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Greg S
14-11-2004, 12:38 PM
Sorry to burden PF1'ers with this, but I can't find an NZ specific hardware forum to go to for help...

I've tried to find a decent sharpening stone to sharpen my kitchen knives, and although I've bought three in the last year, none of them does the job properly. They're only of use for sharpening crude tools like axes and hatchets.

The ones I've bought ranged in price from about $3 to $25, they're all aluminium oxide, and they all soak up the oil like a sponge. This is the problem! The one I had overseas used to hold the oil in a nice film on the surface of the stone, allowing me to achieve a level of sharpness for my chisels that I could cleanly shave the hair from my arm!

But the damn local ones I've tried just soak up the oil, which means my delicate knives get virtually rasped, and wears them down excessively.

Of course I've tried a range of oils, form typical 3-in-one to high viscosity engine oils. Even cooking oil! GRR

Any recommendation/advice on a brand and where to purchase will be appreciated!

Thx.

somebody
14-11-2004, 12:43 PM
Apparently the "diamond" type ones are quite good. I had a friend who would swear by his, and said that he could sharpen any knife with it, no matter how blunt it was.

Graham L
14-11-2004, 12:44 PM
You want the best? Have a look at an engineers suppliers for a diamond sharpener. Looks like a bit of steel with perforations. (like a colander, but flat). George Henry's in Christchurch have a couple on the counter for people to try out. ;-)

TonyF
14-11-2004, 12:49 PM
Go to House of Knives in Mt Eden Road. They stock everything. There are also a couple of websites with pages of stuff on How to Sharpen.

Cheers Tony

Greg S
14-11-2004, 12:53 PM
Thanks all - yeah I suppose I better go to a kitchen supplier specialist. (I see $'s going out the window) :(

Somebody - as for the Diamond brand - that was the cheapest one I got, and it's lousy. Sure... it DOES sharpen my knives, as they all do, but not to the fine razor-blade extent I want, and they all damage the edges

Murray P
14-11-2004, 12:54 PM
I use an old carpenters oil stone, probably cost $20- 2o years ago, good stones cost real money. I alternate between fine machine oil or CRC type and turps or kero for sharpening anything with a stone. Wouldn't let a knife or garden implement anywhere near my good, un-worn un-chipped, stone.

How course are these stones? For finishing, most sharpening for that matter your tools should not get that bad that you need to use the course side, use the fine face which will provide little resistance on a finger run across it. Test by how efficiently it shaves, if it leaves some hair, crops them too high or takes some skin, it's blunt.

Look for the Bear logo, other than that I can't remember a brand or the material other than some stones have the brown abrasive on the fine side (current good stone), some a darker grey on the fine side (current knife stone).

Murray P

TonyF
14-11-2004, 12:59 PM
> Thanks all - yeah I suppose I better go to a kitchen
> supplier specialist. who may well sell you something, but the Mt Eden Rd folk will talk all about sharpening.

Anyway, see http://www.worldknives.com/sharpening2.asp
Cheers
T

Graham L
14-11-2004, 01:01 PM
We weren't referring to a "Diamond" brand (sounds like pasta ;-)) ... but to a diamond sharpener. The girl's best friend type.

Greg S
14-11-2004, 01:02 PM
> I use an old carpenters oil stone, probably cost $20-
> 2o years ago, good stones cost real money.

That sounds exactly the kinda thing I'm after - but the point is, the stone needs to hold the oil and not absorb it.

Greg S
14-11-2004, 01:04 PM
> We weren't referring to a "Diamond" brand (sounds
> like pasta ;-)) ... but to a diamond
> sharpener. The girl's best friend type.


Oops! :8}

Yeah my Diamond is a brand... el-cheapo from Taiwan or somewhere! LOL

Greg S
14-11-2004, 01:10 PM
> see
> http://www.worldknives.com/sharpening2.asp

That's a fair run-down on sharpening, but I disagree with some of it. They reckon that no lubricant is required, whereas my experience says a lubricant (oil) is needed because it has a less harsh effect on what can be a relatively brittle edge.

