Request suggestions to save a dished coticule

[vgeorge]

OK gang, let me pick your brains. I have a coticule that is badly dished. I want to salvage it with minimum loss and use it.

I have several questions to you, not ever having cut stones or faced this kind of situation before.

Da Problem

So what should look like this:

actually looks like this:

Heartbreaking!

This is my tentative plan

After filling the dish and gluing a piece of wood on the flattened top surface, I am thinking of getting the cream layer cut as shown in the diagram at a rock shop. My friend Jay feels that a rock shop will be better than a tile shop, because the blades will be thinner at the former.

If all goes well, I will end up with a flat cream surfaced combo, albeit with a thinner - but usable - coticule layer, and raw material for one normal or two small-ish coticule paddles.

Questions:

1. 
   [li]Do you have a different suggestion to salvage the dished stone (ya, other than sending it to you for safe keeping )? (It is a 7" natural combo, most likely vintage.)
   [/li]
   [li]What material will you suggest to fill the dished space? In the eventual paddle(s), this material should (a) support the cream layer, and (b) in case the cream layer thins out and disappears in spots, it should be benign to a razor's edge.
   [/li]
   [li]What would be the best glue that will coexist well with wood, the fill material (to be determined) and the cream layer?
   [/li]

Thanks for your attention! :love:

George

 

[dnullify]

I would cut a little into the dished part, then take the time to lap the remaining parts down with paper or a DMT plate. that way you know you've lopped off the absolute minimum.



a few ideas for stabilizers:
-sealant silicone
-caulking
-spackle
-Expoxy

though, if you're cutting into the dished section, i don't know if you'll need to stabilize it.

Oh, right. i just realized you wanted to end up with 2 separate stones.

then again, if you cut into the dished section you get 2 good sized slurry stones.

 

[Smythe]

At 3, move the line up into the dish. You will have two thinner paddles at 4, but paddles are generally very thin anyway (no point in having a thick but short-lived paddle). However you will have a thicker Coticule layer on the combo. Plus you could use either of the paddles as a slurry stone.

This is of course amusing the dish is as deep as it appears in the diagram... not that I don't trust your judgment but... any pix?

 

[DJKELLY]

I don't have any suggestions on the cut--personal preferences to me, but Cedric's point makes sense to me. I just wanted to let you know for comparison that the tile saw I have has a 1/16" kerf at most. I don't have a clue about a lapidary saw. The hard part will be cutting the stone on edge. You will have to make a stable set-up and maybe two passes. You would need two on my saw, at least.

I love vintage hones, and have several that all perform beautifully. I promised Chris I would quit teasing him about selling me his "problem" stone that now works so well, so I won't say anything about that. I pick up a vintage stone and a razor and then go away on a ten minute mental journey someplace. The stone tells me when it is finished and I am left with a super shaving edge. My point being that all the vintage stones I have used seem to excel in tactile feedback.
Yours truly, except to Chris, Denny

 

[vgeorge]

Thanks guys, truly appreciate the suggestions.

...

a few ideas for stabilizers:
-sealant silicone
-caulking
-spackle
-Expoxy

...

Dnullify, I am now way ahead about the filler material because of your suggestions. Can I presume all these will be fairly benign to an edge if it eventually peeps through any thin spots on the cream coticule on the paddle?

...

This is of course amusing the dish is as deep as it appears in the diagram... not that I don't trust your judgment but... any pix?

...

Cedric, you are right - I have taken an artist's liberties with a sophomoric sketch. The dish is not symmetric. Plus, there are couple of serious chips, which worry me with respect to cutting along the grain. The stone is 175mm x 40mm (which makes me slightly doubt if it is really vintage - but the condition in which I got it and the extent of damage suggest it has to be). The creamy part is 10mm at its thickest, 6.5mm at its thinnest (where the dish is worst). The creamy part also seems to have two layers. Don't forget couple of serious chips. The bbw part is near perfect. :cry:

The photographs never quite do justice because of various reasons, mainly because it is difficult to highlight a three dimensional dish of a nearly white part. Here is one attempt:

Here is the other side:

... The hard part will be cutting the stone on edge. You will have to make a stable set-up and maybe two passes. You would need two on my saw, at least. ...

Denny, I greatly enjoy your digs at my friend Chris - I want start on him too, it is just that he generously sent me a strop which I had initially thought would be one of the usual, amateur kind. He sent me something that is big enough for a small child to slide down - in beautifully finished latigo, exceptionally hand crafted. He was complaining about its draw. Highly evolved aficionados may have a false sense for the draw. Me? I am not so sure the draw is highly correlated with the cleaning of the edge, and the degree of encouragement for plastic flows, etc. from stropping. But what do I know? In any event, I am waiting for the shock of the extreme generosity from the high-artisanal strop to wear off before I take on Chris. I think we could be a team.

