How to Make a Draw Knife
Intro: How to Make a Draw Knife
This instructable demonstrates annealing steal in order to make, in this case, a draw knife from an old file. This process could be used to make just about any kind of cutting tool from any old peice of hardened steel.
In another instructable I recommended these instructions
http://www.woodworkersworkshop.com/cached_files/33092_files/
and then realized I'd never followed them completely. On doing so I have come to the conclusion that they're as usefull as I thought and would continue to recommend them as a simple way to heat treat hardened steel.
In another instructable I recommended these instructions
http://www.woodworkersworkshop.com/cached_files/33092_files/
and then realized I'd never followed them completely. On doing so I have come to the conclusion that they're as usefull as I thought and would continue to recommend them as a simple way to heat treat hardened steel.
STEP 1: Know What You Need Before You Need It.
Don't take on this project lightly, although this really is rather simple you will need quite a few things and it will take a couple days to finish. And don't get too discouraged if it doesn't work out just right the first time.
Stuff you need:
- about 12 fire bricks (they're usually kinda yellow)
DO NOT USE ANY OTHER TYPE OF BRICKS!
THEY EXPLODE!!
- charcoal, get a big bag use the extra for a barbeque
- lighter fluid, it just makes things easier
- an old file, don't use a new one they're usually just some
crappy soft metal covered by a harder one
- a coarse metal file, a grinder will help speed things along
- a cheap hair dryer, you need something to force air into
the "oven" (be careful if you borrow this, I've killed at
least one for sure) you'll need to find a way to secure this
in front of the oven
- a pipe long enough to reach front to back of the oven, 1/2"
steel is best but I used an old aluminum tent pole and it's
lasted through several heatings
- a pair of long pliers or tongs to handle the metal while
heating
- a small sledgehammer, just in case
- sandpaper, at least 80 and 100, the higher you go the better
- a breadpan, or other suitible metal container
- oil to put in the breadpan, I used 30 weight motor oil but
I've read that olive oil works rather well
- some peices of hardwood for the handles, I had some walnut
from an ice strom a few years ago. hickory, maple, oak, etc.
will work
- epoxy for the handles, preferably the slow set type. I've used
gorilla glue and it worked but epoxy's by far superior
- Acetone (a.k.a. fingernail polish remover) you don't need much
- a saw to shape the handles, wood rasps help if you've got them
- an oven, or whatever you can consistantly heat to 450degrees
F. for an hour
- a knife, chisle, or gouge to cut grooves in the handles
- a finish for the handles, I used linseed oil
- a shaprening stone -not completely necessairy
read through the steps carefully, I probablly left something out. Sorry this list is so random I wrote stuff as I remembered it.
Stuff you need:
- about 12 fire bricks (they're usually kinda yellow)
DO NOT USE ANY OTHER TYPE OF BRICKS!
THEY EXPLODE!!
- charcoal, get a big bag use the extra for a barbeque
- lighter fluid, it just makes things easier
- an old file, don't use a new one they're usually just some
crappy soft metal covered by a harder one
- a coarse metal file, a grinder will help speed things along
- a cheap hair dryer, you need something to force air into
the "oven" (be careful if you borrow this, I've killed at
least one for sure) you'll need to find a way to secure this
in front of the oven
- a pipe long enough to reach front to back of the oven, 1/2"
steel is best but I used an old aluminum tent pole and it's
lasted through several heatings
- a pair of long pliers or tongs to handle the metal while
heating
- a small sledgehammer, just in case
- sandpaper, at least 80 and 100, the higher you go the better
- a breadpan, or other suitible metal container
- oil to put in the breadpan, I used 30 weight motor oil but
I've read that olive oil works rather well
- some peices of hardwood for the handles, I had some walnut
from an ice strom a few years ago. hickory, maple, oak, etc.
will work
- epoxy for the handles, preferably the slow set type. I've used
gorilla glue and it worked but epoxy's by far superior
- Acetone (a.k.a. fingernail polish remover) you don't need much
- a saw to shape the handles, wood rasps help if you've got them
- an oven, or whatever you can consistantly heat to 450degrees
F. for an hour
- a knife, chisle, or gouge to cut grooves in the handles
- a finish for the handles, I used linseed oil
- a shaprening stone -not completely necessairy
read through the steps carefully, I probablly left something out. Sorry this list is so random I wrote stuff as I remembered it.
STEP 2: Start a Fire
First make your oven with the fire bricks.
