Making a knife hair popping sharpe?

[Zammo]

I'm the first to admit that I have been pretty useless at sharpening knives. But recently I seem to have got the knack of it and have managed to sharpen up my extremely blunt bushy, SAK and Frosts Mora so they all cut through paper with ease. I even managed to shorten my SAK, so it was less than 3" and added a new bevel to the tip of it.

My technique for sharpening is to use a knife sharpener block thing I purchased from lidl. I run the blade across each side of it (there are 4 different grades on it) 40 times on each blade side. The first 20 I focus on the base to middle of the knife and the second 20 on the point of the knife. Then once this is complete I give the knife a strop, again 40 times on each side focusing first on the base/ middle and then the tip of the blade. But however much I do this the knife never seems to be hair popping sharp am I doing something wrong?


Heres a few pictures of my knife sharpener if people are unsure what it is:

 

[g4ghb]

can you reduce the size of the pic a but mate - we can't read the whole post!

 

[g4ghb]

oops - too slow - you're already on the ball!

 

[jungle_re]

leather strop full of autosol and strop it till it shines like a mirror

 

[gregorach]

Yeah, stropping is the secret.

 

[Nagual]

I have a similar set of sharpening doodaas - not in a block but separate from a local iron monger. Took me a while to get the knack of it, at first I thought it was the cheap stones, as they only cost about a fiver or something. If I remember rightly I spent several hours messing about. I think I started to do the counting thing 300 swipes per side on the rough then 500 on the medium them many many many on the smooth. I got to the smooth bit and stopped counting after a few hundred passes I changed to doing one for one alternate passes. No idea how long I spent on that but eventually it did cut hair on my arms. Having said that, once that sharp it doesn't stay that sharp for long unless all you are doing is cutting arm hair I guess.

The only thing I see you doing different is doing different parts of the knife at different times. I wouldn't do this as you may end up with slightly different bevels. Try just sliding the bevel along as you draw the knife down so you cover the entire length of the blade in one pass. Other than that, sorry I have no idea, I'm far from being an expert on these things.


Nag.

 

[Barn Owl]

Are you stropping correctly?

Lifting the blade maybe causing the edge to turn over.

Do it on a level surface following the bevel angles as when sharpening.

 

[bushtuckerman]

whih of these should be used to strop a sharpened knife?:

http://www.thepolishingshop.co.uk/acatalog/Polishing_Compounds_800gm_Large_Bar.html

 

[stanley lake]

I have a similar set of sharpening doodaas - not in a block but separate from a local iron monger. Took me a while to get the knack of it, at first I thought it was the cheap stones, as they only cost about a fiver or something. If I remember rightly I spent several hours messing about. I think I started to do the counting thing 300 swipes per side on the rough then 500 on the medium them many many many on the smooth. I got to the smooth bit and stopped counting after a few hundred passes I changed to doing one for one alternate passes. No idea how long I spent on that but eventually it did cut hair on my arms. Having said that, once that sharp it doesn't stay that sharp for long unless all you are doing is cutting arm hair I guess.

The only thing I see you doing different is doing different parts of the knife at different times. I wouldn't do this as you may end up with slightly different bevels. Try just sliding the bevel along as you draw the knife down so you cover the entire length of the blade in one pass. Other than that, sorry I have no idea, I'm far from being an expert on these things.


Nag.

mite be you need a better blade mate

 

[FGYT]

if thats the same sharpener i have ( got mine from B&Q)

the finest grade is 600 which is still fairly course so the stropping wont work very well

To be honest i dont use the courser grades 200, 300 , 400 on my knives i wouldnt have much blade left i use it mostly for reforming old damaged blades etc or my big old splitting axe

ahve a look at he £5 sharpening kit posted in the stickys

ATB

Duncan

 

[Nagual]

mite be you need a better blade mate

Well perhaps.. Although to be fair, it was and still is my first bush knife, having never used a sharpening stone either it took a while to get the technique right. Oh it and it's a Mora..


Nag.

 

[alpha_centaur]

You should be able to get it really sharp then.

I sharpen mine on a DC4 (I think) stone, on the ceramic side, and then strop it and it ends up realy sharp. In fact its the only knife I have so far manage to get that sharp.

 

[Zammo]

if thats the same sharpener i have ( got mine from B&Q)

the finest grade is 600 which is still fairly course so the stropping wont work very well

To be honest i dont use the courser grades 200, 300 , 400 on my knives i wouldnt have much blade left i use it mostly for reforming old damaged blades etc or my big old splitting axe

ahve a look at he £5 sharpening kit posted in the stickys

ATB

Duncan

I only really use the two lighter grades on my knives now (400 & 600). The only time I used the rougher ones was when I shortened my SAK. I'll give that sticky a look though, cheers.

You should be able to get it really sharp then.

I sharpen mine on a DC4 (I think) stone, on the ceramic side, and then strop it and it ends up realy sharp. In fact its the only knife I have so far manage to get that sharp.

I have a DC4 aswell, but I stopped using it in favour of the sharpner block above. I'll give it a go now though, see if it makes any difference.

Lastly Barn Owl & Nagual I don't think i'm doing my stropping wrong, but if anyone has a link to a guide so I can make sure that'd be appreciated.

 

[Zammo]

Just tried it with the DC4.

Again the knife didn't cut any hair so I tried running the blade the other way down my arm and it cut the hair as well as removing a dead skin!

I'm not sure if using the DC4 made the difference or if all along it was sharp enough but I wasn't running the blade the right way.

But anyhow thanks for everyones tips.

:You_Rock_

 

[Ratbag]

if thats the same sharpener i have ( got mine from B&Q)

the finest grade is 600 which is still fairly course so the stropping wont work very well

<snip>ATB

Duncan

I agree - I think your edge is still too rough on a micro level to get really sharp. Look at it using a hand lens and you'll probably see the problem.

You can remedy this by using the diamond (rougher) side of the DC4 to grind out the micro scratches, then polish on the ceramic side and finish on a loaded strop.

At that stage you could also try putting a micro secondary bevel on the stropped blade using the ceramic side of your DC4. That'll help it stay sharp for longer, although it might be marginally less good at woodcarving.

HTH

Rat

 

[robin wood]

I think there are two things that could have made the difference. I agree with other folk that your diamond sharpeners are very coarse and the DC4 will be much finer grit, the diamond should still give an edge but it would be a very sawtooth edge and quite likely with a big burr.

The DC4 will be a good step down to a finer grit removing the big grooves cut by the diamond.

The other thing that may have happened is you may simply have just got to the stage where you have removed the secondary bevel which the Mora comes with from the factory. see this thread.

http://www.bushcraftuk.com/forum/showthread.php?t=29512

If you take a knife like a mora which has a secondary bevel and lie the primary bevel on a stone and start removing metal then for quite some time all you are doing is grinding the primary bevel and you are simply not touching the edge at all. If you do this you can go down the grits and polish the primary bevel as much as you like but the edge is actualy exactly the same metal as you started with. It is important then with your coarsest stone/abrasive to make sure you have reached the edge. You can check this either by putting marker pen on and seeing that it is removed right to the edge and/or by checking that you have created a burr all the way along. No burr with a coarse stone means you have not touched the edge. Then and only then go down through your grits anto the DC4 and finally strop.

Personally I sharpen a mora with a secondary, it is what they were designed to have and it takes less than 2 minutes from very damaged knife to "scary sharp" because you are removing very little metal only at the edge.