Getting rid of a second bevel

[superc0ntra]

You need an old fashioned grindstone with lots of water

 

[MartiniDave]

"an old fashioned grindstone with lots of water "

I'd love to stumble across one of those for sale cheap!

 

[mrcharly]

This is what I have:

https://www.machinemart.co.uk/shop/product/details/cbg8w-whetstone-grinder

I didn't pay that much for it!

 

[cave_dweller]

I don't know about the Companion, but I believe a lot of Moras are supposed to have a micro-bevel, and aren't 'zero scandi' at all when they leave the factory. There was a good post over on BB about it. That doesn't mean your knives are as they should be of course (who knows what's been done to them!). However it might mean that you don't need to go right back to a 'real' scandi to get them cutting properly. Maybe a micro bevel is the easiest way forward?

Here's the post: http://www.britishblades.com/forums/showthread.php?54593-is-your-MORA-too-sharp

And a picture from it:

 

[Harvestman]

Does the company pay you? If so that's not an economical use of your time at all - for £90 you'd get 30 new knives
http://www.building-supplies-online...bqVJqlDo63tkYA3TnRzc1Fh5J9zhSR1ej0aAjgo8P8HAQ

they'd probably even claim the vat back.

I'm just going to add here that these are damn good knives, especially at that price, and mine has become my go-to knife under most circumstances. I know very little about sharpening except that I am bad at it.

 

[cave_dweller]

I'm just going to add here that these are damn good knives, especially at that price, and mine has become my go-to knife under most circumstances. I know very little about sharpening except that I am bad at it.

Agreed. They are excellent.

To the OP: Bear in mind if you consider these, they aren't 'properly' scandi ground. Mine has a tiny, but visible, micro-bevel

 

[demographic]

I don't know about the Companion, but I believe a lot of Moras are supposed to have a micro-bevel, and aren't 'zero scandi' at all when they leave the factory. There was a good post over on BB about it. That doesn't mean your knives are as they should be of course (who knows what's been done to them!). However it might mean that you don't need to go right back to a 'real' scandi to get them cutting properly. Maybe a micro bevel is the easiest way forward?

Here's the post: http://www.britishblades.com/forums/showthread.php?54593-is-your-MORA-too-sharp
And a picture from it:

Looks like I'm agreeing with Robin on that one then. Thats my definition of a secondary bevel.
I sold Robin a big wet electric grinding wheel a few years ago, I wonder how he got on with it.

 

[Tommyd345]

To try and answer everyone at once and give an update,
The centre wants a zero grind (no second bevel (is that the right term?)) so that it can be sharpened easier, by just rolling it up onto the bevel to sharpen on our stones. Today I went to the shop and brought a 300 grit diamond sharpener, it's far more coarse than our Japanese wet stone, and it makes things go a tad quicker I'm still struggling to get a good edge but I think it's just because there's microscopic areas still with the second bevel on (as mentioned below)
I also tried the brick idea but It didn't seem to be doing anything but scratch the knife and mark it red, so I gave up on that one!
With a belt sander do I need to get some sort of abrasive paste or just a really coarse paper?

 

[janso]

I think you can get ceramic belts for sanders which are better at re grinding a blade bevel? The tool shop that Ben Orford uses stocks them - Axminster tools?


Sent from my hidey hole using Tapatalk... sssh!

 

[OldJimbo]

With a belt sander do I need to get some sort of abrasive paste or just a really coarse paper?

A regular woodworking belt will do fine for a start. It's really tough to figure what's going on without a lens, but it's very important to get one knife fixed just to see if the temper has been removed.

I don't know about the Companion, but I believe a lot of Moras are supposed to have a micro-bevel, and aren't 'zero scandi' at all when they leave the factory.

Certainly a microbevel is new, but I'm betting that it's put on either for cheap sharpness or to cover up some issue with automated grinding and polishing. The real issue is that the large cutting bevels aren't flat but slightly concave, and as you flat grind them, the edge flakes off being uneven. It's only when you have a consistent and strong wire edge that things are in shape. We've put lots of different edges on Moras even making the whole blade full convex, or putting on V bevels, but getting everything uniform first has always been worth the effort.

I've always been amazed by the people who have trouble with Moras - because while I put effort into a knife before using it, I then don't have any of the edge problems - and I choose to use acute edges. A microbevel stuck onto a knife where you can see that the primary cutting bevels have issues is clearly not for long term use, but it'll lead to more undeserved criticism of Moras as people try to sharpen using that microbevel as a guide.

 

[petrochemicals]

If your worried about the temper you could have a quick read of this;

http://www.abrasiveengineering.com/therm.htm

 

[Tommyd345]

So as another update, I have managed to get an edge on the majority of the knives. They are by no means fixed, there is still a visible second (sloppy) bevel but somehow they all have an edge that is sharp enough for feather stick-ing However I am confused, I unfortunately couldnt get access to a belt sander or any equipment, just myself, a whetstone and some iron maiden. So just using the whetstone, how come there is a sharp edge when the second bevel is still visible? I was careful to make every stroke the right angle to the original bevel, I even used a highlighter on the blade at times, just to make sure! hmmmmm

 

[Robson Valley]

Maybe this experience might have some bearing.
I bought a nice blade recently. Fully expecting to revise the bevel to 12 degrees for wood carving, like all my other knives.
Could not get there. Carving tests in wood were hopeless.

10X magnifier and I see a wee little blunt bevel on the BACK SIDE of the dang blade as well.
I have a round, 2-grit, Carborundum brand axe stone.
5 minutes or less and I jointed/squared off the entire edge to just beyond where the dumb back bevel had been.
OK, begin again. 30 minutes and I now have the carving sharp edge that I expected in the first place.

Jointing the edge is fast. Rough revision of the bevel you want is fast. Some finesse in refinement and you're there.

 

[OldJimbo]

how come there is a sharp edge when the second bevel is still visible?

I think that what you've accomplished is to remove the worst parts of the top shoulder of the secondary bevels and so allowed the allowed sharp edge to cut properly. The problem is how to sharpen that edge when it gets blunt. Unless the person who put the secondary bevels on was good, I'm also betting that you have sharpened parts of the edge.

When you cut feather sticks with the grain of the wood, the wood rides up the steep secondary bevels to their shoulder, but then it is your primary bevels which open the cut and pry apart the grain with the edge not even touching anything. So smoothing the top shoulders of bevels has an amazing effect in cutting ability - which here is more of a splitting ability. Unfortunately when used for other cutting tasks, the edge is likely to blunten fast.

It all sounds hugely unlikely, but I am a confirmed believer that I can take a properly finished Mora (bevels) and make it work better by honing the "flat" sides. Essentially I am simply evening out the top shoulders of the huge Scandi bevels, just as you are doing with the top shoulders of the secondary bevels.

Unfortunately, being able to shave feather sticks still won't show if temper has been lost. It's really important to get one knife fixed, and then do some cross grain cutting and scraping. Fixed can mean either going the full route with the original Scandi or putting on a decent secondary bevel with large abrasive surfaces. When the secondary bevels were put on, the edge was probably made irregular - not straight. So a halfway job will only really sharpen the high spots of that edge, and then you might think fast bluntening was due to loss of temper, when it's really due to a poor edge. So you have to get a good edge before making a decision about the shape of the blades.