Again let me stress the importance of using bricks specifically made and tempored for use with fire. Other brick types are porous and often contain air pockets, which when heated cause the brick to explode, sending hot brick fragments, burning coals, and your red hot peice of metal flying in all directions.
Make the bottom with four bricks, use two for each side laid edge down on the bottom bricks. use one more for the back, same as the sides. The top will be put on after the fire is started, lay the remaining three bricks on the sides, make sure to leave a gap of about 1/2" at the back of the oven. The pipe goes in the bottom of the oven centered and about an inch from the back, this helps evenly distribute the airflow.
Once you have the charcoal burning, make sure the coals at the front are burning well or the fire won't heat evenly, go ahead and put the top bricks in place and turn on the blowdrier.
Once it gets hot, glowing brightly, put some more charcoal in.
Again let me stress the importance of using bricks specifically made and tempored for use with fire. Other brick types are porous and often contain air pockets, which when heated cause the brick to explode, sending hot brick fragments, burning coals, and your red hot peice of metal flying in all directions.
Make the bottom with four bricks, use two for each side laid edge down on the bottom bricks. use one more for the back, same as the sides. The top will be put on after the fire is started, lay the remaining three bricks on the sides, make sure to leave a gap of about 1/2" at the back of the oven. The pipe goes in the bottom of the oven centered and about an inch from the back, this helps evenly distribute the airflow.
Once you have the charcoal burning, make sure the coals at the front are burning well or the fire won't heat evenly, go ahead and put the top bricks in place and turn on the blowdrier.
Once it gets hot, glowing brightly, put some more charcoal in.
STEP 3: Annealing
In this step you're going to take the hardness out of the file to make it easier to work with.
Now that you've got the oven well heated, take off one or two top bricks (I suggest using thick gloves like those for welding) and put the file into the center of the coals, then add some more charcoal on top of the file.
Watch the file, when it turns bright red turn off the hairdrier and let the fire burn out. Leave the file in the oven until it is cool enough to pick up with your hand. This will take hours.
If the file comes out warped, the oven cooled unevenly but it's an easy fix. Start up another fire just as before. This time when the file turns an even red pluck it out and straighten it with that small sledgehammer I suggested you have. You don't have too much time to do this, if it cools and gets too hard before you get it straight throw it back into the fire and let it get red again. When you're done straightening it, turn off the hairdrier and put the file back into the oven to cool.
Now that you've got the oven well heated, take off one or two top bricks (I suggest using thick gloves like those for welding) and put the file into the center of the coals, then add some more charcoal on top of the file.
Watch the file, when it turns bright red turn off the hairdrier and let the fire burn out. Leave the file in the oven until it is cool enough to pick up with your hand. This will take hours.
If the file comes out warped, the oven cooled unevenly but it's an easy fix. Start up another fire just as before. This time when the file turns an even red pluck it out and straighten it with that small sledgehammer I suggested you have. You don't have too much time to do this, if it cools and gets too hard before you get it straight throw it back into the fire and let it get red again. When you're done straightening it, turn off the hairdrier and put the file back into the oven to cool.
STEP 4: Transform That Peice of Metal
First mark out and cut the file so both ends are the same.
I used a hand grinder but a bench grinder or hacksaw or even a metal file will work.
Second, if you had to straighten out the file you'll probablly want to get rid of the dimples that were made by the hammer. Use the grinder or file to grind down the surface until you can't tell where the dimples are. Don't worry about removing the grooves from the old file, they are deeper than you'd think and give your knife some character.
After that is done, if it was needed, you'll rough out the cutting area. Twenty to twenty-five degrees is a good angle for the knife edge. You can use the grinder to remove material initally but you should use a coarse metal file to make sure the edge is uniform in angle and flat.
Once the knife edge is roughed out, though it may be quite sharp now, sand the whole thing. Start with a coarse grit like 60 or 80 and work up to at least 150 for a smooth looking tool. You could go all the way up to 600grit if you wanted to use it as a mirror, but that's up to you.
I used a hand grinder but a bench grinder or hacksaw or even a metal file will work.
Second, if you had to straighten out the file you'll probablly want to get rid of the dimples that were made by the hammer. Use the grinder or file to grind down the surface until you can't tell where the dimples are. Don't worry about removing the grooves from the old file, they are deeper than you'd think and give your knife some character.
After that is done, if it was needed, you'll rough out the cutting area. Twenty to twenty-five degrees is a good angle for the knife edge. You can use the grinder to remove material initally but you should use a coarse metal file to make sure the edge is uniform in angle and flat.
Once the knife edge is roughed out, though it may be quite sharp now, sand the whole thing. Start with a coarse grit like 60 or 80 and work up to at least 150 for a smooth looking tool. You could go all the way up to 600grit if you wanted to use it as a mirror, but that's up to you.
STEP 5: Hardening
To reharden your knife you're going to fire it again and then quench it in oil.
Heat the oven as before and watch the knife. It will go through stages of dark red colors and then become a bright cherry red. When it reaches this take it quickly and dip it in back first, so the last part to go in is the knife edge. Dip it in and out of the oil about ten times and then leave it in the oil until cool enough to handle.
Make sure the oil is close to the oven so you don't loose any heat in the transfer.
After it cools clean it and sand it back to a bright finish. Once sanded wipe it down and clean it with acetone.
Heat the oven as before and watch the knife. It will go through stages of dark red colors and then become a bright cherry red. When it reaches this take it quickly and dip it in back first, so the last part to go in is the knife edge. Dip it in and out of the oil about ten times and then leave it in the oil until cool enough to handle.
Make sure the oil is close to the oven so you don't loose any heat in the transfer.
After it cools clean it and sand it back to a bright finish. Once sanded wipe it down and clean it with acetone.
STEP 6: Tempering
This step will take the brittleness out of the knife, keeping the edge sharp.
The easiest way to do this is with a conventional oven.
Set the oven at 425degrees F.
Once up to 425 place the knife in the center of the oven, cutting edge up. This can be easily done by using some wire (a wire coat hanger works well) wrapped around the ends and formed into hooks at the other to hang from the oven rack.
Leave the knife in the oven at 425 for an hour and fifteen minutes. Then turn the oven off but leave the knife in for another thrity minutes. After that take it out and let it air cool somewhere.
The cutting area after this heating should be a yellowish straw color.
Once tempered finish the knife by sharpening it on a stone. I got mine for about $15 from a hardware store.
The easiest way to do this is with a conventional oven.
Set the oven at 425degrees F.
Once up to 425 place the knife in the center of the oven, cutting edge up. This can be easily done by using some wire (a wire coat hanger works well) wrapped around the ends and formed into hooks at the other to hang from the oven rack.
Leave the knife in the oven at 425 for an hour and fifteen minutes. Then turn the oven off but leave the knife in for another thrity minutes. After that take it out and let it air cool somewhere.
The cutting area after this heating should be a yellowish straw color.
Once tempered finish the knife by sharpening it on a stone. I got mine for about $15 from a hardware store.
STEP 7: Handles
To finish off the project add your handles.
Cut four small slabs the length you want your handles and half the thickness. Use a knife, chisel, or gouge to make a groove in each peice. A trick I found usefull is to cut the groove in one slap half the thickness of the file and so it is a good fit. Then hold the two peices together and pour sawdust down into the groove. place this on your workbench and carefully lift off the peice with the groove. outline the sawdust with a pencil and check to make sure both peices are the same, then just cut out where you marked.
Once the grooves are finished, epoxy the handles to the knife. Clean the ends with acetone again before you glue them. As you can see in the pictures I used gorilla glue for this project. It really doesn't work well for this, but it does work. Actually one handle didn't set well and I ended up using epoxy to reattach it. So do yourself a favor and go to the hardware store and get epoxy specifically for tool handles.
Once the handles are on and the epoxy is completely set shape the handles with a knife, a wood rasp is also good for this process. Watch out for the knife, it's sharp. Once you get the handles shaped sand them and then finish them. I would suggest using tung oil or linseed oil instead of polyethylene, but that's just a personal preferance.
Remember to oil you knife occasoinally to prevent rust.
Cut four small slabs the length you want your handles and half the thickness. Use a knife, chisel, or gouge to make a groove in each peice. A trick I found usefull is to cut the groove in one slap half the thickness of the file and so it is a good fit. Then hold the two peices together and pour sawdust down into the groove. place this on your workbench and carefully lift off the peice with the groove. outline the sawdust with a pencil and check to make sure both peices are the same, then just cut out where you marked.
Once the grooves are finished, epoxy the handles to the knife. Clean the ends with acetone again before you glue them. As you can see in the pictures I used gorilla glue for this project. It really doesn't work well for this, but it does work. Actually one handle didn't set well and I ended up using epoxy to reattach it. So do yourself a favor and go to the hardware store and get epoxy specifically for tool handles.
Once the handles are on and the epoxy is completely set shape the handles with a knife, a wood rasp is also good for this process. Watch out for the knife, it's sharp. Once you get the handles shaped sand them and then finish them. I would suggest using tung oil or linseed oil instead of polyethylene, but that's just a personal preferance.
Remember to oil you knife occasoinally to prevent rust.
41 Comments
Ray from RI 11 years ago
A real draw knife technically has tangs that are at right angle to the length of the blade... With so many draw knives cheaply available on the used tool market you do not really need to make one.
However push/pull shave/knife are not common and are a good tool to have or add to your collection. Most often the blades on these shaves/knifes is at best 4 to 6 inshed and they are most often used for 3D wood carvings/statues.
Been collecting both antique tools and books on tools for over 30 years and this is a good project to show how to make a push/pull knife....!!!
Often the most common on on the market for sale is a Moria Swedish push'/pull knife...!
curvy77 12 years ago
cojonc 12 years ago
As a former shipwright I would like to make a comment on using epoxies as wood glue. Epoxy is different from other glues and must be treated very differently. For one, epoxy REQUIRES A MUCH WIDER GLUE LINE TO BE STRONG, and may also need a filler for hardware bonding (as in the handles)
Yellow wood glue is absorbed further into the wood than epoxy, and requires a correct clamping pressure to be strong. Too much pressure and it looses strength because the glue joint becomes too thin.
Epoxy on the other hand requires a wide glue joint. If you clamp an epoxy joint tightly, squeezing much of the glue out, when you test it later, it just might separate far easier than expected. I have made poor joints during epoxy testing where two pieces of oak were separated with less than 20 lbs of pull!
The strongest wood joints with epoxy are intentionally roughened before gluing. I will often use a rough rotary file everywhere but the edges of the wood--on both surfaces--before applying the epoxy. Then when clamping, use only the minimum pressure needed to keep the joint aligned until the epoxy cures.
Usually, the rougher the contacting surfaces, the better. On very dense wood, epoxy penetration into wood pores is minimal, so I do not recommend it unless the wood is extremely roughened and the epoxy thickened. The fibers must be raised as the epoxy will basically grip only them. Think microscopically to get an idea of what is happening in extremely dense species.
Epoxies usually require a thickening additive to reach ultimate bonding strength. There are many additives available and each has been engineered for a specific use. I often used West System or Shell Epon Epoxy mixed with with colloidal silica for the strongest hardware bonding and never had a failure--at least nothing was ever reported. Additionally, thickening the epoxy can provide better control against initial sagging or running. Here is the West system URL ( http://www.westsystem.com/ss/ )
There are many different varieties of epoxy and most are decent. However, it is always advisable to read the manufacturers recommendations for the glue joint as well as the species of wood you are using. As example of the problems encountered are woods that retain large amounts of oils even after curing, and do not respond well to normal gluing.
If it's a joint that you need to count on for years of use against heavy strains (as in attaching handles to steel) consult the mfg's representatives directly! Seriously, this is important. Epoxy is no miracle glue, and it will not perform perfectly just by slopping some on. Many people do not realize this.
A friend of mine was nearly killed when the head of an axe, swung by a friend, separated mid-swing and caught him in the throat, crushing his trachea. The person who attached the head, simply slopped in some 5 minute epoxy and pounded the head on tight again. The glue shrank, pulling away, and left the head hanging by nearly nothing. It separated on the first use. I have done similarly when I first began using epoxy. We are all guilty of ignorance in one form or another.
Additionally, I absolutely DO NOT recommend the "quick curing" epoxies for critical joints as they are brittle glues and can fail from cracking, shrinking, and debonding unexpectadly. Fast curing epoxies are considerably weaker than the long cure types. Consider those quick set types useful for gluing non essential items around the home and little more.
I have used many varieties with equal success. I think it is more what you become use to than much else--as long as it is the very slow cure type.
There are also water based epoxies and they often got bad press from people thinking them somewhat similar to the early latex paints, but they are actually very fine epoxies.
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Now, on other points, I am using your instructions to fashion a draw knife to replace a 21 inch draw knife I lost. I need to fashion some pine logs to build a Texas style log based patio enclosure. I will be curving it in two directions and welding on some handle attachments.
Good info on the heat treating. I have never attempted serious heat treating and your info will come in handy Thanks!
the mechanical engineer 14 years ago
red-king 13 years ago
rbentley1 12 years ago
I'm not trying to hate though, I"m just curious.
absolutekold 13 years ago
eli_avery 13 years ago
Ron-Ray 14 years ago
notjustsomeone 14 years ago
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