Repairing tip damage on gifted Spyderco

A

Arch.Chaos

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Oct 1, 2007
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knife.jpeg

My brother found a beautiful Spyderco as a b-day present for me for all of 20 bucks. I love it!

Now to my question: looking at the tip, it looks like it was ground and got very hot - do y'all think it got hot enough to ruin the heat treat?
tip.jpeg


As for the chip in the edge, I was thinking I could try to sharpen it like a small serration to avoid taking off too much metal.

Thoughts? It's my first CPM S45VN knife; for sharpening I've got a big, coarse double-sided DMT stone and Spyderco ceramic benchstones and rods.

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Good advice from Bill D. above.^ :thumbsup:

In just a few normal sharpenings down the road, both the chipped portion and the (possibly) heat-damaged steel at the tip will likely be worked out. That's the most straightforward approach and the simplest as well, with only the necessary minimum amount of steel removed to fix the issues.

If the possible heat damage is worse than assumed and extends more deeply through the tip end of the blade, then later maybe something else might be done to grind it away by altering the tip profile. But no need to do that right away until you're sure it's necessary. You'll get a sense of how damaged (or not) the tip is by watching how it holds up in use. If it breaks or chips or otherwise fails to hold a durable edge, that's a sign there's some likely damage to the temper. If it stays strong and takes & holds a good edge, then nothing to worry about.
 
I’d just give it a good sharpening, like a full burr forming sharpening. If the tip is overheated, it’s probably not enough to make it worth grinding the burned metal off and forming a new one. If you break the tip in normal use, then you know it was damaged enough to be a problem, and you have to grind a new tip anyway.
 
The yellow and purple indicate the top was heated. For carbon steels, the purple would likely be too hot. However it is very small and this is stainless steel. That means two things.

The tempering temperatures for such stainless steels are or can be very different from carbon steels. The other thing is the colors come from surface oxides. Stainless steels are specifically meant to resist oxidation. The temperatures the oxides form as far as I know are not well catalogued for stainless steels. They are at least documented for carbon steels. Certain colors form during certain temperature ranges.

So, all that means we are in the dark as far as the temperatures the tip reached. It also means this blade is more resistant to temperature than normal carbon steels so it may not matter. Your plan to sharpen and use seems a good one. At worst the purple part of the tip may break off and have to be reformed during regular sharpening or ground to reshape it.
 
Interesting! I love learning the little details, or lack thereof; I still remember the day I discovered links to the Science of Sharp blog posts here.

As for the knife, it came out well - about 30-45 minutes on both sides of the coarse DMT plate, then 15 minutes on the Spyderco brown benchstone. Still toothy, but it push cuts paper.
new-edge.jpeg


And this is the new edge around the chip (my brother saw this and said, "It looks like boobs", which I'll admit is not something that entered my mind...):
nick-after-sharpening.jpeg


I appreciate the advice and sharing of knowledge. I'm excited to get out and use this knife.
 
Your hand sharpening is very consistent. I have been very effective hand sharpening, but I will admit that I have not spent time admiring how consistent I am (or am not). Looks nice!
 
pitonyak said:
Your hand sharpening is very consistent. I have been very effective hand sharpening, but I will admit that I have not spent time admiring how consistent I am (or am not). Looks nice!
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Thank you, that’s kind of you to say! I’ve come to really enjoy sharpening; this winter has been terrible for snow, so I’ve put in a lot of hours at the stones – perhaps it’s showing. One can hope :)
 
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