Oil Stone Cleaning - how to?

Messages
109
Location
Edinburgh
char-clean-2-png.1673

Any ideas on leeching oil out of a stone or additional stone cleaning methods / tips

So I got this "Charnley" stone, which may or may not be a legit finisher, but I got it down to a single figure price which - for me - means it's worth finding out. If it's not, at least it should finish my chisels nicely (or keep a pile of papers in place with the window open). It'll need a lot of truing, lapping, chamfering & polishing (up to 1k ish?) with wet 'n' dry paper and microfinish films, but I like doing that sort of thing.

As you can see from the first photos, it was pretty oily. I wanted to be gentle with it, so after a few hours with a brass brush & some elbow grease, it's cleaned up pretty well. There is still some surface oil to be removed (another hour or so with the brass brush), but what I really want to know is: How to leech out the oil in the stone? Lapping etc will remove some of the oily layer, but I'd like to get as much as possible out before that.

So far suggestions include:

My brother-in-law told me of a popular Scandinavian method to turn an oilstone back to a water stone, involving soaking it in very hot water and detergent for at least 24 hours, until oil leached out to the surface, then repeating this process 4 or 5 times.

Others were:
"soak it in WD40",
"Put it in the dishwasher",
"Burn the oil out" (!?!),
"Soak it in white spirit/paint thinner or charcoal lighter fluid",
"Boil it with a rag in dishwasher detergent",
"use oven cleaner and an SE razor blade" and so on.

What kind of preparation would you do?

charnley-2-jpg.1669
char-clean-1-png.1670
charnley-1-jpg.1671
 
Last edited:
char-clean-2-png.1673

Any ideas on leeching oil out of a stone or additional stone cleaning methods / tips

So I got this "Charnley" stone, which may or may not be a legit finisher, but I got it down to a single figure price which - for me - means it's worth finding out. If it's not, at least it should finish my chisels nicely (or keep a pile of papers in place with the window open). It'll need a lot of truing, lapping, chamfering & polishing (up to 1k ish?) with wet 'n' dry paper and microfinish films, but I like doing that sort of thing.

As you can see from the first photos, it was pretty oily. I wanted to be gentle with it, so after a few hours with a brass brush & some elbow grease, it's cleaned up pretty well. There is still some surface oil to be removed (another hour or so with the brass brush), but what I really want to know is: How to leech out the oil in the stone? Lapping etc will remove some of the oily layer, but I'd like to get as much as possible out before that.

So far suggestions include:

My brother-in-law told me of a popular Scandinavian method to turn an oilstone back to a water stone, involving soaking it in very hot water and detergent for at least 24 hours, until oil leached out to the surface, then repeating this process 4 or 5 times.

Others were:
"soak it in WD40",
"Put it in the dishwasher",
"Burn the oil out" (!?!),
"Soak it in white spirit/paint thinner or charcoal lighter fluid",
"Boil it with a rag in dishwasher detergent",
"use oven cleaner and an SE razor blade" and so on.

What kind of preparation would you do?

charnley-2-jpg.1669
char-clean-1-png.1670
charnley-1-jpg.1671
Referring to my trusty "Sharpening:The Complete Guide" by Jim Kingshott, the advice for dealing with a clogged stone is this, and I quote:-
"The old remedy, and one that I have never known to fail, is to boil the stone. This needs to be done carefully if the stone is not to be damaged."

To precis his advice, you find a pan big enough to lay the stone in flat, with a piece of rag underneath to support it i.e. not in direct contact with the hot metal pan bottom. Add cold water, heat and boil for about an hour. Heat softens the oil, the stone expands, and oil is forced out. Take it off the heat and allow to the whole lot to cool before removing the stone. Do NOT cool the stone with cold water, as it will crack. If the stone is in very poor condition, it may need a second boiling.

Pretty similar to your Scandinavian method.
 
I got few Charnley forests and I sometimes use them as a finisher after coticule and I find it a decent finisher. Usually Oil stone is a term used for synthetic stones and the oil penetrates into those stones, however with these natural stones I would first use a heavy duty degreaser like a brake cleaner(can be bought in a pressurized can from a car parts shop or Halfords) after that I would first soak and then wash with a dish washing liquid(fairy liquid) and this should be sufficient. After all this lap it and give it a try, they cut quite slow compared to coticule.
 
