Cleaning sharpening stones

[Pekka Huhta]

I have been levelling some old oilstones, but then there are the ones that would require only cleaning. The levelled stones get "cleaned" properly, but I'm not sure about the rest of them.

For levelling the stones I have used just loose grinding paste acccumulating on the water container of my Tormek. Works way faster than any wet/dry paper or anything else I have tried.

When levelling the stones you can see clearly that there is quite a thick layer of greasy, clogged stone on the surface.

You can really see the difference between a clean stone and the clogged surface.

Even that levelling is pretty fast with the loose "tormek slurry" I would hate to scrub down all of the other stones as well just to get them clean.

How would that be done? There are instructions to use just paraffin oil and steel wool, but I doubt that would take off all the old grease or open the stone properly. Some of the stones are OLD and look like they have soaked a barrel of oil in them.

I remember reading stories about soda/dishwashwer detergent/other alkalis but I wonder what they'll do to the stone. And how they would act with the later added oil etc.

There are about 4 old India and Carborundum stones, two old Arkansas stones and one greyish natural stone that I can't figure out. Actually feels almost better than the Arkansas ones.

I'll start with just paraffin oil, but any other ideas are welcome.

Pekka

 

[Chris Knight]

Pekka,

It looks unbelievably messy!

Your greyish natural stone might be a slate. I have a couple of nice slate stones and slipstones that produce a very fine edge in the final stages of sharpening. Slate is quite easily scratched which might support such an identification.

 

[Alf]

Best info I found on cleaning them based on actual facts as opposed to "I read somewhere" is on the Norse Woodsmith site. Although I suppose that counts as reading it somewhere too... :-k Must admit I've never done it 'cos all the clogged ones I've had experience of needed flattening anyway.

Cheers, Alf

 

[Anonymous]

If you use a thin oil perhaps cut with paraffin, always wipe it off every time you sharpen, and put the lid back on, then you never need to clean the stone.
I admit to sometimes forgetting and so still have to clean them a bit if they have had long enough to dry out. I'd simply use paraffin or white-spirit alone, for the next few sharpenings.
Or I occasionally do a token flattening by rubbing one stone on another with white-spirit/paraffin but I'm not that bothered about "crazy sharpening" flatness
I wonder about using diesel fuel oil for sharpening as it's a lot cheaper than 3in1. I'll have to give it a go.

cheers
Jacob

 

[Chris Knight]

I wonder about using diesel fuel oil for sharpening as it's a lot cheaper than 3in1. I'll have to give it a go.

The purpose of a fluid used while sharpening on a bench stone is to float away the metal particles that are created by the sharpening process - that if not removed would otherwise clog the stone and reduce its cutting efficiency. The size of the particles is the principal determinant of the viscosity needed to accomplish this "floating away". The purpose of the fluid is most emphatically not lubrication (after all we need the friction to accomplish metal removal).

Thus on a very coarse stone we need a rather viscous fluid, since the size of the particles is relatively large and the traditional neatsfoot oil fits this bill rather neatly (pardon the pun..) whereas a fine Arkansas stone needs something thinner like mineral (white) spirits. Three in One is somewhere in the middle of these two extremes and thus suitable for a medium stone.

Using the wrong viscosity can lead to the stone clogging or alternatively, not cutting (as the lubrication properties overcome the cutting ability of the abrasive particles in the stone).

 

[Alf]

Using the wrong viscosity can lead to the stone clogging or alternatively, not cutting (as the lubrication properties overcome the cutting ability of the abrasive particles in the stone).

On the other hand... Mr Gorman on't matter.

Cheers, Alf

 

[mudman]

For cleaning oilstones that are hopelessly gunked up, I have successfully put them in the dishwasher. This works a treat and unclogs them nicely.
I have done this with carborundum and slate stones and it works a treat. Only two rules to remember:
1. Allow to cool naturally afterwards.
2. Do it late at night when SWMBO is in bed asleep.

I have a coarse waterstone that I've managed to contaminate with oil and am wondering if this treatment will be okay to rescue it.

 

[Pekka Huhta]

...Forgot to mention: adding a little liquid soap to the tormek slurry helps very much on the flattening. Otherwise the oil in the stone and water don't mix.

For sharpening I use paraffin oil with ¼ to ½ of engine oil mixed in it. There is quite a difference in the amount of oil: the more engine oil, the less you have to add it (and less mess you create) but adding too much slows down sharpening. Just paraffin oil is too light for me, it soaks in to man-made stones right away.

Diesel oil for the stones, ewwww. I have one stone that's been used with diesel and the smell is awful. Actually that stone is one of those I would love to de-grease. It's otherwise OK, but dirty as h*ll, full of oil, swarf, rust dirt and other unimaginables.

Thanks for the hints, the link Alf sent is probably the one I have seen earlier. I doubt if I dare to try boiling: at least one of the Arkansas stones has a thin hairline crack in it and I'd hate to pop that open. But I'll start with the "diesel-stone", it smells so bad that I won't use it anyway if it doesn't get clean. And the oil doesn't soak in to an Arkansas that bad, I'll probably survive with a surface clean on that one.

What comes to the dishwasher, I suppose wifey wouldn't object but I personally don't like the idea of grease on my plates

I remember reading a story about a man using the dishwasher for cleaning up an old engine. When wife came home, she opened the washer and found it all in there: pistons in a neat row, valves in the cutlery rack and all. Guy got that dishwasher just for himself in the garage and the family got a new one

Pekka

 

[Anonymous]

snip
Diesel oil for the stones, ewwww. I have one stone that's been used with diesel and the smell is awful. Actually that stone is one of those I would love to de-grease. It's otherwise OK, but dirty as h*ll, full of oil, swarf, rust dirt and other unimaginables.
snip

I was thinking of clean new fuel oil - not old engine oil!
The other thing about keeping stones clean is always to flood the surface with whatever fluid you use. Not just a thin smear as this will turn to paste quickly. If you flood it you can see the debris floating off as you sharpen. This is another reason for using cheap oil bought by the 5litre so you don't feel you need to skimp it.

cheers
Jacob

 

[mudman]

...

What comes to the dishwasher, I suppose wifey wouldn't object but I personally don't like the idea of grease on my plates

I remember reading a story about a man using the dishwasher for cleaning up an old engine. When wife came home, she opened the washer and found it all in there: pistons in a neat row, valves in the cutlery rack and all. Guy got that dishwasher just for himself in the garage and the family got a new one

Pekka

Doesn't seem to leave any residue. All gets flushed away nicely.

I like the engine story, I bet all that stuff was gleaming though. :lol: