New knife maker looking for assistance with finishing a knife.

B

BadKnife

Joined
Dec 28, 2015
Messages
14
Background:
2 months knife making experience
no craftsmanship experience
O1 tool steel
1x30 bench sander free hand
own heat treating (propane forge) in garage with motor oil.
Hand sanding before heat treat to 220grit.

My issue is this:
I am able to get the knife blade to look awesome before heat treatment. Once I heat treat in the self made propane forge and quench it, the blade develops scales and discolouration. Which I understand is normal. However, when I try to use my bench sander the bevel line is not very even. I can get a nice bevel with 80 grit but once I move to 220 grit after heat treat the bevel gets wavy and spotty. I think it may be that I am not steady enough.

In order to get the bevel nice and clean I have to spend hours hand sanding after heat treat. This creates a nice bevel/blade but I am aiming for a fresh clean blade with a grind pattern on the bevel so there is a distinct separation. I like that look and I am struggling to achieve this.

I have considered a jig for the bench sander but the work surface to pretty small on the 1x30. As I mentioned I do not have a lot of tools or experience with this stuff. I have read articles and watched hours and hours of videos.

Any advice and assistance is appreciated.

Preheat Treat:
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Post finish, blade not sharpened as I too afraid to destroy the bevel

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You already have the answer, not steady enough. Any small variation with an 80 grit aren't seen because of how much material it's removing. With higher grit belts tis just smearing and rolling instead of cutting. Try going to a 120-150 before the 220. Looks pretty good though!
 
You should sand to at least 400 grit before HT. Also check out Fred Rowes bubble jig it will help you get the hang of grinding. Also what Matt R said about changing grits, you should double your grit when you change I think 80 to 220 is too big of a jump.
 
BadKnife said:
In order to get the bevel nice and clean I have to spend hours hand sanding after heat treat. This creates a nice bevel/blade but I am aiming for a fresh clean blade with a grind pattern on the bevel so there is a distinct separation. I like that look and I am struggling to achieve this.

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I know the struggle. I don't have a 2 x72 either yet. Time spent straightening grinds by hand is time well spent I believe. draw filing annealed steel works great at removing large quantities of metal and if you dont pull down on the file it will even your bevel out.


I am pretty good with tools. Knifemaking is still humbling work to learn.
 
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I don't grind the bevels till after heat treat. But I also have a variable speed 2x72. 1x30 belts wear extremely fast as you only have 1" width to work with. On 80g you are going to get even surfaces you won't see on that rough grit, they only appear after moving up. You also need a sturdy platen as well.

I would suggest not grinding until after heat treat, if you are going to go this route, most likely you got a lot of uneven surfaces.

You can make a nice knife without a big grinder, it just takes a lot longer...
 
Grinding is the tricky part, that's why most new makers start with files. Using a belt grinder can save you a lot of time or create a lot of extra work for you. What your wanting is one flat even grind from plunge to tip not a bunch of passes making up the edge bevel. Sometimes hard to tell with course grits as it all Blends together but I'm with the other guys, bring up the grit finish by hand befor hear treating. I would draw file the edge bevel flat and then use sand paper on blocks and remove the file marks. Then heat treat, you can try soaking in vinager over night to remove the scale. Then back to the sanding blocks.
 
Thank you for the input. I will try that advice on my next knife.
Nice forum here by the way.
 
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