I got few Charnley forests and I sometimes use them as a finisher after coticule and I find it a decent finisher. Usually Oil stone is a term used for synthetic stones and the oil penetrates into those stones, however with these natural stones I would first use a heavy duty degreaser like a brake cleaner(can be bought in a pressurized can from a car parts shop or Halfords) after that I would first soak and then wash with a dish washing liquid(fairy liquid) and this should be sufficient. After all this lap it and give it a try, they cut quite slow compared to coticule.

That's all great advice - do you ever seal any stones?
 
Thank you very much, glad to hear that it was helpful. Also if you can transfer this question/thread to straight razor part, there are more experienced people.
No I don't sell(seal=sell?) any stones.
Seal - the way folk seal J Nats. If this turns out to be a good stone then I'll be taking it to / through temperature extremes, so sealing it with lacquer on the sides and non-honing surface might do some good.
 
Seal - the way folk seal J Nats. If this turns out to be a good stone then I'll be taking it to / through temperature extremes, so sealing it with lacquer on the sides and non-honing surface might do some good.
Sorry, never heard that term before.
I have got 3 or 4 Charnley forest stones and they are good, I mean as a finisher stone. I got one which is same colour as a coticule and I have been told that it would give better results with oil but haven't tried it. the dark blue/green ones that I got: they are slow, difficult to raise slurry but with some patience and finishing with no pressure and a final 20 lap with lather or couple of drops of fairy liquid, I can get a really good edge
 
Sorry, never heard that term before.
I have got 3 or 4 Charnley forest stones and they are good, I mean as a finisher stone. I got one which is same colour as a coticule and I have been told that it would give better results with oil but haven't tried it. the dark blue/green ones that I got: they are slow, difficult to raise slurry but with some patience and finishing with no pressure and a final 20 lap with lather or couple of drops of fairy liquid, I can get a really good edge
I had heard they were slow, but to persevere (so slow, apparently, English woodworkers used to hate sharpening chisels and gouges on them.)
 
I had heard they were slow, but to persevere (so slow, apparently, English woodworkers used to hate sharpening chisels and gouges on them.)
Yes they are proper slow, try it and be patient. Also I heard somewhere that it is not a good idea to raise slurry with a diamond stone but I did for the first 10 laps then no pressure with water and finally I use dishwashing liquid for the last 20 laps.
Good luck and tell us how you get on
 
This is the stone, dressed, chamfered and sealed (lacquered). I wanted to use both sides, but lapping the darker side revealed more and more gritty inclusions, so I went with the other side.
Honing distance is around 5 1/2 inches by 1 1/2 inches. The small hole in the centre was full of grit, so I dug that out and sanded it smooth.

All in all, I reckon it took 20 hours at the sink, but it's my first natural and any caveman would be proud of it :D .1 charn 1.jpg 1 charn 2.jpg 1 charn 3.jpg
 
This is the stone, dressed, chamfered and sealed (lacquered). I wanted to use both sides, but lapping the darker side revealed more and more gritty inclusions, so I went with the other side.
Honing distance is around 5 1/2 inches by 1 1/2 inches. The small hole in the centre was full of grit, so I dug that out and sanded it smooth.

All in all, I reckon it took 20 hours at the sink, but it's my first natural and any caveman would be proud of it :D .View attachment 20854 View attachment 20855 View attachment 20856
Hi Lord Fatboy. No doubt you've put some work into that stone. I'm a furniture maker & spend a lot of time sharpening a lot of steel with a lot of different stones but I wouldn't seal a stone. Usually it's the coarser grits that need cleaning but just leaving them unused maybe in the sun on a warm day could be enough. You'll probably find there isn't too much oil in them anyway. But if you really want to, wrap it in brown paper & shove it in the oven on a low heat for a few hours. Personally, I wouldn't bother. Getting it flat is more important. Also, try using parrafin instead of oil.
 
Back
Top Bottom