A Boy and His Crosscut

[Burnston]

Good afternoon all,

My five-year-old son decided he wanted to make his own knife and asked me for materials and advice. As far as materials, I gave him an old crosscut saw from the 1920s (as best I can tell,) a grinder, a set of files, tongs, and a small forge. As for advice, I had none to give as I am completely ignorant in the field of metallurgy, knife making, and blacksmithing.

He decided to heat treat and shape a blank, stating that he's not to ready to try forging. He began by carbon testing his saw, first with his file, then with his grinder. Then we cut out a blank and used a grinder to get his rough shape. Using his hand files, we began shaping his edge while his fire (oak wood) heated up. He used his tongs to situate the wood in such a way to create a discernable chasm within the fire in which to place his steel, which he did after a reasonable heat had been achieved. Bear in mind, we were eyeballing everything.

While his steal heated up we began cutting out more blanks, anticipating our first one to be trial and error at best. Here is the short version, and questions we've developed-

1. His first blank got way too hot, cracked in the quench (5w-20 engine oil) and broke when we dropped it on the concrete floor.
2. The second hardened up and passed the file test, so we tempered it at 400 degrees for approximately an hour. He broke this one trying to correct a bend.
3. Finally, repeating the above process a few different times, we were never able to get out hardness right, and every blank since has been soft, so much so that the point blunts and edge roles at the slightest test.

Being as he is five, I would like to see how serious he is before I start putting serious money into more sophisticated tools. Besides, he is quite happy trying to figure these things out "the old way." That said, will any of you old hands please share a little advice? Given the materials/process we have on hand, what can we do to find that happy medium so that he can have something functional and long lasting that can withstand his 5yo judgement in the woods?

Please, those of you willing to render some advice, speak as you would to a toddler. This is for my sake, as I am completely ignorant on this subject, and far below what one might call amateur status.

 

[Crag the Brewer]

Not sure what to make of This.....?

Everyone has different capabilities, if you, and uncle, or a neighbor was a professional Knife maker, machinest, artist, something.....I'd be all over this, and full of encouragement..I've been making chips since I was around 8.

But, Yeah.....idk?
Not sure what to think?

What do you do for a living, If I may ask?

 

[Burnston]

Rancher; we raise longhorn cows. While hand tools and “making do” are tools of our trade, the heat treat/tempering process has me stumped, thus the above cited situation. As for what you want to make of it, I suppose that is up to the reader. Just seeking general advice for a boy interested in making his own knife.

 

[Crag the Brewer]

Rancher; we raise longhorn cows. While hand tools and “making do” are tools of our trade, the heat treat/tempering process has me stumped, thus the above cited situation. As for what you want to make of it, I suppose that is up to the reader. Just seeking general advice for a boy interested in making his own knife.

Ok, thanks for answering. I didn't mean to sound rude or condescending, but maybe my advice might be different if you were an accountant?

Lots of people seek out and read Larrin's book.....here's a link to his website

Introduction to Knife Steel Heat Treating from a Metallurgist - Knife Steel Nerds

Heat treating is easy and I can prove it - I taught my seventh grader son how to do it. You can heat treat knives too!

knifesteelnerds.com

In This instance maybe your best advice might come from his father, a well know, talented knife maker Devin Thomas. He would be able to know about as good as anyone, and was very successful....

D DevinT
Hoss, Any inspiring advice for youngsters?

 

[Stacy E. Apelt - Bladesmith]

I grew up on farms, and have worked cows and horses as well as farm crops. I started forging at 11. One of my earliest knives was from an old crosscut saw. Just want to verify I know the lifestyle.

That said, I don't think giving a 5-year-old a forge and telling him to figure it out is wise. There is a ton of stuff online (and in this site) about how to make a knife. YI bet he will remember this a lot more if you checked the info out with him and learned to make a knife along with him.
Every topic that you had trouble with is in Shop Talk's Stickys.

As to your HT - It was almost surely way too hot. Use a magnet to determine when to quench. As it starts turning reddish, pull it every 10-15 seconds and touch it to a strong magnet ( cheap welding magnet). The steel will stick on the magnet. When the steel won't stick to the magnet - QUENCH! BTW, lump charcoal ( not briquettes) is a better fuel for the forge. What type blower is on the forge?