Anyway, I know how to make a good edge - I just need a damn medium to create it from.

Thanks for the link though - I'll read it again

Graham L
14-11-2004, 01:10 PM
Norton are well regarded for "stone" stones. They probably have them made in China now, but I'm sure they would still be better than the ones you find at Mitre 10, or the Warehouse.

Again, have a look at an engineers suppliers. Their prices are probably more realistic than those of a fashionable kitchen shop.

Murray P
14-11-2004, 01:14 PM
> > I use an old carpenters oil stone, probably cost
> $20-
> > 2o years ago, good stones cost real money.
>
> That sounds exactly the kinda thing I'm after - but
> the point is, the stone needs to hold the oil and not
> absorb it.


The course side (or stone) will absorb more oil than the fine side. The stone will initially take up oil until it can absorb no more, in fact the surface can get clogged with oil and metal, especially if it is porous, heavy oil is used and the metal is soft. Every now and again I alternate oil with turps or kero (somewhat oily anyway) to keep the stone clean. If you exclusively use turps or kero the stone wears more quickly and will get out of true.

I'm intrigued by the diamond ones GL has mentioned though. Using oil stones on kitchen tools is a bit messy and not a quick touch up type of operation.

Murray P

Murray P
14-11-2004, 01:17 PM
> Norton

That's it Graham.

Murray P

mikebartnz
14-11-2004, 01:21 PM
>the stone needs to hold the oil and not absorb it.
Until the stone has absorbed enough oil you will not get a film. A new stone can take quite a bit and then I just use some good old spit.

Greg S
14-11-2004, 01:27 PM
> >the stone needs to hold the oil and not absorb it.
> Until the stone has absorbed enough oil you will not
> get a film. A new stone can take quite a bit and
> then I just use some good old spit.


Sounds reasonable enough, but what if I used half a cup of oil and it still didn't film on the surface!

I'm suspecting that the stone I used in UK was a completely different material.

Anyway, I think I'll just drown one of the suckers in a bucket of cheap motor oil and try again.

And ps... my middle priced stone is a Norton - cost about thirteen bucks from Bunnings

somebody
14-11-2004, 01:44 PM
Sorry... not Diamond brand, I meant the diamond type - the stones with industrial diamond implanted in the surface.

somebody
14-11-2004, 01:46 PM
Some stores have professional knife-sharpening services. It might be worth giving one of those places have a try (I know some Mitre 10 stores do it, and many knife specialists also do it).

jeep
14-11-2004, 01:59 PM
A couple of points here..firstly try kerosene instead of oil. and secondly, if you have any half decent knives in the kitchen, then think very seriously about NOT using a stone on it. The good quality german steel knives usually hold their edge pretty well and all that is needed is a couple of swipe along a SHARPENING STEEL which will bring the edge back in order pretty quickly. You would normally only use a stone on these knives if there has been some damage to the edge eg chopping bones.
Of course, if they are just common muck metal knives, then good luck to you!

Terry Porritt
14-11-2004, 02:13 PM
Oil stones need to be soaked in oil overnight or longer.
In the "olden days", heated tallow was used to soak into the stone.

The Norton Bear Brand stones used to come in 3 types, the Silicon Carbide Crystolon, The brown India stone, and the ultra fine white coloured Arkansas stone for that last super razor finish.

I will read what it says on my Arkansas box.. "Bear Brand ARKANSAS is an ultra fine grit stone made of natural novaculite rock". It also says that Bear brand sones are oil filled at the factory.

I usually use kerosene to loosen up the surface and float the muck out. Then re-oil with engine oil every so often

When you buy a stone, take a straight edge with you to check for flatness. The cheapo Chinese made ones at your hardware shop are often warped and not good for chisel or plane blade sharpening.

