Coarse Grit Sharpening

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old4570

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While doing some Dual Grit Sharpening tests , I threw in a 240/240 grit test on the IXL Lock Back because the Dual Grit performance increase was - Lack Luster !
Steels being steels , not all steels will respond the same to the way the knife is sharpened . And to be honest the steel on the IXL . might be that cheap Japanese stuff they were famous for quite a few decades ago ! ( Yeah , that happened )
Anyways , the IXL responded to the 240/240 edge like a rising phoenix !

IXL ( Japan ) Lock Back from ? ( 80's maybe ) These were cheap as chips back in the day .
Guided edge - 200 Roll
80 grit grind ( Toothy ) 350
Dual Grit 240/800 ... 450
Dual Grit 400/800 ...200Roll
240/240 ... 900 ( No Fail )

Now 900 slices is nothing to sneeze at , it's the stomping ground for Super Steel .
So what the heck happened ? How does a Budget steel step on Superman's Cape ? ( I mean supersteels turf )

Brisa Hiker 95 ( Disappointing Knife - for me - I'm sure everyone else got a good one )

https://www.bladeforums.com/threads/brisa-hiker-95.1903594/ Brisa Hiker 95 12c27n

I put a dual grit edge on this knife and ...
Previously - a 150 to 200 roller
Dual Grit - 400 at which point I got distracted by the blood ( spine was wearing a hole in my finger ) , and forgot to test the edge .. Failed at 450 .. Or maybe 400 ? I don't know Cos I got distracted by the blood !
Lets call it 400 !
240/240 - Steel is 12c27n and rolls like an Olympic champion ! Result was a 500 Fail with what appears to be no roll ..

So if we forget about dual grit , we have gone from 200 to 500 .. Only 150% more ..
And the edge was no where near as toothy as the IXL .. ( Better steel I guess )
Yeah , Diamond Cuts deeper into inferior steel and more shallow into superior steel .. Affecting how toothy the steel will feel .
Bottom line is , Coarse Grit looks to do something ..
Is it the opposite of dual grit ?
Dual Grit - The better the steel , the more slices ( longer lasting edge )
Coarse Grit - The worse the steel , the more slices ( longer lasting edge )
This testing will be interesting ... I have lots of disappointing knives .. More testing to come !

 
I didn't watch the video......Are you sharpening on a pedestal bench grinder?
 
Mora Garberg > https://www.bladeforums.com/threads/mora-garberg.1920483/

A 150 Roller ...
I just spent about an hour with 120 grit diamond re profiling the scandi edge .
Then I cleaned it up with 320 grit diamond .
I took the blade back to true Scandi ..
So 120 grit cleaned up with 320 grit .. The edge is very hacksaw like , with a few spots woodsaw like ( that 120 grit )
Will , coarse grit sharpening save the Garberg ? ( 150 edge roll is just on the Nose )
It's raining right now , just checked the weather forecast .... A weeks worth of rain apparently !
 
Ok .......
The factory edge was to put it very kindly - Rubbish !
It had a roll , a full length roll ..
SO the edge was not flat or straight .. It actually rolled changing the angle as it went ! ( See Video )
I re profiled on the guided knife sharpener ( 1 hour @ 120 grit ) and then cleaned up the edge with 320 grit ( That coarse grit edge I was after )
Now there were some remnants of the 120 grit , as I took the 120 all the way to Bur City ! ( Bur both ways ) ..
So the 120 did get to the very edge and there was still some 120 left after the 320 work out .
Failure ? If you want to call it that was around 500 slices .. That's only a 350 slice increase ..
And I called it COS :
A) I was freezing my Bee Hive off
C) Those niggly 120 grit parts of the blade got worse and caught the paper . ( Coarse Grit Life )

Seriously , gone from a 150 roller to 500 slices ( Full Scandi ) .. And what happens when those 120 grit teeth are worn away by the 320 grit or replaced by 320 grit ?
Will it go even further ? It seems I can stop hating on the Garberg .. ( No I still purchased a rubbish knife with a factory rubbish edge - That's not going to change )
Hmmmm , so a fully re profiled edge & coarse grit sharpened . Coarse grit edges kind of look McNasty , but certainly seem to perform .
I have re sharpened the Garberg 320 and put it away .. Time for another disappointing knife to wear a coarse edge .

