Hog Splitter From a 12" Saw Blade
by Just Nathan in Workshop > Tools
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Hog Splitter From a 12" Saw Blade
So, why would you want to make this? Do you like bacon? Would you like to be able to make your own? Why would I even ask that question? Why would you make anything on this fantastic site? Can I write a sentence that's not a question? Should we find out?
Well, I didn't exactly find myself in need of a three-foot cleaver all of a sudden, and then just happen upon this sweet used blade. More like I saw the blade and had to explain to my wife why I was digging a dangerous, used, steel death-maker out of a dumpster and putting it in the car. This splitter was my excuse. It wasn't a very good one, because I've never done anything like this before (unless that rad katana counts), and telling her that I wanted to use power tools, blistering heat, and even MORE saw blades to turn this dull saw blade into a hybrid axe-knife didn't exactly ease her worries.
So I was just notified by myself that I've written too much introduction and not enough instructable.
Let us begin:
Gather Your Tools
You'll need a saw blade. Obviously. If you don't have one, just breathe; practice mindfulness. We'll get to that part next.
Other than that, you'll need:
1. A hacksaw with a couple18-24 TPI blades
2. Massive biceps/triceps/pectorals/rhomboids/sigmoids/hemorrhoids etc., or a lot of time and Advil.
3. A permanent marker
4. A ruler
5. Imagination
6. An audiobook with good headphones
7. A bench grinder
8. A belt/rotary sander
That's about it for now. This project is on-going, so I'll add on the next part when I get there.
Find a Saw Blade
I recommend running around a neighborhood a few days a week, especially if you've figured out which days they pick up the big items. No, I literally mean running. It's good for you. Whoa, okay you can walk or drive, it was just a suggestion (jeez). If you decide to run, plan on making time afterward to drive back along your route and gather whatever cool materials/furniture/toys/bicycles/junk you might have spotted along the way.
If you have kids, borrow a stroller until you find one of your own, pack some popsicles and books, and then get really good at reorganizing things as your new hobby bears fruit. By fruit I mean smelly things that you should wash before bringing into the house.
You should pay close attention to construction site dumpsters, but try to ask permission, be very cautious (there might be nails or heaven-forbid loose saw blades in there), and leave the place even cleaner than you found it. You'll become a welcome face if you follow that last rule. Or be nick-named Lockjaw Lindsay if you break the second rule.
You could also just buy one of these babies, but they cost upwards of $40. So why would you?
http://www.homedepot.com/p/DEWALT-Construction-12-...
There. Follow the hyperlink if you have to.
Make a Plan
With your ruler, plan out a way to maximize blade size and handle length. No, it doesn't have to be as big as I made mine, and you can always skip dessert and sleep without a pillow if you had to, but what's the point?
I chose to simply not care about the arbor hole in the middle. I just don't. You could place your blade in such a way as to use the hole for hanging the finished cleaver, such as you might see in many cleavers, but your blade size would suffer. Perhaps you don't feel the need to compensate for having a small vehicle, or whatever that whole joke is about, I never can follow that sort of thing.
I ended up planning a two-piece tang to be welded together later.
Do your best to avoid the tungsten carbide teeth if you can, as they are nigh impossible to work with and won't be as inconspicuous as a good set of standard dentures.
Come to think of it, I could have left them on one side of the blade for cool-looking and meat-tenderizing purposes...but I didn't. It's probably better that way.
Hack Away
What are you doing back here already? You know what to do; go do it. You already planned it out, just saw away.
What?
You just clamp it down on a work table.Yeah, if you've got one, or just a piece of plywood across two sawhorses; just clamp it there so the line you're going to cut sits free, and then saw at it.
Oh my gosh, really? I said it would take a while. Darn right it's difficult, but I believe in you.
Alright, if it helps, I'll go into more detail. You'll be better off if you wear gloves, as you're going to end up with some hot spots if not outright blisters. Just go light and slow to start off with; no need to dig in just yet. Let the weight of the saw do the work until you have a healthy groove going, and then just put your head down (and goggles and mask on) and just saw away.
