Stropping

[Wentworth]

There were some questions about stropping knives recently. I'm not an expert, but this technique works for me.

Burrs
After sharpening my knives on a stone, they are left with a "burr", which is a very thin, flexible piece of the edge. I try to minimise the size of the burr by going lighter and lighter with each stroke on the stones, but I still get them.

The problem I've had with burrs is that while the knife is shaving sharp, after a few minutes of use, the knife is dull. The burr tears off, leaving behind a dull edge.
I remove the burr by stropping the knife. You can also remove it by putting a micro bevel on, as mentioned here:
http://bushcraftoz.com/forums/showthread.php?5029-Putting-a-micro-bevel-on-a-scandi

I have tried leather loaded with two different stropping compounds from bark river, but I prefer using the rough side of my leather belt.

How many?
Ray Mears recommends stropping the blade 50 times. I used to do this and found that it did remove the burr and left a well finished edge.

I then experimented by stropping my knives 200 times (because 199 times is too few and 201 is getting obsessive). I found that this gave the edge the ability to "pop" hairs off my arm, rather than the normal "scrape/ shave" I was getting before. I'd guess the stropping gives the equivalent of a convexed micro bevel.



This drawing shows (from left to right)
1.)an edge with a burr
2.)an edge after the burr has ripped off through use
3.)a convexed micro bevel as a result of stropping

Technique
I have tried two techniques with stropping, one which I'll call a floating strop (because I don't know the correct terminology) and the other a supported strop.

The supported strop involves lying the leather down on a flat surface, with the rough side facing up.
I then lie the bevel of the knife down flush on the belt.
The next step is to tilt the blade slightly, creating a mm or so gap between the bevel and the leather.
I then drag the blade along the leather (edge trailing) with basically the weight of the blade.
Work both sides evenly.
I raise the angle slightly so as to create the convexed micro bevel as well as removing the burr.

You don't have to raise the angle to convex the edge, instead, leave the bevel flush and the edge will remain as a zero grind scandi.
The problem I have with this technique is that if I lose the angle, or apply slightly too much pressure, I can undo all my sharpening work and ruin the edge. But it obviously works for most people.

I prefer the floating strop technique. I pin the buckle of my belt under my right foot and hold the other end in my left hand, pulling the belt into a diagonal.

I then lie the bevel of the knife flush against the leather.

I don't bother raising the angle as with the previous method, because as I drag the edge along the belt, the very light pressure of the firmly held knife makes the belt dip slightly. You can see the angle in this photo

This "dip" or angle in the belt seems to do the same job convexing the the edge. It also seems to be a bit more forgiving than the other stropping technique as I've never ruined an edge this way.

I work both sides evenly.


I hope this is of use to some. If anyone can correct my terminology or theories, please let me know. Like I said, I'm not an expert by any means.

 

[AussiePreppers]

That was great. Thanks for posting.

 

[Arron The Archer]

good stuff wentworth well done..........may i add that if it's hasn't been already make this a STICKY!!!!!!!!!!!!!!!!!!! .



please :risatonaD:


then at least the same questions an threads don't keep popping up an it doesn't get lost

 

[Mountainwalker]

Thanks Wentworth, I have not seen that technique before. Looks easy, I will give it a go tomorrow.

Yes, agree with Arron, make that a sticky.

 

[Arron The Archer]

good part about using a belt is you can use nearly anything to attach it to like wrap the loop around a door nob, tree limb (as ray did in the video in "how sharp"), bull bar of a 4x4 etc
making it easy for bush use so there is no need to carry a dedicated strop (less stuff to carry)

 

[Thrud]

Cardboard works as a strop too.

 

[Toddy]

Neatly done Wentworth

The only problem with using a belt all the time is that you can end up with a really rounded edge since the belt flexes under the pressure of the blade. You need a heck of a pull on it to stop that happening.
That's why most folks who strop regularly have hard backed ones.
It's still (I think) the best method of keeping a blade trued up without constantly resorting to aggressive metal removal.

M

 

[silverback]

The strop I use for my leather tools is simply a block of pine say 200mm x50mm with a strip of leather glued on. This I give a dose of lanolin oil /machine oil or such and a dob of the red rouge for dremel tools. I rub it in all over and let it soak in. That's it. Current one is over a year old now and still works well and it gets a good workout as with leather tools you are stropping all the time. Just be sure to drag blade backwards and even amount of strokes each side. You could get anal and make one with green compound and one with white as well. They are different grit/grade. You can recharge these any time you feel it has stopped working,just a touch of oil and rouge and away you go again.

 

[Wentworth]

Hi Toddy, I can imagine if I went too long without using the stones, the "give" in the belt would make the convexed edge too obtuse. I use the stones once every month or two for the knives that get regular use, stropping or touching the edge up after every use.
Mountainwalker and Arron, I'll sticky this and the microbevel thread for now. We have a few knifemakers on the forums who could do a much more in depth tutorial I'm sure.

Is there any call for a tutorial on the use of stones, or is this too basic? Anyone here want to have a go, get some good angle shots and diagrams? I know there are some great photographers on board.