 
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Review - Mtech MT-20-70 Stainless Steel

Time to test another knife ! A) Factory edge was fabulously FUBAR .. B) 1st edge was a guided edge and was done to 20 degrees . This edge rolled at 100 slices . C) 2nd edge was ground , then guided at 22 degrees . This edge rolled at 150 slices D) 3rd edge was guided at 22 degrees , I put too...
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Mtech 20-70 Budget Bushcraft Knife ...
I say budget , cos the performance was bellow average ( 100 / 150 range )
This knife was given a fresh 60grit grind some months ago for a re test .
But all that bad weather .. But hey , now were doing coarse grit sharpening ( testing ) , and this knife has been dying to be re tested .
So I will put the 60 grit edge to the rope and then re sharpen the knife 240/240 and see what happens .
Might be interesting ?
 

60 Grit grind / wet stone grinder ..
I was a little more aggressive this time around ( removed more material ) ANd the result was a 250 slice roll ( Jam roll ? )
AN increase from a previous best of a 150 Roll

Now for coarse grit testing , I put down a 240/240 grit edge ( 240 both sides ) .. This resulted in a 350 slice Roll ..
Yes the knife is still a roller , but we have pushed the roll out to 350 slices rather than 100 or 150 .
A very disappointing knife is now a decent knife all thanks to the coarse grit edge .
And it still strops back strong .. On pure leather , so there is that as well I guess .
 

Review - Mora Pro C VS Pro S

Yes , that's right ! Another head to head edge retention test , Stainless VS Carbon . This time it's Mora . The Pro C VS the Pro S . If you look at the prices and you live in Australia , those prices are rather good for the Pro C & Pro S . I don't normally mention Retailers , but SSA seems to...
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Mora Pro C & Pro S
Both knives got the guided knife sharpener 320 grit treatment ..
It's jaw dropping how poor the factory edges were .. Really showed up on the guided knife sharpener ..

Pro series Mora's put to the rope next ( when ever the rain lets up ) .
 
As Gomer used to say - Surprise / Surprise / Surprise !
Moraknive Pro S


320 grit edge done on the guided knife sharpener hits 500 slices without a fail .
Yeah sorry , I'm sniffling ( runny nose ) and I was cold .. ( Too old for that sort of S )
I prefer to be a little more comfortable than freezing my BeeHive !
Butt & what a huge butt at that ! We have gone from a previous best of 200 slices ( polished edge ) to some 500+ slices with a 320 grit Diamond edge .
That's 150% Extra ... & then some ! ( Cos it did not fail )
Yes the edge was deteriorating , but still slicing ..
And the strop back was crazy good .. Less than a minute on pure leather to restore the edge !
Well , I'm learning something ..............

 
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Razor Blades Stalker ..
240 grit edge ..
Previously this was a 90/120 slice knife ..
Oh dear ! I was disappointed !

What about now ?
It's still a little thick behind the edge me thinks and maybe the bevel should be tightened .. ( Slice better )
Anyways , a 350 slice fail with excellent strop back .


I think I will call it there for 240 grit .. It's doing the job = Lifting a knives Game !
Coarse grit sharpening works .. There has been no Fail as yet ( loss of performance )
How ever , with really soft steel , the diamond did not beat out my 60 grit grind . ( Wet stone grinder ) Didn't lose / but no gain either !
But those Mora's really took to the 320 grit .. Did they ever ! ( Scandi )
So I may have to dedicate some rope to Scandi testing .
 
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