If you find yourself making slower progress after a few cuts, you could try spraying a little WD-40 (in your armpits. Just kidding. Or AM I?) or maybe changing out your hacksaw blade. If the hacksaw starts to twist or rattle, tighten the nut by the handle, or change out the blade for one that doesn't look like it plays hockey.
And then just get lost in the zen garden of muscle aches and steel dust you're cultivating. Let it center you, as you will probably start to pull sideways as your arm gets tired. Before you know it, you'll be done. With this part.
You could also spring for an angle grinder or a tub of cut-off wheels for your Dremel, or a massive cut-off blade for a circular or radial saw, but whatever; if you're gonna be that way then fine. Do it your way.
Plan Out Your Sweet Curvy Shape
You can discard the extra pieces now, or use them for some other project. If you live in Mexico City and are building a cement wall, consider using them to line the top in place of glass shards, and if that's bad advice, then I didn't say that and you made that up.
Fit the pieces together how you planned it, and then get fancy with your marker again. Consider which corners need to be distinct, and which ones you'll want to smooth out. Also, check out some images of hog and beef splitters, as well as normal-sized cleavers, select examples of styles and flourishes that you like, and take an art class with a curriculum that is exclusively designed around drawing free-hand curves in permanent ink.
Or just wing it like I did, and adjust it as you go. You'll want to be careful in planning to eliminate large portions of metal. There's no easy way to tell you this, but this next step is a doozy...
You'll have to grind away everything you don't want in the next step.
That was actually pretty easy to tell you.
Get Grinding
First step when grinding is to not wear enough protective clothing on your arm branches, so that you can get some manly looking burn freckle scars. I've taken a picture of this step because it's so important. Next step is to put on a dang coat. You should already be wearing safety glasses, a mask, and a beard for safety's sake. You'll see my beard deftly catching a spark in one of the pictures. Trained it myself.
Once that's all done, have at the pieces with that bench grinder. Try and make even passes with good, even pressure, and you'll start to see the extra material leave this plane of existence to wherever metal goes when it dies. Probably the floor and your work table. Metal doesn't go to heaven. Also keep in mind that it would also be going in your breathe-bags and smooshy cameras if you weren't wearing a mask and glasses. Bet you didn't think about that, huh?
If it starts to glow-
Yes I know it's sparking, that's the point, but if you see the metal GLOWING a reddish color, then dip it in some water. In fact, do that every so often anyway just for kicks.
Pretty soon, you'll either be done, or will have decided to not make it quite as fancy as you'd planned, and it'll be on to the next step.
Sanding
Alright. Turn on your sander. Now turn it off. You forgot your mask and glasses again Jason, get with it, will you?
The rest of you, while we're waiting for Jason, pick up your blade section and prepare to do an even sanding job that runs perpendicular to the blade edge.
Alright, turn it back on, and, holding one side to keep it from flying off, lay the piece face down along the belt so-
(Sigh) That clearly wasn't tight enough, was it? It's stuck in the box over there; the one marked "Textbooks."
Hold it tighter this time, and push it gently but firmly against the belt with a gloved hand. Give some thought to how you'll be using this beast; if it's for chopping wood, you'll want a narrow blade for a much finer edge; if it's for hacking through bones and meat, you'll want the edge angle to be rather more obtuse. For now though, you can just do some freehand shaping with the belt. Tilt the spine of the blade up a few degrees to just start removing some of the material along both sides of the blade. It doesn't need to be sharp yet. Then go ahead and do some flat sanding on the other pieces as well.
Once the paint is gone, the edge is roughly shaped, and you have a shiny, fresh surface all over each piece, use the rotary sander to even out the edges where you'll be welding. Or somebody will be welding. Don't worry about that now, just sand it.
Once you've done that, place the pieces together, and step back to appreciate your work. Not bad, huh?
Just wait till we get the next part done!
To be continued...
Check Yo Steel - Method A
And now to test your loyalty to the cause: Let's talk physics and chemistry!