 

[Doc]

Thanks Wentworth. This is the method I use but I don't have the patience to do it 200 times!
Cheers
Doc

 

[Arron The Archer]

Hi Toddy, I can imagine if I went too long without using the stones, the "give" in the belt would make the convexed edge too obtuse. I use the stones once every month or two for the knives that get regular use, stropping or touching the edge up after every use.
Mountainwalker and Arron, I'll sticky this and the microbevel thread for now. We have a few knifemakers on the forums who could do a much more in depth tutorial I'm sure.

Is there any call for a tutorial on the use of stones, or is this too basic? Anyone here want to have a go, get some good angle shots and diagrams? I know there are some great photographers on board.

good point wentworth i was hoping you'd point that out it would take a lot of stropping to end up convexing the bevel a lot more than anyone would ever!! do while out bush
or a quick strop while carving on a day walk or even in the backyard an as you also point out it's always a good idea to true the edge/bevel with a good whetstone once a month or so
DEPENDING on how much you (meaning people) are using the knife..

thanks for making this a sticky mate it needed to be as it's very helpful an shouldn't be lost with every other thread......

i would do use with stones i've been using them for about 20+years but the video of ray mears using whetstones http://www.youtube.com/watch?v=Lm53mCOQTR8 is a lot better than i could do as all i have is a phone camera
an no idea how to do diagrams on computer (you've heard me say "bush stupid" before well i'm "computer stupid" getting on here an searching google for gear is as far as i can get lol)




Doc 200times was wentworths joke (as some people are seriously obsessed) you don't need to go that far...... all you need to do is strop enough times so you completely remove any burr an once you feel no burr a few extra times just to make sure it is completely gone an it all depends on the grit stones you've used the finer the stones (i go to 8000grit water or whetstone) the finer the burr an the easier it is to remove

 

[Toddy]

If you use your knife, and I do mean use, not just cut up dinner, then a quick swipe over the hone will not do. The basic number is 100; that's fifty back and forth. That's every time it is honed. A couple of swipes just polishes it.

Using a belt as the hone is known to cause rounding and uneven shaping. It's why old cutthroat razors had to be sent to be re-set. Razor strops were supposed to take off the burr, but too often men used the other side as a hone to sharpen and didn't keep the strop tight enough.

Using a hone to remove the burr from sharpening is one thing; using the hone to keep a knife sharp is another entirely.
Basically it negates the need to aggressively remove metal with stones or diamond files. It's trues up the edge and it keeps your knife lasting longer.
If you do it right.

 

[Wentworth]

Actually Arron I do strop 200 times :_s:

 

[AussiePreppers]

Toddy, what do you mean by honing? Fine stone? Fine sandpaper? Anything fine like ceramic rod, then strop it? Not quite following using the belt as a hone...

 

[Lepmeister]

I love a good strop. I have a piece of leather tied up at one end and i hold the other and pull tight. 50 times up and back ( so 50 per side) does a great job.

 

[Toddy]

Ah, sorry, I should have made myself clear.

Stropping keeps the knife sharp and burr free. It's a softly softly approach to it.
Honing on a strop can actually sharpen a knife from blunt. It just takes time and patience. Again, it's a softly, softly approach with minimal metal removal. It removes minor scratches and rough spots, but isn't ideal for dings out of the edge.

I think it was bringing up the razors that confused matters.

 

[Arron The Archer]

stropping like that is all well an good for expensive/custom knives like adventure sworn, ben orford or ray mears (waste of that kind of money not worth the wait IMO) etc because of what they cost you don't want to remove much metal at all but it's hardly worth the time on cheaper knives like mora, ENZO, HELLE, spyderco bushcraft UK (not that mine sees any use thanks to the G10) especially moras a 3000/8000 whetstone takes hardly anything anyway that's what they are designed for

sure stropping is a big help to an edge for carving work but there is no need to go over board unless it's an expensive/custom knife even then most people in australia would leave there expensive knife at home an take a mora or the likes anyway

 

[Toddy]

It's not a great effort Aaron, it's very simple. Takes a minute or two, let's you have a 'look' at the knife, make sure it's clean and dry and trued up before it's put away. It's a non aggressive sharpening that really works without fuss or bother. No need for stones

Toddy

 

[Arron The Archer]

all this is doing is going round an round i've said all i need to anymore can be taken up with me in pm an out of respect to Blake an the Mods i'll post no more on this topic


ps, my name is Arron it's scottish... Aaron is jewish

 

[Corin]

Ah, sorry, I should have made myself clear.

Stropping keeps the knife sharp and burr free. It's a softly softly approach to it.
Honing on a strop can actually sharpen a knife from blunt. It just takes time and patience. Again, it's a softly, softly approach with minimal metal removal. It removes minor scratches and rough spots, but isn't ideal for dings out of the edge.

I think it was bringing up the razors that confused matters.

I agree entirely.
Whilst it is some peoples choice to use stones, stropping certainly has a place and in fact is an excellent method of achieving a wonderfully sharp knife. This after all is a thread about stropping and not the use of stones.

Both techniques are legitimate and have their pros and cons, it comes down to the skill of the sharpener to determine which method is most appropriate for their knife, in the condition it is in.

Thanks for sharing your experience with stropping.