Honing oil? Oil stones.

[Billman]

BTW In the USA you can buy food grade mineral oil (a Texan chef told me about this stuff).

You can get it in the UK as well - somewhere I have a can of bacon slicer oil (my mum used to be head chef in a school kitchen)....

[SeanHellman]

To start with the original question, I now use mineral oil in the form of baby oil which I can get cheaper than any other oils used here. I want something on my skin that does no harm. My hands can suffer from dryness and soap to clean other oils of my hands will dry them out. I really do not want to wear gloves. Baby oil is harmless and can help keep my hands moist. Other oils and the thinners used are not something that I want on my skin.
With any oil stone you want the stone saturated with oil so that any more you put on will just float on the surface. This oil needs to be wiped or dabbed off at the end of the session. The oil is used, as has been said already, to float the metal particles away. Unless these particles are in suspension then they will probably clog the abrasive so it will no longer cut.

[bulldawg_65]

I know Christopher Schwartz uses standard olive oil. I do like Sean's idea of baby oil though. It is essentially mineral oil with fragrance added.

[Billman]

Olive oil, like most vegetable or natural oils such as linseed, rapeseed, will slowly oxidise and harden on contact with the air - that's the principle most oil based paints and varnishes use to harden (with added driers to hasten the process), so I would advise against use on a stone, unless you wash it in detergent after each use..

[ToneWood]

By the way, what is the difference between turps substitute and white spirit?? They both do the same job and look the same - but as some makers make and sell both, there is some subtle difference...

I looked this up on wiki once before: turps/turpentine is produced from wood while white spirit is a similar product typically derived from (crude) oil.

http://en.wikipedia.org/wiki/Turpentine

Turpentine (also called spirit of turpentine, oil of turpentine, and wood turpentine) is a fluid obtained by the distillation of resin obtained from live trees, mainly pines.

http://en.wikipedia.org/wiki/White_spirit

White spirit (UK)[note 1] or mineral spirits (US),[1][2][3] also known as mineral turpentine, turpentine substitute, petroleum spirits, solvent naphtha (petroleum) or Stoddard solvent,[4][5] is a petroleum-derived clear, transparent liquid which is a common organic solvent used in painting and decorating.

Note: the above pages include a Hazard/Toxicity section.

[ToneWood]

BTW I recently bought this combination waterstone from Amazon, it was cheap at the time:

I was curious to see how it would compare with the oil stones - & I thought it might be better to use water stones for kitchen knives.

It is still early days but I have several observations:

1. I much prefer using the oil stones - a little drop of oil is actually quicker, cleaner & smoother than all the water mess & drying up afterwards. Surprised.

2. This particular water- stone combination (400/1000) is quite coarse - too coarse for my kitchen knives (which were previously ground on my small bench waterwheel) and too coarse for most of my carving tools. I expect Ben Orford's recommendation: a King 1000/6000 combination stone, would be a better choice, at about twice the price . I made a false economy but the stone will find a use & I need more time to get used to it. The 1000 grit water-stone seems equivalent to the coarse side of my Draper oil-stone. BTW I really like my Draper combination oil-stone now and it sees a lot more use than it did previously.

I've also got one of the above wooden boxes my father's very fine-grit old stones - an old natural stone I think, it was yellow when I cleaned it but is rather black again now. It is noticeably finer than the fine side of my Draper combination stone - so I can now use a 3-stage oil stone sharpening process, if I feel the need: Draper coarse -> Draper fine -> Pa's very fine natural stone
Alternatively: Waterstone 400 -> Waterstone 1000 -> Draper fine -> Pa's natural stone.

[SeanHellman]

What is pa's oil stone?

Would be interested in seeing some pics sometime.

[gavin]

It is interesting how different folk have different preferences. I like the 1000 grit water stones - good for kitchen knives IMO. I don't mind the water and dislike the dust that oil brings with it. No problem with clearing water in the kitchen - esp on the sinik, but big problem if oil gets in kitchen.

[ToneWood]

The 1000 definitely seemed the more appropriate of the two grits. To be fair, they seemed to cut the s/steel well - which is a really important feature - indicated by black dust suspended in the water, but the result left more scratches than I have seen before (even after a 200 grit wet wheel) and the resulting edge just didn't seem as "positively sharp" as I am used to now - so I finished them off with the oil stones. Early days though, maybe I'm not using them right yet. It might also be that this inexpensive stone's 1000 is coarser than whatever brand Gavin is using. I'll persevere with them.

Sean, I'll see if I can get a decent picture but actually Pa's stone isn't much to look at: its fairly short (6"?) and very regular in shape (modern? with a corner missing). It is not one of those veined, green Charnwood Forest jobs . When I first cleaned it and used it with dishwater, this previously black block started to reveal its underlying uniform soft yellow colour (like limestone but I would guess that it is more likely sandstone). Unfortunately, since I have started using oil, it has quickly blackened again.

BTW The Tesco's baby oil doesn't create much mess: it's very thin & soaks into the stones. I wipe the blades occasionally while sharpening and I just wipe the stone once with a paper towel when done & close the wooden box. But as I said, the stones are blackening to a greater or lesser degree, so perhaps the metal offcuts are starting to build up & they might need more thorough cleaning (paraffin/kerosene/white spirit? ) later.