Iron is an amazing element all by itself: It's strongly influenced by electromagnetism (which is important for our project), and when you get its electrons all spinning the same way, it becomes a magnet also.
It's also the basis for your bodies ability to oxygenate itself, as it's the active part of your red cells' hemoglobin molecules (which has both nothing and everything to do with our project, because...you know...yeah, you get it).
What's really cool is when you add some carbon molecules to your bowl of iron molecule cereal. It suddenly goes from Tom Cruise to Terry Crews, and that's quite a step up. The carbon allows the steel to crystallize under the right conditions, making it both hard and brittle.
The amount of carbon we need in our steel is anywhere from .5% to 2% maybe, which includes some of the medium carbon steels and some of the high carbon steels. Not enough carbon means that it can't be hardened, with heating and quenching, and too much carbon means that we can't get a good weld. It's a rather delicate dance between those variables, like when you had to dance with your great Aunt Beth and you never knew how well her colostomy bag was clipped on, so you didn't want to jostle her too much but if you didn't tire her out she'd still be ready for a SECOND song at your uncle's second wedding and so you...
Sorry.
So we need to find out how much jostle is in our dance. The first way is the spark test, and there's a good illustration I've included that comes from the September 1959 issue of Popular Mechanics, in an article by C. W. Woodson; a fine name if you ask me.
Take a cut off piece of your saw blade-
One of the junk pieces, Jason; the junk pieces.
Then give it a good grind on your bench grinder. Watch your spark pattern: If it shoots out spaghetti sticks, you've got too little jostle in your step; if it shoots out a blinding cloud of short white streams that explode into dandelion thistles of smaller white sparks, Beth may have quite literally cut loose on the dance floor. Cut right loose. All over the dance floor.
Somewhere in between medium and high carbon on that chart is just fine.
Now go get a mop, Jason. (My gosh, he just gets in the way, doesn't he?)
Check Yo Steel - Method B
Alright, if you've got a blade that looks like mine, a 12" from DeWalt, with the tungsten carbide teeth, then you might just be able to trust my own results on this part. MIGHT be able to trust them. Since the tiny tungsten carbide teeth are harder than Grape-Nuts, they do all the cutting, really, and the steel just needs to be strong enough to hold on to them. That means a couple things (one good news, one bad): the steel likely won't be the highest of high carbon steels (that's good for our purposes), and the companies that make them might not have to be as consistent in their iron to carbon ratio with each batch (that's bad for you).
Since our splitter is more meat axe and less sushi knife, we'll be whacking into things instead of slicing, and we can stand to sharpen it more often at an easier bevel. That's why the medium-low carbon steel is fine for us, and also why we should be able to get a good weld without much trouble.
The inconsistent recipe means you might want to do this hardenability test anyway.
For this, you'll need some more tools:
- A torch (MAPP, propane, oxy/acetylene, whatever you've got or can borrow)
- Alternatively, a 2' deep hole in the ground with an air hose burrowed in to the bottom of it attached to a reversed shop-vac or blow-dryer, and the hole filled with burning charcoal
- Pliers
- A medium sized metal bowl of peanut oil, canola oil, or even motor oil
- A magnet you don't mind screwing up
- A hammer (but real professionals use their wife's 5 pound dumbbell)
- A file
- A vise, a strong clamp, or an offset ledge of concrete
Jason's mom took over for this step, so watch your language please. Gloves, glasses, and at least underwear, everyone. Underwear and a coat. Now hold another junk piece of saw blade with the pliers, and heat it with the torch until it not only glows cherry red, but...get ready for this...IT STOPS BEING ATTRACTED TO MAGNETS! Yeah, I know! Who could ever stop being attracted to magnets?!
This is the signal to very quickly quench the steel by submerging it in the oil. It'll smoke, but it'll kick the habit quick.
Now for the test: First, file the steel, to see if you can scratch it (if you can, you may have played around too long with the magnet), if you can't, then smash that sucker with the hammer. If it shatters, then success! You have enough jostle in your step to tire out old Beth. If it doesn't, then try heating again and quenching it quicker. If it still doesn't work, then have Jason's mom swing the hammer, because come on!
If it still really doesn't harden after all that, then you might just need new steel (oh, let's not even go there, that would be heartbreaking to lose you after this long; I don't even want to think about it; shut up).
Assuming it shattered, you're good to move on to the next step:
Welding!
(Or if you don't know how yet (as I don't)):
Waiting for the welder to order the right type of welding rod!
That's just not as exciting to yell.
To Be Continued...
Clothes Shopping...LIKE a MAN
While still waiting for the welder to arrive, you might as well decide what the handle will be made of. You've got plenty of choices: barbed wire, a hollowed out mannequin's arm, nothing, a boot, and plastic wrap. All of those are things. I recommend plagiarizing a little bit though, as sometimes the old techniques work best.
Wood is good. Micarta is something, probably good. Micarta, if you're unfamiliar, is typically a lamination of cloth layers with some type of epoxy or liquid fiberglass gluing each layer to the previous. HDPE can also be used if you want to get all recycle-y about it. It's a high density plastic that many milk jugs and plastic grocery bags are made from. You can cut it up and melt it, then carve out shapes that you like.
Seems cool. Doesn't really fit the project.
So I'm back to wood. Pallet wood that is (black gold, Texas tea), because I'm one of those guys. If you do have pallets, and are not yet a connoisseur of that delicacy, here's a tip in the form of a rhyme I'm about to make up:
If it says DB or HT, you're home free,
It it says EPAL, it's a great gal (sorry, that was lame),
Anything else...(I've gotta make this good: anything else...your mom's a...a melse? Welse? Melts? Melts!)
Anything else, and your face melts.
And that's why I stick to poetry about feelings.
DB: debarked, and HT: heat treated indicate that there were no toxic pesticides or cleaners or anything applied to the original pallet upon construction. No guarantees about after the fact, honestly, so it's always good to give the wood a wash before using it in any food preparationy sort of way.
Hard wood pallets are nice, and will typically be found under piles of bricks. The slats will also be rather thin compared to other pallets (because they're strong), and you won't be able to make a substantial dent in it with your thumbnail.
To make things easy, have a 2 year old take over your work space (as you'll see in a picture above), and then realize that your handle won't fit on the paper you selected for your handle mock up. Gently swear under your breath. Move somewhere else and use a strip of cardboard instead.
Now go pin the tail on the donkey-
Whoa! Jason's back. Lemme clarify: Not a real donkey. No more metaphors, because metaphors cause confusion.
Find a suitable board with some nice grain patterns, and then mark the silhouette with a sharpie. You could use a hand saw, but I just used a jigsaw to cut out the handle piece (which has now become a scale. Yes, a scale. That's just what you call it now. I don't know, just keep reading!).
I cut four in fact, because I wanted to have a selection of wood grain patterns to choose from.
Move along now. Next step.
Make That Wood Pretty...LIKE a MAN. No, That Doesn't Work As Well This Time.
Can I tell you a secret? I'm gonna tell you a secret. I've been thinking about this for days, and I can't get my mind off of it. What does my knuckle look like on the inside? You ever wonder about that? I had to find out. So I didn't wear gloves when using the belt sander. I know right?! Brave! That the word I would use too.
So, it looks like blood. Just blood. There's some pink and white in there, but mostly you'll just see the blood part.
So PUT SOME GLOVES ON!
There. Lesson learned.
As that well-known scripture states:
"With glov-ed hands, lay thine scales to rest upon the endless passing of roughened cloth. And with thy glov-ed hand give press with divine unyielding power. Thy servant scale, in shameful state, betimes repenteth his corruption. Thus, loving hands and pouring sands and ardent time conjoin; thy wretched servant scale shineth pure again."
Amen.
That was more Shakespeare, I guess. "Shakespeare reads the bible," maybe.
So, using the belt and rotary sander, shape the scales down to where your sharpie line is. Not all the way to where the tang/handle will be, you'll do that at a later step.
