Author Topic: Draw knives questions  (Read 1373 times)

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Offline Mesophilic

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Draw knives questions
« on: March 19, 2018, 09:12:42 pm »
I've only been using one draw knife so far, I can't remember the brand but it has a 10" cutting edge length, single bevel hollow grind.

I've decided to add to the collection and I'm in the process of forging two 5" cutting edge draw knives.  One from 52100 and the other 1095,  goal is .25" thick and 2.5" wide, with the afore mentioned 5" long cutting edge.

1) What type of grinds do you guys prefer?  Flat grind, hollow,  or convexed? 

2) And what bevel angle do you prefer for the primary grind?

To me the hollow seems to bite deeper and aggressively, but as of now I have nothing to compare to.

Thanks.

Edited to add...if these work out I plan to make much longer versions in the 10 to 12 inch cutting edge length.
« Last Edit: March 19, 2018, 09:42:50 pm by dieselcheese »
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Offline willie

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Re: Draw knives questions
« Reply #1 on: March 19, 2018, 10:27:41 pm »
Quote
2) And what bevel angle do you prefer for the primary grind?

I reground the angle on mine to about 45, and like it a lot better, but I think it has a lot to do with the handle offset angle and how you prefer to work.  I use the shoulder? (not the cutting edge) of the bevel as a fulcrum to control the depth of bite, so it has something to do with how you hold it to work sweet.

Offline Badger

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Re: Draw knives questions
« Reply #2 on: March 20, 2018, 12:37:40 am »
   If you do make your own make sure you pay special attention to tempering and heat treating. A simple bring up to the right color and quench won't get it for a draw knife. A good draw knife will hold an edge over dozens of bows. Every one I have had knife maker friends make will not hold an edge through a single bow even though they look great. Very hard to beat a good commercial knife. I buy the old ones on e ebay and they are just the right hardness where a good quality file can sharpen them and they hold a very sharp edge for a very long time.

Offline vinemaplebows

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Re: Draw knives questions
« Reply #3 on: March 20, 2018, 12:45:53 am »
Ironic, I prefer my draw knife rather dull, seem to have more control. I also use mine up-side-down for less bite on the wood. Preferences I guess?:)
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Offline Mesophilic

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Re: Draw knives questions
« Reply #4 on: March 20, 2018, 01:34:46 am »
Every one I have had knife maker friends make will not hold an edge through a single bow even though they look great.

I'm  glad you brought this up.  I didnt even think about shallow hardening vs deep hardening for drawknives.  Its not that big of a deal and has ups and downs when making regular knives, hard edge but tough spine vs hard all the way through.

Looks like 1095 might not be ideal for long service life as it is a shallow hardening steel, perfect heat treat will be key to this one.  The 52100 should work great though,  as it is a deep hardening steel.

I think I'll take my chances with a brine/water quench on the 1095, see if that will cool it down fast enough to get a deeper hardening.
Trying is the first step to failure
-Homer Simpson-

Offline Badger

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Re: Draw knives questions
« Reply #5 on: March 20, 2018, 05:45:28 am »
Every one I have had knife maker friends make will not hold an edge through a single bow even though they look great.

I'm  glad you brought this up.  I didnt even think about shallow hardening vs deep hardening for drawknives.  Its not that big of a deal and has ups and downs when making regular knives, hard edge but tough spine vs hard all the way through.

Looks like 1095 might not be ideal for long service life as it is a shallow hardening steel, perfect heat treat will be key to this one.  The 52100 should work great though,  as it is a deep hardening steel.

     Your heat treating and tempering is about a 12 hour process.

I think I'll take my chances with a brine/water quench on the 1095, see if that will cool it down fast enough to get a deeper hardening.

Offline Dances with squirrels

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Re: Draw knives questions
« Reply #6 on: March 20, 2018, 08:01:54 am »
I do a flat grind on a 1" wide belt sander with progressively finer belts and then strop them with a leather belt on the same machine. I like em sharp
Straight wood may make a better bow, but crooked wood makes a better bowyer