For my sins as an apprentice I spent 6 months tool and cutter grinding :)

El cheapo knives made of "stainless steel" wont take an edge anyway.

You need a hardened steel. The knife I carry tramping is made from hardened 440C stainless, 60 Rockwell C, and goes under the name Hi-Cut, made in Japan.

It will take a razor edge finish and slice through supple jack in one go.

Terry Porritt
14-11-2004, 02:21 PM
Hmm, checking in the garage, I see I have a New Zealand Norton Aluminium Oxide combination stone, a Carborundum brand Silicon Carbide one with no country of origin, and a Norton India combination stone made in Brazil!

exLL
14-11-2004, 03:12 PM
The following are comments only, not recommendations.

The instructions that came with my sharpening stones says: To prevent glazing and ensure a fast, clean cutting action, the use of a thin clear oil is recommended. (D.F. Neatsfoot Oil is ideal.) if the stone becomes clogged, wash with Kerosene.

My ancient tin of Davis Neatsfoot Oil states: For use as a softening and preserving agent for all classes of leather...it is an excellent lubricant for oilstones...guaranteed manufactured solely from animal tissues and free from mineral and vegetable adulterants... manufactured by Davis Gelatine (NZ) Ltd, Christchurch NZ. (That was way back in the 1960's by the way).

A couple of other thoughts:
My Dad used a leather strop to keep his razors sharp.

What about having a chat with a local butcher or other meatworker.

Cheers.

merlin-nz
14-11-2004, 04:06 PM
I cocur with Terry and exLL.
From my great grand daddy to me, trust in the advise given below by Terry ane exLL.

cheers merlin-nz ;-)



Oil stones need to be soaked in oil overnight or longer.
In the "olden days", heated tallow was used to soak into the stone.

The use of kerosene to loosen up the surface and float the muck out. Then re-oil with engine oil every so often

To prevent glazing and ensure a fast, clean cutting action, the use of a thin clear oil is recommended. (D.F. Neatsfoot Oil is ideal.) if the stone becomes clogged, wash with Kerosene.

My ancient tin of Davis Neatsfoot Oil states: For use as a softening and preserving agent for all classes of leather...it is an excellent lubricant for oilstones...guaranteed manufactured solely from animal tissues and free from mineral and vegetable adulterants... manufactured by Davis Gelatine (NZ) Ltd, Christchurch NZ. (That was way back in the 1960's by the way).

merlin-nz
14-11-2004, 04:08 PM
Bugger never Previewed sorry bout the speeling ;-) .
I think u can understand it.


cheers merlin-nz ;-)

mikebartnz
14-11-2004, 10:03 PM
As a prisoner of war (WWII) my father made a knife out of an old circular saw blade and it was an excellent knife and is still going although quite a bit smaller now though. They weren't allowed a point on them.

beama
14-11-2004, 11:09 PM
It does not need to be an oil stone and it does not become an oil stone until oil is applied to it.
In my previous profession (chef) we used water and dish washing liquid instead of oil and I've even seen attaway paste used as a lub' on a stone.
The secret to sharping knives is the angle (45 deg) and equal strokes on each side, clean and steel often (same angle) during the process and yes the true test of sharpe knife "can you shave with it" .
We used to use stones purchased from our local hardware store, you know the ones, duel surface, fine on one side course on the other

fairway
14-11-2004, 11:45 PM
OK..
how to sharpen a modern steel knife.
Edging tool... I.E a tool with either tungsten wheels or similar to give a new, even edge to the blade.
then a "steel" to take the burr off.
A "steel" can be of diamond compound, my preferance.
To use a stone of any compound would see you there for a month of sundays .. spitting tacks to boot.

Graham L
15-11-2004, 01:34 PM
An oil stone can be used without oil. Water is fine. But if oil is used, that stone must be used with oil ever after.

45 seems a bit savage to me. I use that on a cold chisel (uncluded angle 90 , but that's meant for splitting, driven by a hammer, not "cutting" with in a slicing action..