Then, sand your scales down to uncover the nice wood beneath, and pick your favorites.
And here's the cool part: Put it all down and leave the garage and go to bed because there's really nothing left to do tonight. The welding just HAS to come next.
To Be Continued...
Welded! Now Let's Bake
If you happen to be able to weld, then have at it. I won't interrupt. Just fill up your weld pool and take the pieces for a swim. It'll be a good bonding moment for the whole family.
If you're learning to weld, then I've got a couple points for you to keep in mind:
1. The higher the carbon content of your steel, the more likely the weld will form a crystalline structure with very high levels of stress. It will be a brittle bond, and it is likely to break if air-cooled. The best way to do a high carbon steel weld is to do preheating and post-heating, and that is just not something I'm ready to talk you through. It'd be better if you sat down with your parents and sweated through that awkwardness with people who love you. And I don't. You're great and all, but a relationship takes more than a great personality. You also have to be really, really attractive for it to work.
2. The metal of a saw blade is rather thin, and it requires a good deal of care in choosing the right welding rod. The temperature matters, as well as the steel makeup and the method of preventing excess oxidation during the process. You'll need to read up on that yourself, because I am no expert. About this at least.
If you're unable to weld it yourself, then find a company in your area who's willing to work with you. Such a small project might not be the highest priority on their to-do list, but they'll get it done. The company I used, Tallahassee Welding and Machine Shop, used TIG welding, and appear to have used stainless steel rods. They were a great group to work with, and I'd recommend them for anyone who's local.
First thing when you get it home, before you start wielding the Power of Greyskull on anything you see, put your cleaver in the oven. You'll want it to reach about 500 degrees Fahrenheit and hold that temperature for an hour or so. This should serve to relieve some of that stress that has developed in the welds. After the hour, just turn off the oven and leave it there for a couple hours, until it cools. And then do it again. (Professional tip: Don't start this Thanksgiving morning, as you will get in trouble.)
At this temperature, your cleaver will have developed a transparent layer of iron oxide with a rather comely shade of blue. It's a little enchanting that steel can predictably be colored in this way but controlling the time and temperature.
To be candid, I should have left it there. I could have just drilled the holes in the handle (which took forever and should not be rushed) and skipped the rest of the heating process.
It was still sufficiently hard for a cleaver, it was wearing its finest prom dress, and would have served very well for my needs.
But no...
I had to push on to the next step.
To be continued...
Heat Treat. Learn From My Mistakes.
This is where things get the sketchiest of sketchy as far as following my example. If you have any other way of conducting a heat treatment besides my method, then go with that.
I'm guessing though, that you'll bump up against the same problem that I did, which is, "Holy Massive Blade, Batman, where could we possibly fit this thing?!"
To which Batman would respond that you were an imposter and that he knew right away that you weren't Robin because you weren't wearing spandex and that he used to watch that TV show where you were an alien in a kid's body so he knew your face right off, and that John Lithgow was always the funny one anyway.
Since it's a cleaver, and since you already did a temper in the last step to ensure that the steel has some flexibility, you should probably go with an edge-only heat treat and oil quench. That makes this a little easier.
Actually a lot easier than what I did. I dug a 2'x2'x3' pit in my back yard and fit the entire bloody beast into it. I dug a tunnel at an angle into the base of the pit and shoved a PVC pipe halfway down. A reversed shopvac served as my blower for raising the temperature up to forging levels, and that attached to the PVC. A charcoal fire will theoretically work well for this (since it has for millennia before me).
And now the problems:
- It's hard to heat this thing evenly
- It's hard to control such a big blower to maintain forging but sub-welding temperatures
- This blade is a fine thickness for a pocket/kitchen/camp knife, but thin for a cleaver
- My quench oil was not hot enough when I used it (I forgot to throw in the RR spike I had heated up just for that purpose)
- It's a DANG BIG KNIFE.
