flapjack

Hardening / Tempering Drawknife

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Hey everyone, first post here.

just found this site and its incredible how much info is one here.

Ive just finished making a drawknife ( ill post a pic soon) and ive hardened it and tempered it already but i have some questions about how i could do it better. It is made with a coil spring from a train. and my quenching solution is used motor oil, which i understand to not be the best.

When hardening it i had a difficult time keeping it from curving or warping.  it took me 3 attempts after  it to get it to harden and maintain a (reasonably) straight edge. ( its still a bit wiggly)

I then made a little torch using a block with a hole in it over my forge to temper the blade. This worked fairly well.

Im wondering how other folks harden / temper their drawknives here without ovens?

 

Thanks in advance!

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no oven? How do you  cook food?

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Where are you at?  I use tempering tongs.

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1 hour ago, Steve Sells said:

no oven? How do you  cook food?

What ... you guys dont cook on your forge?;)

I live in Hazelton which is northern BC.

So with tempering tongs, do you have a pair with heated metal the length of your drawknife ? or are you moving it back and forth?

 

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Well my wife certainly wouldn't let me temper stuff quenched in Motor oil in *her* oven! (Again!!!!!)

You can move them or just make a set the size you need, they are not difficult to make.  Mine is just a couple of bars arc welded to a set of pull-offs

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Welcome aboard Flapjack, glad to have you. We're blacksmiths not memory brainiaks, we aren't going to remember where you are a couple posts down this thread, let alone next time you post. If you'll put your general location in the header it's right there so we can go back to thinking about fire, smooshing steel and building things. That and you might be surprised how many of the gang live within visiting distance.

I use a soft flame on my oxy propane torch to do differential tempers on the RARE occasions I make a blade. I've done similar to what you show in the picture but used fire brick. I was a lot happier heating a heavy bar of steel and laying the blade's spine on it.

My shop has a toaster oven for hot lunches, wax burn out, and tempering when necessary. I picked it up at a local church rummage sale for $5.00.

I don't know how a shop can do anything efficiently without a toaster oven and dorm fridges. Seriously, I have to walk more than 100' to the house for a hot lunch or cold beverage! Intolerable I tell you!

Frosty The Lucky.

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Alright location is in profile now. Should show where I am.

 

Here's some pics finally. This is my 3rd draw knife. Just can't seem to get the cutting edge straight enough.

 

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Remember Moxon's suggestion in "Mechanick Exercises" published in 1703? "He that will a good Edge win,  Must Forge thick and Grind thin."

Is it the belly in the blade you are having issues with?

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what a great quote!, that might explain my the issue im having. i have forged it fairly thin.

it is the cutting edge that im having issues with. looking down it length wise, is does a little "S" curving.

Thanks!

 

my next step is handles.  My previous drawknives, I made a wooden handle and then threaded the tang and fastened it all with a nut. Its not as smooth as id like though.  I was thinking either having the tang poke through the end of the handle and then slipping a brass washer over it then peening it tight, or just epoxy the tang in a dead end hole in the handle.

how have you folks done it?

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you can poke the tang through and then bend it over a copper washer, or peen it (rivet it) over a washer or if you are using a handle with a ferrule just jam it into the handle.

 re tempering , you will get much better results from a kitchen oven than any torch, forge or other un regulated heat source., temper colours are not a very exact way of tempering steel)....canola oil  (rape seed in the UK) works well as a quenchant .

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Kitchen oven for the blade edge, propane torch (or forge) to draw the handles back further and tempering tongs or torch to deaw the spine of the drawknife back more than the edge---done with the edge sitting in water of course.

S in edge; how thick was the edge when you quenched it?  You see in knifemaking it suggested that the edge be at least the thickness of a US dime.

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Ive got it reasonably straight now. tempered the cutting edge on the forge. used a torch to temper the spine while cutting edge sat in water. So far so good. now im waiting for the right size copper pipe to show up at the dump for the ferrules. Using Coastal Yew wood for the handles.

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Make friends with a plumber?  I've used copper pipe to make Habaki for knives; but you need the exact size to do a "no solder/weld" one. One thing I learned is that they make repair pipe that will just slide over the "normal" pipe with a close enough fit that you can sweat them together.  Usually sold in short lengths at a premium. But it can be handy to have when you are building up a collection of pieces to use for smithing projects.

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