Sharpening: A serrated knife?

[pe2dave]

A good quality bread knife. Quite severe serrations.
Been excellent on new bread until recently.

any suggestions on sharpening please? Currently tried (too small) diamond coated file... partially successful.

 

[Rorschach]

Diamond files are usually too coarse. A purpose made diamond hone works very well but slip stones or even wet/dry paper glues to a dowel work well. Do each serration first and then remove the burr lightly on the flat side, job done.

I recently sharpened up a very nice victorinox carving knife this way and now it is absolutely razor sharp, really great knife. Serrated knives are highly underrated and usually looed down on by knife snobs.

 

[Tris]

Depends on the blade type but if possible sharpen on the flat side only if that makes sense. If it is scalloped both sides a knife steel will do the job if it isn't badly blunted. Failing that a round hone/ stone of suitable diameter and go one space at a time. There are bound to be other ways but that's how I've done them in the past.

 

[Phil Pascoe]

I've sharpened ...... just wiped over ........ the flat side with a diamond so many times the serrations disappear. It becomes a ham knife, just as sharp.

 

[Rorschach]

Depends on the blade type but if possible sharpen on the flat side only if that makes sense.

A couple of my knives can be sharpened like that but in general I have found this technique doesn't work that well for various reasons.

 

[pe2dave]

Serrations one side only. I'll try fine emery (wet) on a dowel.. Thsnks.

 

[Argus]

If the serrations are on one side only, the the blade is 'handed' - i.e. serrations on the right with the left hand side flat means that it will favour a right-handed person, giving a vertical slice cut used in a right hand. It will deflect to the side if it's used in the left hand........ in the same way as a side-axe. A knife with those features reversed will favour a left-hander.

This means that sharpening is quite straightforward if you have the basic kit.

You need a slip stone or curved diamond file with a suitable grit size that has a curve able to fit inside and traverse each serration - or do the same with a piece of emery on a stick. It's important the it will fit inside and stroke the entire serration - it won't work if the size and width is bigger than the serration - it will just sharpen up the corners and leave the middle bit blunt.

Swipe each serration equally, in turn with a downward rotating motion so that you raise a slight 'hair' on the flat side and finish off with a flattening of the back on a flat stone and a piece of leather to remove the fine wires.

Good luck......

 

[pe2dave]

@Argus - 'fit inside the serration' I think this is fairly key.
Quite surprised at the 'handedness' of knives, though from your desc, mine is 'right handed'.
IMHO you're being a bit simplistic re requiring a good fit? A smaller needle file yes, does 'half' the single serration, but (as with a saw)
move on and come back doing the other half, though yes, a good fit would make this easier!

 

[D_W]

buffer either with a hard buff or a felt wheel and reasonably strong compound.

Eventually, you will round over the serrations, but you could reinstate them if you really felt like it with a diamond burr (it's not necessary).

Be careful if you use my hard buff trick - they will be far sharper than you're expecting, and since the serrations make the angle introduced to your testing or feeling fingers different, you can accidentally cut yourself just seeing if they're sharp.

The virtue of this is they'll be sharper than you've ever seen, and it'll take a minute or two (if you're using a felt wheel with a heavy hand, make sure you don't overheat them).

 

[Argus]

@pe2dave

I'm not sure about the shape of your serrations. I'm assuming that they are curved. Mine are about 4 to 5 mm across and the inner section is curved.

Therefore I have a set of curved, pointed diamond needle files, with a radius narrower than the serration that I use to take a descending, rotating sweep across the serration - not too complicated. It's a bread knife and I do that maybe once or twice a year.

A knife edge that has one flat face will concentrate the forces on the opposite side.... hence Side Axes are sharpened flat on one side with the bevel taken to a very fine edge on the other and is capable of taking very fine shavings. A right-hand Side Axe is impossible to use as intended, for fine shaping and removing shavings, when it's held in the left hand...... and vice versa a left-hand Axe.

If you are right handed and your knife is also right handed - (with the left side being dead flat), try it out. Take a thin slice of something in your right hand, then do the same thing in your left and see the difference. You should have a parallel slice with the first and it will veer off to the left in the second.

 

[pe2dave]

Your explanation is quite logical @Argus but .... I wonder how many people realise they are 'handed'!
I honestly don't think I could cut a slice of (new) bread left handed (I know I can't saw left handed!).
Bread < 12hrs fresh is a b to slice finely though, hence the need for a good (sharp) carving knife.

