The "Ask Nathan a question" thread

Lorien

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Preheat your oven 100 hotter than your austenitizing temperature

Wrap your blade in stainless foil. Double fold the seams and roll them. Place them where they won't interfere with the plate quench

Make a heat shroud out of foil to help reflect IR from the coils.

Once your oven is at temp for an hour, turn it off and put your work in. Place the heat shroud over the work.

Close the door and turn the oven on at your austenitizing temperature. If you've timed it right it will be pretty close so the exposed coils aren't on a long time burning your shit. Don't worry if you're a little over, the blade takes a few minutes to get up to temp.

Soak the correct amount of time for your application

Turn the oven off. Pull from the oven and quench between two metal plates to pull the heat out quickly. Ideally you want it under 100F in about a minute. This prevents the carbon from leaking back out of solution on the way down reducing certain carbides and maximizing strain energy to reduce RA. Don't worry about pearlite in A2 at this point. Any structures of that nature won't be formed here, it will be from decomposing retained austenite remaining when going into temper.

Once under 100 cut open the foil, hang it above the liquid nitrogen in a large dewer for enough time to get under -300F (an hour works). You can use dry ice in a pinch, you'll get most of the benefits at -100F

pull from cryo and warm until the frost starts to thaw. Clamp it straight and put it into temper. Temper two times (min) for an hour.

^ This is good basic HT for A2

Off the top of my head I'd guess for this application I might soak at 1725 for 30-40 minutes and my tempers might be 475 for a target hardness of around 58. You'll want to double check those numbers.


If you're just doing design development work you can skip a lot of that. Just get it hard and don't worry about a perfect HT.

by 'shroud' do you mean like a little tent?

and to double check; heat oven to 1825 and hold for an hour. Turn off, put knife in with shroud, turn back on to 1725 and soak for 30-40 minutes. Turn off, remove knife, plate quench, remove foil after a few minutes(?) and then put in freezer for an hour. Temper twice at 475 for an hour each

do I got it straight?
 

Nathan the Machinist

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by 'shroud' do you mean like a little tent?

and to double check; heat oven to 1825 and hold for an hour. Turn off, put knife in with shroud, turn back on to 1725 and soak for 30-40 minutes. Turn off, remove knife, plate quench, remove foil after a few minutes(?) and then put in freezer for an hour. Temper twice at 475 for an hour each

do I got it straight?

Yup. It sounds complicated but there's nothing to it.
 

Nathan the Machinist

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by 'shroud' do you mean like a little tent?

and to double check; heat oven to 1825 and hold for an hour. Turn off, put knife in with shroud, turn back on to 1725 and soak for 30-40 minutes. Turn off, remove knife, plate quench, remove foil after a few minutes(?) and then put in freezer for an hour. Temper twice at 475 for an hour each

do I got it straight?

And obviously, you want to wear some gloves and use tongs or pliers to put the work in and out. The radiant heat coming out of that oven when the door is open is legit.
 

Nathan the Machinist

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Nathan, I am way down towards the bottom of the pre-order list for the K18 (at least I got in). Using your best guess when will the last of the pre-orders ship?

I'm afraid to make estimates because I keep getting set back. Hopefully by the end of summer.
 

Nathan the Machinist

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Nathan what do you recommend to preserve ebonite scales?

Don't store it in direct sunlight and since it is a natural rubber product to keep oil off of it.

There are ebonite pens and wind instruments that are 100 years old and doing fine
 
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Casinostocks

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Nathan, I've been on a bushcraft and axe trip lately (all your fault BTW, as all my compulsive expenditure in things I don't really need but absolutely want is ALWAYS your fault) so with that caveat out of the way:

IIRC there were some discussions in the past about some dedicated bushcraft CPK knife but knowing your preferences for not wanting to go below a certain stock thickness, seems that you never warmed up too much to the idea. My Q is not really a Q but just to resurrect the idea that something thinner in the exact mold of the ultra sexy OGFK with the pry bar at the end is not too daft an idea. Think on it as you charm Jo into accepting that CPK-Axe project :D

ETA: another thing which didn't exactly titillate was the Scandi grind thingie.
 

Nathan the Machinist

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Edit: ...whoops, wrong thread....
 
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Lorien

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Nathan, I have a question for you;
you've seen a lot of guy's hammers, and I was wondering if you'd rate mine?
abnikcd.jpg

;)
 
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