All of this means that you'll have difficulty getting the whole edge hot without it also starting to melt in at least one spot, and that when you do quench it, the powerful changes in temperature will warp your blade like a 1990's grunge rock concert.
It may just break your heart.
Some tips for your own blades:
- Dig a hole just big enough for the cleaver blade
- Use a smaller blower (or add a dimmer switch to your vac), and be patient with your heat build up
- Clamp 2 pieces of thicker steel to the blade just above the level you actually want to harden (to reduce warp and to slow the quench of the upper section of blade.)
- You do have a very short window just after quenching in which to unbend some of the warping, before the crystallization is complete, so be ready with some sort of clamp or fulcrum spot for making quick adjustments.
Warp Triage
So yeh gat yerself a dadgum warpy blade, have yeh? Well doncha worry yer pretty little head there, missy, cuz ol' Catfart McGinty'll fixer right up.
Somewhat.
The idea behind this is that slow and steady pressure over a period of a few days can make a great deal of difference.We want to over-correct the bends by clamping the blade between two boards with spacers on the outermost sections of bend. This will slowly bend the warps in the opposite direction, letting it settle somewhere in between (hopefully back straight.) Clamp it this way just finger tight, not wrenching the clamp handles all the way, and then tighten it somewhat more the next day. Apparently, some people will even run a torch along the spine to help it loosen up some what, 'cause only the good die young as the great Billy Joel got paid to sing.
Take as long as you need on this.
This next piece was necessary for me, because part of my edge got a little too Velveeta and started to spark and spatter. And then crack.
So I amputated it's bottom, just above the crack.
About an inch of it. It looks better that way, trust me, and you'll fit those size sixes you picked up from Ross on a whim that one time but that always seemed one cookie too small to fit in without you spilling out the sides.
I used a cutoff blade with my skilsaw and just went for it. I did, however, try to avoid cutting in one spot for too long so as not to heat it up too high and ruin the heat treat. For whatever that's worth.
Wrapping It Up
I've kept you here too long. I'm sorry.
Let me 'splain. No there is too much; lemme sum up:
For appearances sake, I gave the splitter a good sanding with some 80, then with 120 and 220 grit sand paper. I didn't go for mirror finish, as I wanted it to have a more aged appearance. I also put it back in the oven at 500 degrees F, but just until I got a straw to brassy color (about 10 minutes in mine, but just keep an eye on it). I think it looks nice, and it wasn't hot enough to have messed with the microstructure.
I used the holes in the tang to mark the holes in the handle scales, and then drilled them to match.
I peened (at least I thought that was a word, and not a dirty one) out some aluminum wire until it fit the holes I'd drilled, and then cut two pieces for pins. For some reason I wanted to do two brass and two aluminum just for variety. The brass ones were simply brass screws that I had on hand.
I assembled the splitter dry just for sanding the scales down to fit the tang all around, and then used a five minute epoxy to assemble it permanently. The pins were dipped into it as well, and tapped into place. I then trimmed the pins to leave a quarter inch on either side, wiped up any excess epoxy, and then left it all well clamped for the night.
The next day, I unclamped everything and peened the pins (now rivets) flat. I thenrounded out the edges of the handle with some 120 and then 220 grit sandpaper, and oiled the handle with a beeswax/orange oil polish (Howards Feed-N-Wax).
The sharpening I left to the capable hands/preformed plastic guides of my little belt sander hand-tool. It has coarse, medium, and fine belts, and I just use them in order, switching as soon as I can feel a nice burr along the whole edge with my fingernail. Once that was complete, I used some leather gloves to strop the remaining burr into place.
And then I dangerously swung that baby like Lincoln's axe, Babe's bat, and Indiana's whip all rolled into one.
What do you think, not too bad, huh?
Oh, I also whipped up a Nicholson file knife while my fire pit was hot, following the fantastic instructions from casvandegoor here:
https://www.instructables.com/id/From-File-to-Knife-with-simple-tools/
And I picked up an old air compressor that someone was throwing out, and I'm converting it into a propane forge. That will be a future instructable if you're interested. I hope you're interested. I like you.