The HT is where steel turns hard. After the quench it is very brittle. drop it and it shatters ... bend it and it snaps easily ... leave it siting on the bench overnight and it may break on its own. Immediately after the quench (within 10 minutes) you should temper at 400° for one hour and then cool it in water. Put it back in the oven and repeat the temper again another hour to make it fully tempered (the why of that is in the sticky threads about metallurgy and HT.


After HT, you won't be able to use files, as the steel is harder than the file. Use the grinder and/or Silicone Carbide sandpaper (auto parts store). When grinding dunk in water every pass or it will ruin the temper on the edge.

As to your quenchant - Used motor oil is a really poor quenchant. For the steel in an old crosscut saw it may not even fully harden the steel. A gallon of Vet Grade mineral oil will be a better choice (I am sure you either have it or can easily get it.). If you are brave and can stand a few cracked and broken blades, the brine quench info is also in the sticky's.

Here is a basic tutorial I wrote a while back:

In teaching new smiths how to HT in a forge, I find that they frequently do one or more of these things:
They tend to pull the blade too soon when it is unevenly heated.
They greatly overheat the blade when judging the color by eye.
They only get the edge hot enough and by the time the blade gets to the quench it has dropped below critical.


Often these "lessons" are done over the internet and here in Shop Talk. This makes it impossible to physically show them what it should look like as you would in a hands-on session. Normalizing is pretty simple to teach online because temperatures can vary and a bit too high isn't disaster. Hardening is a bit harder when close temperature control is needed.

When using a magnet as the guide to when a blade has reached the transformation point while rising in temperature, the main point I try to instill is that the blade must be EVENLY heated so all the blade is the same color as it transitions from pearlite/ferrite/martensite to austenite and then converts in reverse as it cools and hardens in the quench. Uneven heating and cooling is the main cause of warp and twist. It is also important to watch the edge and avoid overheating it.
When using a HT oven, I use the charts in Larrin's book now. I used to use the ASM Heat Treaters Guide and used the minimum temperature listed. Larrin's figures are far better for knife blades. Larrin has also done research on hardening a blade in a forge.

When advising people doing any type of HT I recommend getting the pre-hardening condition right first and then using the lowest temperature needed for full austenitization. You can find great advice for normalizing and thermocycling a blade in Larrin's book or in a search using Shop Talk's custom search engine - https://cse.google.com/cse?cx=012217165931761871935:iqyc7cbzhci

How to use a magnet when doing a forge HT:
The magnet I use is a square welding magnet that I stick on the bottom or side of the forge near the port. Any strong magnet will work. Place it at a convenient location so you don't have to take the blade out for long.
Let the forge fully soak the refractory for a good 15 minutes. This time can be used to forge some small blades or such. No need to waste time and propane! The important thing is to get the forge interior fully soaked. This makes a more even and stable environment for the HT. I often shut the forge off as the blade starts to turn red and just use the internal heat from the refractory to bring it up to final temperature. This works well with most forges. A really useful addition to a venturi forge is a propane rated solenoid valve to turn the gas on and off. Run the valve with an On/OFF foot switch. This allows you to shut off the gas for a short while and then relight the forge with a step on the pedal again. The hot forge interior will immediately relight the flame. I use this in forging as well. A plus is you get to see the actual color of the blade and not have the flames in the way. I keep a butane candle lighter nearby for when I have it off too long to relight automatically. For the ultimate forge temperature control conversion , read my PID Controlled Forge plans in the forge info section of the Stickys. It can run a good forge almost as close as a HT oven.

