Amount of time to grind bevels?

S

SamaraVolk

Joined
Apr 17, 2014
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93
Again I've been trying to improve my grinds and seem to be making little progress. I am thinking I may be rushing the process for what I want to achieve. How long does it take you guys to grind both sides of a knife? Just a rough estimate. Let's say:

1) Pre or post heat treat?
2) Flat grind to where you are ok with your plunges
3) Using only your first belt. Example: 36 grit to get the desired shape
4) My 2x72 is 110V and 1 HP motor. I get around 6000FPM due to the size of the drive wheel.
 
It's hard to say the exact time when I do pre and post heat treat grinding, since the time spent is split between two sessions. I just finished a 7" long blade (3/16" thick" fighter in heat treated AEB-L at 60-61RC). All grinding was done post heat treat. (except profiling of course). It took 45 minutes from no bevels to completely done. I would say it took 15 minutes on the 36 grit to remove most of the material. From there, a lot of belts to progress up to a cork belt with compound. My typical progression is: 36, 60, 120, A165, A100, A45, A30, Cork
 
Kevin McGovern said:
It's hard to say the exact time when I do pre and post heat treat grinding, since the time spent is split between two sessions. I just finished a 7" long blade (3/16" thick" fighter in heat treated AEB-L at 60-61RC). All grinding was done post heat treat. (except profiling of course). It took 45 minutes from no bevels to completely done. I would say it took 15 minutes on the 36 grit to remove most of the material. From there, a lot of belts to progress up to a cork belt with compound. My typical progression is: 36, 60, 120, A165, A100, A45, A30, Cork
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Man that is fast
 
like Kevin said, about 15 mins for that heavy grit belt
another 30-45 depending on blade and finish desired,

it takes like 30 blades to get to a reasonable speed.
 
How many blades have you ground total? quicker times come with experience and practice.
 
Depends on the size of the knife and the level of finish more than anything else. Back 8 or 9 years ago, I heard that guys making and selling scandi grind Woodlore style bushcraft lives in the UK for good money could grind out up to 20 blades in one sitting from PG O1 and have them ready for HT by the end of the day. I contrast that with the amount of time it takes to grind and finish say a big bowie or large kitchen knife with a hand rubbed finish. o_O
 
SBuzek said:
How many blades have you ground total? quicker times come with experience and practice.
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I've probably made about 60 blades total. I can grind fairly fast but not if I want a really nice even plunge line on both sides.
 
using a 60 and 120 grit belt pre heat treat, maybe 10 minutes for a single grind hunter with an .030" edge.
 
SamaraVolk said:
I've probably made about 60 blades total. I can grind fairly fast but not if I want a really nice even plunge line on both sides.
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I never grind the final plunge while hogging off material. I start 1/4" in front of where I wan the plunge. I use a 50 grit belt and take it to about 85% where I want the grind. Put on a 100 grit belt on the grinder and a file guide on the blade then start the plunge and work it into the grind and then finish where I want the grind.

Then to a 220 grit belt, from there is just a matter of removing scratches and not moving the grind. Where you leave off your grit is up to you.
 
SamaraVolk, we're probably at about the same level of experience. I'm in awe of the craftsman who can fast-grind (or slow-grind, for that matter) their blades with perfect control. I think it just takes time for your eyes and hands to work together. I'll never been an excellent knife maker (don't have it in me), but I aspire to be a better one ... and faster too. Spent about two hours today on an 8" chef's knife. About two hours from blank to final (not finished) bevel. That's pretty good for me!
 
SamaraVolk said:
I've probably made about 60 blades total. I can grind fairly fast but not if I want a really nice even plunge line on both sides.
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Unless you are running a production shop don't really worry about speed. Getting a good clean grind is worth a lot more than shaving 15 minuets off your time. I don't care how long it takes me to grind a blade as long as when I'm done, hand sanding goes quickly when you get a good finish off the grinder.
 
Devin is spot on. Im currently working on a batch of 4 3" drop points with flat grinds. On 1/8" A2 grinding entirely after heat treat roughing them all in to 90% with 36 grit took about 20 minutes. Finishing then out the rest of the way (ground to 240, scotchbright, and finished on grease less compound) took another hour and a half or so.

I'm fairly light handed at the grinder, and consider myself on the slow side. It just takes lots of practice.
I also find hollow grinding much faster and easier for me.
 
AVigil said:
I never grind the final plunge while hogging off material. I start 1/4" in front of where I wan the plunge. I use a 50 grit belt and take it to about 85% where I want the grind. Put on a 100 grit belt on the grinder and a file guide on the blade then start the plunge and work it into the grind and then finish where I want the grind.

Then to a 220 grit belt, from there is just a matter of removing scratches and not moving the grind. Where you leave off your grit is up to you.
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How do you work a plunge back? I have heard many makers say this and for me, unless I use a file, once the plunge is there, its there.
 
The barefoot boy said:
How do you work a plunge back? I have heard many makers say this and for me, unless I use a file, once the plunge is there, its there.
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Grind your bevel 1/4" ahead of where you want it.

Then go back a 1/16" of and inch and move the plunge back, then move 1/16" back again and work the plunge back again.

Constantly checking that the edge on center and check the top of the plunge as it merges to the existing grind.

Keep doing that until the plunge is where you want it, on center, radius equal both sides and the top of the plunge same on both sides at the same height.

Then clean up with your belt of choice. I like Hermes 346 and Gators for plunge work.
 
As long as it takes. Don't worry about anyone or anything else. I put on hearing protection ear muffs so it's just completely silent and just get in the zone.
 
The barefoot boy said:
How do you work a plunge back? I have heard many makers say this and for me, unless I use a file, once the plunge is there, its there.
Click to expand...

Been meaning to post a picture of this but I haven't been grinding because of the cold. But like Adam described, here is a rough ground blade. When this is heat treated and finish ground, I'll walk the plunge back to meed the "L" where the edge come out from the ricasso. But not until then.

o1SEKX2.jpg

3RA9Dzs.jpg
 
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