 

[Jacob]

I know enthusiastic sharpeners see this as a challenge and want to make it as difficult as possible but the whole point of serrated knives is that they are really easy to sharpen:
Just two or three swipes with a steel, every now and then.
I first discovered this about 60 years ago when my mother was complaining about bluntness and having to buy a new knife.
I've been doing it ever since. Current knife is serrated Sabatier about 20 years old, will see me out.

 

[pe2dave]

Disagree @Jacob? My (oval) steel is a lousy fit to the serrations ;-)

 

[Jacob]

Disagree @Jacob? My (oval) steel is a lousy fit to the serrations ;-)

You ignore the serrations and just steel it as for a normal knife. Down one side, down the other, 2 or 3 times, about as simple as you can get, about 5 seconds work.

 

[Argus]

@@pe2dave
Not many people realise the subtle geometry of a blade that has a single dominant bevel. It's a bit like using a chisel upside down; it will cut, after a fashion, but.......

I had this scenario in the kitchen dept of a very well known up-market department store some while back, you know the one.... it has 'partners' instead of employees.

I asked for a serrated bread knife similar to the one in a huge display behind the counter and the operative couldn't understand why I rejected the one I was presented with because it was left-handed..... she thought that I was being, how may I put it?.... 'Awkward'

Anyway, Good luck with the sharpening. This topic is now degenerating into one of those interminable 'sharpening' fandangos....... I'll leave it there and enjoy the rest from a safe distance.

.

 

[D_W]

I know enthusiastic sharpeners see this as a challenge and want to make it as difficult as possible but the whole point of serrated knives is that they are really easy to sharpen:
Just two or three swipes with a steel, every now and then.
I first discovered this about 60 years ago when my mother was complaining about bluntness and having to buy a new knife.
I've been doing it ever since. Current knife is serrated Sabatier about 20 years old, will see me out.

or, you could do something like use the buffer or deburring wheel and have a knife that's truly sharp instead of sort of.

I stopped using serrated knives a while ago (but daughter and spouse still use one, so I have to sharpen it from time to time).

Bake a lot of bread, too - a japanese chef's knife (or any chef's knife, but a thinner bevel is better) that's really sharp will cut fresh bread (still hot isn't a problem) without issue and do a neater job.

 

[Jacob]

@@pe2dave
Not many people realise the subtle geometry of a blade that has a single dominant bevel. It's a bit like using a chisel upside down; it will cut, after a fashion, but.......

I had this scenario in the kitchen dept of a very well known up-market department store some while back, you know the one.... it has 'partners' instead of employees.

I asked for a serrated bread knife similar to the one in a huge display behind the counter and the operative couldn't understand why I rejected the one I was presented with because it was left-handed..... she thought that I was being, how may I put it?.... 'Awkward'

Anyway, Good luck with the sharpening. This topic is now degenerating into one of those interminable 'sharpening' fandangos....... I'll leave it there and enjoy the rest from a safe distance.

.

They aren't "handed" and they aren't subtle.

 

[pe2dave]

Do you really want to stand out as Mr Awkward @Jacob?
My second poster 'blocked' here.

 

[Rorschach]

Most serrated knives I have come across are right handed which is annoying as a leftie. I only have one left handed serrated knife but it's quite thick in the blade I don't really care for it much.

The tendency to slide off to one side is an issue with certain food stuffs but if you know it's going to happen you can account for it in your cut and do a reasonable job. This is only food after all, a wonky slice of cheese isn't going to kill you.

Oh and also it depends on the blade too. The victorinox I mentioned is right handed, but because of the shape of the blade it still cuts very nicely for a leftie.

 

[Jacob]

Most serrated knives I have come across are right handed which is annoying as a leftie. I only have one left handed serrated knife but it's quite thick in the blade I don't really care for it much.

The tendency to slide off to one side is an issue with certain food stuffs but if you know it's going to happen you can account for it in your cut and do a reasonable job. This is only food after all, a wonky slice of cheese isn't going to kill you.

Oh and also it depends on the blade too. The victorinox I mentioned is right handed, but because of the shape of the blade it still cuts very nicely for a leftie.

Whichever hand you use you have to resist the tendency of a one sided bevel to twist. If you just do it by eye it works fine and becomes normal.
PS just had a quick google - it's a major topic with knife enthusiasts! I might have known!