I am going to use what I have extrapolated from your post, and go looking for lapidarist, if that is a word. 1/16th inch kerf is 1.6 mm, not trivial for the cream layer. If a lapidarist can minimize it, that will be great.

But why did you say with your saw you will need TWO passes?

Thanks, all, sincerely for all your comments.

 

[BlacknTan]

Now, this may or may not be a valid suggestion, but it might be what I would try..

Clamp strips of cardboard to the two longitudenal sides, and fill the depresion until reasonably flat with epoxy. Epoxy resin can be mixed with all kind of fillers to make it more like a cementacious product (sawedust, fine sand, you name it).
Once reasonably flat, epoxy the top to a piece of slate, then saw off the BBW and the bottom of the coticule layer is now the top with no coticule material lost.

I'll leave it to Bart and the other Associates to determine if this is a valid approach.

Just an off-the-wall idea...

 

[DJKELLY]

Denny, I greatly enjoy your digs at my friend Chris

Digs, vut are zees digs. (The .085% German I know, inside joke)

I thought that might be the stone. I have been sleeping on your quandary and have a couple thoughts. First, I know it feels like a huge dish (looks it too), but trying to make that perfect a cut will be a chore. I am not familiar with other saws, but tile saws are designed like tiny table saws and many don't need a large blade. Mine is a quality model but it only has a 6" diameter diamond blade and sliding table (the blade is stationary). Consequently, I would have to cut it once with the flattest side registered on the fence and clamped firmly; then flip the stone end for end and register the same side on the fence to make the second, through pass. It never turns out perfectly perfect even with a quality table saw and wood.

All that to say, get a large diameter saw that will make the cut in one pass.

If you cut it, that is. I'll get back to the if.

For the filler compound, around the South we have a product called "Water Rock" that is remarkably almost the same color as the yellow side of a coticule. Obviously it is mixed with water and when set it takes a cold chisel to remove. It is made for crack repair but I use it in plumbing to fill the void around a hose bib that goes through a cinder block wall. It is not as dense as concrete and can be worked, as in sanded or filed. I would work with a little to see how it performs. It sets up in just a few minutes and is completely set up in a few hours. Neat stuff, and if you can't find it I can get it to you somehow.

Now to the if. If it were me (and yes I have more than my share) I would not cut it at all. I think the dish will be eaten up by the kerf of the cut and you will be left with very thin pieces that are liable to break anyway. I would probably bite the bullet, get a big pot and lap that sucker under a dribbling tap and let the swarf fall into the pot. Put the pot on the stove and "reduce" the soup to powder. It will cake on the bottom but comes up easily with a wooden spoon or such and is really fine, almost like talc. The coticule dust is great for strop dressing and you don't feel like you are cheating using it.

I say all this from the point of view of a tiler, not a lapidarianista. They might have a wonder machine that has an infinitely thin blade and a set up to hold irregularly shaped stones that will leave a polished kerf. Unless you have access to a precision machine, you might be disappointed in the results.

Sorry for the verbosity, but it is really quite a little project you got there. I know I am not looking at the dish, so I can't make the determination, but I think we get a little too attached to the stones. Don't get me wrong, I love 'em and am especially fond of vintages, but I use the shit out of mine. I wince when someone says they won't sharpen a knife on one because it is too precious. Live a little, guys. Buy another one and give up coffee for a month. I AM NOT TALKING ABOUT YOU, whoever you are out there.

BTW, I could tell you threw the graphics together in a hurry, but no way could I do that. I have "Paint" around here somewhere. Good Luck with the stone, Denny

 

[BlueDun]

George,
have considered that

- You don't know what the boundary layer inside the rock looks like and that you may have to sand it down to get to a clean yellow stratum
- You'll end up with a very thin and fragile BBW
- The usable thickness is still limited by the narrowest part, no matter what side you come from.
- You DO risk screwing the thing up big time :scared:

What I actually want to suggest is to just sand the thing down flat. There's still plenty of yellow left and you'll end up with a beautiful and perfect natural combo. And it will last you a lifetime! Although, you may run into trouble if you insist that your grand children must also be able to use it
Seriously, I once scored two vintage combos that were much worse off than this one. They resembled a hammock much more than a razor hone. And they had quite less material left than yours. I did sand them down and ended up with two superb hones. One is still with me and one found a new home with Robin.

Cheers
BlueDun

 

[dnullify]

Yup,
based on those pictures i would concur.
Not that i yet have any experience with coticules, but i do know my way around a shop

If you do cut it, you're going to end up with two very thin slabs.
You'll loose the saw-blade's width in material (which might be hard to recover for slurry). should the weaker side break due to filler-expansion, all that material would have been wasted.

Like above stated, lap the crap outta that stone until it's flat and save the slurry. That way the remnants of the actual stone will last longer because you won't have to raise a slurry on it.


Also, i don't know of any filler that wouldn't have a detrimental effect, other than more coticule itself. Anything softer than coti, and the blade will cleave into whatever is exposed, damaging the rather fragile edge. Anything harder, assuming perfectly flush with the coti, will likely be too dense and/or abrasive and also damage the edge.

 

[vgeorge]

All good ideas - thank you - I will keep listening.

One more thing to consider. One idea was to have this cut by a gem cutter (the person, I don't have the lapidary equipment).

Guess what I got a for a quote just now? 200 USD!! I said this is not for precious or semi-precious stone. He said, does not matter - that is the price of labor.

All of this is whole new learning for me.

 

[deighaingeal]

Some people don't realize the difference between cutting and gouging

Good luck on this endeavor. If you were in my area I would just have you bring a case of beer down to the cabinet shop where I used to work. We had a granite guy who would cut almost anything for ya.

I do have to agree though about not cutting it.

 

[Smythe]

It’s probably vintage… if it was used for honing razors “today”, almost no one would allow their stone to go so dished without lapping… but close-up shots of the sides may reveal an ID… you never know.

But looking at the hone, I may have to join the others and recommend lapping.

Cutting with anything but a very thin saw-blade and a perfect setup will most likely waste more time, money (and saw blades) than lapping… and in some cases, the piece that you cut off, with the intention to use as paddles or slurry stone, could very well disintegrate as the saw cuts. Don’t get me wrong, you could still successfully cut with a perfect setup, you have little to lose.

6mm is more than generous for a couple generations of personal use… much longer for touch-up only. And believe it or not, in exactly 3 months of use, you won’t remember it was ever thicker.

 

[Bart]

I am going to side with Bluedun and others on this one.

You have to realize that the high spots on that Coticule are lost. You can lap them into dust now, or you can take the trouble of slicing it and turn it over, but that still doesn't make the "lost part" usable. Many years later, you'll arrive at the reversed hump, and the remaining Coticule will just sit there, at both ends of the hone, with some filler material in the middle.

If you're heart bleeds seeing all the nice slurry going to the drain, my advice is to find a way to safe it. (Ardennes has tuns filled with dried slurry). If you safe the lapping water, you can allow the slurry to settle, drain off the water on top, and allow it to dry completely. The powder makes a very nice sharpening paste, and it can be used on top of your Coticule, in replacement of rubbing with a slurry stone. That in itself will safe your Coticule from future wear.

But by all means, do as you please. :thumbup:

Kind regards,
Bart.

 

[DJKELLY]

Early Alzheimer's? Get him, Gerrit.

 

[vgeorge]

Thank you all - the predominant view is to lap the sucker. That should be no problem, I have a DMT extra-course stone.

No undue loyalty to the stone, except a mild affection from rescuing it from the seller who peddled it as an unbranded two-tone stone. It did not burn any hole in my wallet either.

It has been truly educational, getting response from you guys. I truly wish I could meet Gerrit and his granite guy with a case of beer. Unfortunately, not any time soon.

I am in no hurry. I will ponder it some more, and pull the trigger - whenever I have some spare time. Will bring it back to you all. Thanks again.

 

[vgeorge]

An additional question:

Does the slurry have any food toxicity? If I used my coffee filter and kitchen vessels to collect and drain the lapping liquid, will it contaminate anything?

Thanks.

 

[DJKELLY]

I don't really know, but it hasn't killed me or the cats, and we have up to our tails in it.

 

[SliceOfLife]

I think I recognize the stone. I forgot to bid on it. You didn't pay much, I say lap the sucker.

 

[Smythe]

I don't think it's toxic, but you never know where the previous owner stored it or under what conditions. But you could use a disposable paper coffee filter in a wire strainer (sieve) over a bowl… or simply rest it in the bowl and pour the slurry into the filter then lift it out and allow the water to drain (assume the disposable filter will stand up on its own when wet).

Edit: Or as suggested... allow a few hours for the slurry to settle then pour off the excess water.

 

[vgeorge]

I don't really know, but it hasn't killed me or the cats, and we have up to our tails in it.

No, that is not helpful, Dennis. You are a cat too, and cats have nine lives.

Now, can I borrow Ralfy's evil laugh, or has he got it copyrighted?

: :

Thanks, Cedric for the suggestions.

OK, I will be baaack.