle dry quickly. See if you can run it lower to conserve fuel or add another burner.

2. Quench hardening is only the first half of heat treatment. This is followed by a tempering stage, where the blade is heated to specific temps for roughly two hours to "draw back" the hardness from quench hard to a usable hardness. A quench hard blade will likely be brittle, and that's if you used a tool steel to begin with. (What steel did you use anyway?) Tempering data can be found for specific steels from a variety of vendors and steel info websites.

3. Do you truly like that rough forged look, or did you just get tired of trying to grind it out?

4. Many stores sell Canola oil and although I don't have any personal experience using it as a quenching medium, I have heard many smiths claim it works well for simpler steels and is far less expensive than industrial quenching oils.

5. You have a decent setup (you do not need a huge anvil) to get started in this bizarre craft. I hope you continue with it and keep the project pics coming.

[steven smith]

Thats a good first knife aside from the grinder and burn marks, those can be cleaned up though, I like oak handles. You can soak your blade in vinegar to loosen up the scale in the hammer marks.

 

A handle with scales will need pins, and I don't harden my tangs, I think some people do but I really don't think you need to. I would anneal the tang and then drill it, but keep the blade cool, I would just use a torch, if you can keep the blade in some water while you heat the tang you wont risk ruining your temper. After you drill the first hole stick a pin through it to keep everything in place, you need to do that after each hole or your holes wont line up. And wait 24 hours for your glue to set because if something moves and then it sets you might have to destroy your handle material, I don't like to only rely on glue so I pin my handles. Don't overheat your pins when grinding the handle, they will burn your handle and glue.

 

Learn about decalescence, there are some good videos showing it on youtube, non-magnetic is just a neat thing steel does in my mind because you still have to get the steel hotter to quench, canola oil heated to 120F is a good quenchant. Try not to let the blade cool to ambient temperature before you temper it, and check that whatever you temper with doesn't overheat your blade, an oven set to 400 could cycle between 300-500 (thats a bit exaggerated but you get the point).

 

Your hammer might be too heavy for a beginner unless you already have a strong arm, it could lead to joint pain.

 

Good job forging tongs before forging a blade, I'm still using pliers and burning myself all the time.

 

Welcome to the forum joe!

[Robert D.]

Thats a great first knife. once you complete the first one, you will find that you cant really stop thinking about the next one, and the one after that, and the one 25 or so down the line....

About the only helpful information I can give you being a newb to this myself, is to read, A LOT on this site, the Stickies are a great place to start, a LOT of awesome information available from very experienced makers can be had in those threads.

Welcome aboard and welcome to a very VERY addictive hobby.....

[Joe Albina]

Thanks for all the info and critiques. It's good to know that the smithing community is so accepting and willing to help guys like me just starting out.

I intended to put the steel I used in the first description but I guess I forgot. I used an old crowbar that I had in the garage.

 

Aiden,

I actually used a 1in belt on an old sander set up I got from a golf course I used to work at. It made it tough to get it to be even as you said the 4 in did. I got it as close as I could. I will be getting a 4in belt and disc combo soon to hopefully make it easier than the 1in.

 

Joshua,

You mentioned about heat treating making the blade brittle. As i am attempting to put a finished edge on the blade it seems to be "chipping" along the edge. I could feel it when I tried to cut paper with it, and once I took a look at it under a loop I confirmed that it was indeed chipping. Could this be because I didn't temper it? or maybe the steel I used isn't good for making knives? I can get it sharp enough to be useable, but not sharp enough to be satisfied with the hone. And I really do like the rough forged look for my first blade at least, it helps my friends believe me that I actually forged it! But on future builds I will likely do a full grind.

[Alan Longmire]

All steel has to be tempered after the quench. That edge chipping you're getting is why. Untempered hardened steel is very brittle and can shatter just fromm sitting there.

 

Crowbars are tough steel, usually anything from 1045, 1060, or 5160. Yours was obviously not 5160 since it survived a water quench!

[Austin_Lyles]

Looks to be a great first knife for sure and it seems you've learned quite a bit! On your next knife make sure to get some pins on the handle in order to reinforce the wood.

 

Yes, assuming you didn't temper the steel after the quench, that would cause the chipping. Tempering is a very important part of the heat treating process.

[Joe Albina]

I took everyones advice and tempered it. I went out and got a toaster oven, set it to 360 and left the blade in it for about an hour and a half. Now the edge is clean of chips after sharpening and sharp as hell with a 30deg bevel.

 

I will be drilling and pinning the handle today as well as buffing the blade. I am still going to leave the hammer marks and scale up on the spine but most of it will be polished. Hopefuly it will look how I will want it to. I'll make sure to put up some pictures when it's complete.

 

Thanks everyone for all the help!

[Joshua States]

360 might be a little hot for the type of steel you have there (judging by Alan's assessment, and I'm not going to argue with him about it, that would be foolish!), but it will certainly allow for sharpening a wicked edge. It just won't hold that edge for a long time.

 

Let me explain a bit. Tool steels have enough carbon content (and possibly other metals) to allow the steel to become "hardened" after bringing up to critical temperature and then rapidly cooling. This is the first half of what we commonly call "heat treatment" (HT), or "hardening" the blade/tool/whatever. The second half of HT is called "tempering" or "drawback", and is where we heat the blade to a much lower temperature to soften the hardened tool to a usable level. Ideally, we want it soft enough to not break or chip, but not so soft as to loose it's shape under pressure or in the case of a knife, loose the sharpness of the edge from use. Hardness is measured in a variety of ways and scales, the most common (I think) is the Rockwell scale . Different steels have different tempering heat ranges to achieve specific Rockwell hardness levels (specified as RC followed by a number). Carbon level controls the hardening ability of most steels and is measured in "points" of carbon (100 points=1%). So the steel you have there (again judging by Alan's assessment) is a fairly low to medium carbon content "simple" tool steel (i.e. it is pretty much iron and carbon with maybe some trace elements in alloy). The medium/low simple tool steels get soft pretty quickly and would typically be tempered at around 220-250 degrees for two hours to achieve a RC level around 57-59. 360 is enough to push it past the desired level into soft range again.

(someone correct me if I got that wrong, I tend to forget this minutia and don't have my reference notes handy)

 

A simple test for whether the edge is too soft or not is to take a 1/4 inch round rod and lay it down on the bench. Lay the blade on its side with the edge across the bar and push downward flexing the blade edge around the bar. When you let up, the edge should return to straight. If not, the blade is too soft. If it chips during this test, the blade is too hard.

[Kenneth Mauldin]

not bad for a first!Keep it up

[Doug Lester]

If the edge is holding without chipping at 360° tempering temperature I'd say that you hit it on the nose. I started out with flat tongs (bought them; didn't make them) and found that they wouldn't hold the work well. Personally I like chain makers tongs because of their V shaped jaws The blade would have looked better if you had gotten all of the forge marks out. Some of them look kind of deep so I wonder if you are hitting the steel too hard, a symptom of a too heavy hammer and lack of control. Both common with first knives. Also there's only so much work that you can get out of a small anvil like you have but my first one was even smaller. My favorite anvil now is an 87 lb block of steel that I was able to obtain for, as I remember, $140 shipping included. See what you can scrounge in your area. Just stay away from cast iron ASO's (anvil shaped objects)

 

All in all, I'd say you did better than I did the first time out.

 

Doug