Doing HT in a forge - Once the forge is evenly soaked, turn the forge down as low as it will go and hold a stable flame. In most forges this is still too hot for HT, but it is as low as it will go. (see above paragraph for options)
Let it run at this temperature for five minutes or so while you get the quench oil tank in position about 2 feet away from the forge and to the right or left. I recommend "smithy" temperature (50-100°) Parks 50 as the quenchant.
Well before the HT session, coat the blade with a coat of Turco-II or a slip wash of Satanite. I am sure ATP, Condursal, Brownell's, or NuClayer is just as good. Allowing the coating to fully dry on its own is also a key to success. (I won't go into all the reasoning for a coating here, but it has advantages.) I have experimented with NuClayer and find it excellent, but the cost is a bit high for some hobbyists. Satanite works almost as well and is cheap. Most of us with a forge already have a bag of it. Make a wash that is the consistency of a melted milkshake and coat the well cleaned blade with it. Let it dry for several hours. I dry them overnight. The thin coating evens out the heat transfer as well as cuts down on decarb.
My basic home-brew Turco-II recipe for the wash is a cup of denatured alcohol, a tablespoon of Satanite, a tablespoon of boric acid, a teaspoon of yellow ochre, a teaspoon of powdered charcoal, a teaspoon spoon of gum of tragacanth.
A simpler mix of equal amounts of Satanite and yellow ochre with water works quite well. I mix a pound of Satanite and a pound of ochre, then add water slowly as I mix it well. If not thick enough, add more Satanite. If too thick, add more water. You can keep this in a jar and use it for a long time. Adjust the thickness as needed.

As you heat the blade, turn it over and over, move from side to side in the forge, shove it in and out, and try to heat the spine more than the edge to allow the heat to run to the edge. If a spot gets brighter color than the rest, move that part of the blade to a cooler area in the forge.
As it gets an even dull red color, start checking the magnetic state. Pull the blade out and drag it across the magnet from ricasso to tip and right back in the forge. If it is still magnetic the feel is a resistance from pulling to the magnet. As it hits the right shade of red (far less bright-red than most folks realize!), it suddenly stops being attracted to the magnet and just slides across it smoothly. Immediately quench when it reaches non-magnetic. Hold it in the quench while pumping it up and down for at least 10 seconds before pulling it out. If it is a large blade and still smoking a lot, leave it under the oil until the smoke has stopped.
(once out of the oil you have a short window to check for warps/twist and correct them before the martensite starts to form at 400°)


Side note - if your quench is smoking or flaming it is not the blade causing it - it is that you are getting the tongs too hot. After forging, straightening, and then doing normalization, the tongs can get pretty hot. Switch to fresh cool tongs before starting the HT. I often switch tongs just before the quench when the blade gets evenly red and is close to non-magnetic.
Lots of smoke or a puff of flame, à la FIF, is a sign that something is WAY too hot. From HT temps around 1500° the blade drops to 800-900° in a second or two, so it is almost surely the hot tongs above the oil igniting the oil vapors.
A quench tank that is not deep enough or large enough is the other cause. The optimum tank should be 12" deeper than the blade is long. A minimum volume for small blades is 2 gallons of oil. For big or long blades, 5 gallons is usually needed.

 

[Horsewright]

No idea what you are talking about, ranching what's ranching?

Here's a longhorn for ya, my son's got roped:

Anyhoo just a few gratuitous cowboyin' pics for ya and Stacy always digs em. Youngsters can learn to do these things with your help as Stacy suggested. Young lady getting ready to heel that calf above is 7! My son on the right was 2 when he roped his first calf at a branding. He was sitting in front of me on my saddle. After he roped the calf I had him hand me the rope and I dallied. He did two and then wanted to get down and play with the other kids. He's 34 now and has always been a working cowboy. You are in good hands here.

 

[Ken H>]

A very good write up Stacy, and Dave, we ALL enjoy your ranching photos.

I missed where the OP mentioned having a blower - he wrote:

"we began shaping his edge while his fire (oak wood) heated up. He used his tongs to situate the wood in such a way to create a discernable chasm within the fire in which to place his steel, which he did after a reasonable heat had been achieved. "

That sounds much like a fire made with oak wood, not something like a forge. I suspect the OP might have used a blower to get the blade glowing red?

 

[Burnston]

Good question, I apologize for being unclear. I made a makeshift “blower” out of 5ftx1.5in steel pipe connected to a 12in leather bellows I restored sometime back. Also, as a point of clarity, I was involved in a supervisory capacity during the whole project. I do not want to come across as turning a 5yo loose with such tools/dangers all alone with naught but a “go figure it out” suggestion.

To all who have responded, you have my sincerest thanks. You’ve been very helpful; he is very eager to implement these suggestions, and read up on the proposed literature.

 

[Ken H>]

Good response, and from your statement "we were eyeballing everything." I sorta assumed it was a joint effort, and at least closely supervised.

Leather bellows? Ya'll are going old timey for sure. I've read about some folks using a leaf blower, or even the exhaust of a shop vac for the blower. You can surely get good heat that way. Ya'll have fun, and learn lots along the way.

 

[DevinT]

Five years old is a bit young to be making knives. I applaud you both for trying.

If I were to help someone that young, I would do 30 minute sessions over a period of weeks to make a knife.

Heat treating is definitely a very exciting part of knife making. Heating the blade and quenching in oil with a flash of fire and smoke is fun to watch.

The shop or work area should be dimly lit so you can judge the temperature better. Or work at dusk.

“Cherry red” is pretty accurate for color when heating the blade but only works when it’s dark or dimly lit.

Try for even heating, you’d be better off quenching in hydraulic fluid. Clean the blade after quenching and temper in the kitchen oven at 400’ for an hour.

As much as you want to, this is the worst way to heat treat.

I suggest you find a knife you both like and copy it.

Start with a small metal working file. Draw some of the hardness out of it by tempering in the oven at 475’.

The best thing to do would be to find a bladesmith in your area to help you.

Hoss

 

[Stacy E. Apelt - Bladesmith]

Burnston,
Looks like you are doin' it right.
If you plan on learning to make knives along with him, send me an email. I'll put a kit together for you with some materials and a few good books on getting started. sapelt@cox.net


Sorry to side track your thread. Dave and I get sentimental regularly.

Dave, I love your photos. You capture a working ranch better than I think a photojournalists could.
I wish there had been a way to take photos all day at the farm when I was young. Cameras were expensive, film was expensive, and developing was expensive. Photos were saved for special occasions, like a birthday, graduation, or special trip. Many people never took a total of 100 photos in their whole life. Some folks never took a single photo.
Today people take multiple photos of everything that goes on around them, even their dinner.

Besides a few photos I took of the kids and Miss Agnes feeding the geese and chickens at the farm in the 70's, there are no photos of the Menzel's or the farm that I know of.
The farm is all in my memory now.
We buried the last horse, Star, in 1975 ... she was 30 years old. I rode Star from around 1960 until the early 70's. She was a quarter horse, and an amazing ride, but had done only plowing and pulling a cart and buggy the first half of her life, until a tractor replaced her and they put her out to pasture to retire. I ended that retirement. They got her as a yearling for free from the government when the war was over. They saved it from becoming dog food. I vividly remember putting a chain on it and dragging it down to the bottom of the pasture while Claude dug a big trench with the backhoe. We pushed it in, covered it up, and went to have dinner. No funeral or last words. It was a farm animal and that was that. I do miss visiting her. I always cut up a pear or apple and put the pieces in my pocket. She was old, but would brighten up and get frisky when I came. No one but me rode her since around 1960.
All the livestock has been gone for 40+ years, the barn torn down 25 years ago. I drove by the old place last year and almost cried ... the house had been torn down and a modern home with vinyl siding was where it had stood since 1903. I still own some of the tools they used to build the house with, along with some of the collars, tack, saddles, and swingle trees from the mules and horses. In my shop I have the carbide box off the 1903 Ford. I electrified it and put a flickering bulb in a lamp chimney on the top.

Before I had a real horse to ride, I had a "Buckin' Barrel" in the 50's. It was a 55-gallon drum with four strong rings welded to it. Ropes were tied to the rings and run to nearby trees. The top of the barrel was probably 5 feet off the ground, which was pretty much like a horse to a 4-and-a half foot tall kid.. It took some skill to mount it without a step-stool. I had an old pony saddle I found in the barn at the farm in New Hampshire and somehow convinced my mom to let me bring it back home to Virginia. That was strapped to the barrel and four friends pulled on the ropes hard as they could to make it buck. After the second sprained wrist and one broken arm amongst all us cowboys, we had to stop bucking on it. It then became a regular horse. Since every boy had a lasso (due to the cowboys on TV and the movies), we practiced roping on each other. One kid got on the "horse" and the others ran around the yard as the heard of cows. You were the cowboy for three throws ... and then it was your turn to be one of the cows. Besides a few rope burns, that proved to be a much safer game than "Buckin' Bronco"

OK, I think it's time for a single malt and a good book.