[ToneWood]

BTW I recently bought this combination waterstone from Amazon, it was cheap at the time:


Kitchen Craft Master Class Combination Sharpening Stone
by Master Class
...

I just sharpened a drawer full of kitchen knives with the 400/1000 waterstone - think I am getting the hang of it now. It is actually a very good combination for the kitchen, in that it allows you to quickly & efficiently re-establish a sharp cutting edge with the 400 & then quickly refine it with the 1000. Particularly good for first time sharpeners, who might otherwise become disheartened with the amount of effort required to get an edge with a stone that is too fine - or anybody looking to get the job done quickly.

It leaves a very sharp, "satin" finish [so I finished off the bigger knives with my finest oilstone & then stropped all of the knives. Not really necessary though - and might not bother with that extra work in future.] This will be my stone for kitchen knife sharpening going forward - but I will likely stick with my oil-stones for the wood tools. It's all good

BTW Just noticed the price of the above stone has now dropped to £16.52 inc. shipping. Good value - more than twice the price of a decent name brand oilstone but you don't need to buy honing oil.

[Billman]

Going back 50 years to my days as an apprentice, a cutting fluid has three principaL functions:

To reduce friction
To cool the tool/workpiece
To remove the swarf

It also may have secondary functions/effects, e.g. to reduce built up edge (where the work sticks to the cutting tool), allow an increase in cutting speed, prolong tool life..

For industrial grinding a soluble oil diluted with water (suds) was used on man made stones (never leave the suds pump running when the stone was stationary, or it could soak into the bottom half of the stone, causing it to go out of balance - with disastrous, possible fatal, results). On natural stone wheels, water was the prefered medium - as it is on japanese water stones. Hard stones such a Arkansas are also probably best used with water, or a very thn oil/kerosene (paraffin in the UK) mix..

JRC is correct that the oil on an oils stone does float away some of the metal removed, but how many of us flood the stone to that effect?? I tend to use the minimum possible..

A clogged stone can be cleaned, but the most comon problem is a hollow stone, as most of use do not use the ends of the stone very much, and even when we do, most pressure occurs at the middle of the stroke... I have several stones, keeping my best ones for plane irons - however, they do not they much use as I bought a four sided diamond bench hone at Lidyl a few years ago for under a tenner... I generally just spit on it.... as I can never find the oilcan, espcially when on site...

[ToneWood]

I thought honing oil/water is mainly for helping keep the stone clear of swarf - but, yes, the lubricating effect certainly does help maintain a good, smooth, sharpening rhythm (e.g.don't want the blade to stop suddenly part way through a sharpening stroke). I also find in reassuring to see black flecks of ground off metal in the oil/water - confirming that cutting has taken place and that at least some of the metal has been lifted away from the stone (which requires a fairly generous splash of oil/water). I also like to see the blade scraping up the oil/water in a little wave ahead of it, especially on the last few strokes. For rotating stone wheels, yes, cooling is probably a major consideration - that's why I went for a small wet grinder rather than regular bench grinder.

[tagnut69]

plain old 3 in 1 or what ever the pound shop has in when I run out, normally branded 151

[Simon Hartley]

I have been referring to the book I use: Jim Kingshott's "Sharpening Pocket Reference Book". He is quite adamant that any fluid on the stone should not be referred to as lubricant, since it is not the intention to reduce friction against the blade. However, he does just that a few pages later.

Regarding Japanese water stones, he states that a slurry of particles abraded from the stone is essential to the grinding process, therefore it shouldn't be washed off. The little 'nagura' stone is apparently to work up an initial slurry before you start.

[ToneWood]

BTW I recently bought this combination waterstone from Amazon...:


Kitchen Craft Master Class Combination Sharpening Stone
by Master Class
...

... a very good combination for the kitchen...It leaves a very sharp, "satin" finish...

I found a stone to complement my 400/1000 waterstone, above. It is 3000/8000 combination stone and is by far the least expensive I have come across with these extra fine grit ratings (£18.79 inc. shipping). Same dimensions & same rubber base. This one is on ebay and ships from Hong Kong: http://www.ebay.co.uk/itm/Water-Stone-Dual-2-Side-Whetstone-Razor-Blade-Sharpener-Sharpening-3000-8000/271514900472

I have only tried it on a couple of large stainless steel kitchen knives so far but:
a. The grits ratings seem accurate, certainly significantly finer grits than my other stone.
b. The 3000 grit stone is quite soft and very readily produces a thick pink slurry (unlike the other 3 stones), which is quite fun to use, no need for a nagura stone (perhaps it should have been baked a little longer?). Might be an issue if you are a heavy user.
c. The 8000 grit is quite hard, like both sides of the 400/1000 stone.

I just gave the knives a few passes on each side of the new stone, to just finish off the already sharp edges produced by my 400/1000 stone: it does indeed produce a shinier, smoother more refined edge but I will need to use them to get the most out of them. Pleased so far tho'.