I'm going to try something goofy..

What's new?

Bill Tindall, E.Tn.

David you are always trying something goofy but this sets a new bar.

Are you trying to obsolete the Unicorn?

I think it will take weeks for the shellac to dry. Might formulate it in methanol to hasten drying.

Epoxy, acrylic or hide glue might be considered.

The expensive stones are almost surely prepared from ceramic (seeded gel) abrasive particles.

Re: What's new?

David Weaver

layers - I'm thinking i'll have to sprinkle some WA (Which I'm assuming white alundum is what linde A is) and then and add shellac a little at a time. For two reasons - so that the alumina doesn't just settle in the bottom, and so that the shellac will dry.

There's a third - bubbles. Thick layers have bubbles.

As far as seeded gel and exotic abrasives that break down in stones that are supposed to be for honing, I don't really get it. I get their value in grinding, because particles stay sharp and the material sparks off instead of rowing, so the heat build up is less, but those particles that are supposedly tough but frangible to some extent for machine use usually break easily under hand pressure (expensive sandpaper belts don't last any longer than tough non-friable white or yellow alumina when lapping planes, etc).

But, you could be right. They could be fooling with exotic abrasives just to be able to say they're using them and eke a tiny improvement over another similar sized particle when the individual using the abrasive should really just be using a coarser abrasive if they need to work faster.

For example, a fine india is faster than a shapton 1000 stone on pretty much everything anyone would use, and a shapton 1000 will pin with HSS, just like a fine india does.

Trying to squeak a little bit of speed out of alumina is dopey when small diamonds are so cheap.

chief challenge number one isn't techical at all..

David Weaver

...finding a plastic tray the right size to make a hone and that can be torn/cut off and thrown away once the "hone" is done.

Re: chief challenge number one isn't techical at a

Winston

Maybe you could line an existing box with plastic wrap and pour it in there?

what does pin mean

Bill Tindall, E.Tn.

shapton 1000 will pin with HSS, just like a fine india does.

I have sharpened M2 lathe bits on India stones. In fact they are a common tool room stone.

Re: what does pin mean

David Weaver

Like pinning a file. A little piece of metal gets stuck on the surface and then scuffs and Nick's whatever goes over it.

Re: what does pin mean

David Weaver

It's more loading with the shaptons.

Re: what does pin mean

Mike In Los Angeles

If you don’t mind black, old 78rpm albums are made from shellac and dissolve in DNA. Nearly-Free shellac.

Can also be melted over heat like a burn-in stick, might be able to blend in the abrasive in a molten state. Very silly thing to try but that’s the theme, if im not mistaken. Melted shellac flakes also are nice for bonding a broken oilstone if crushed super finely.

Resist the urge to "cook" the concoction

Jim Matthews

This sort of blithe experimental alchemy turned the Malagasy suburb of Mozambique into an island. Remember, it IS 2020.

first layer

David Weaver

I found a plastic container that would be good as sacrificial and put a layer in just under 1/4th inch. The amber shellac and white alumina make for bird vomit as far as looks.

I don't think shellac will be the way to do it in any reasonable period of time (it'll be a while before this wafer dries), but did order some two part epoxy finish that has a long open time and is supposed to dry with no or minimal bubbles.

I think it'll have better surface toughness than shellac, too.

Re: Resist the urge to "cook" the concoction

David Weaver

I've burned some french polish test pieces in the burn bin. It's a filthy kind of burn!!

kind of the same filthy flamey with black smoke as a celluloid guitar pick.

Not tempted in this case, but will give it some time in the sun today to excite the alcohol out - likely result may be a crack.

alternatives

Bill Tindall, E.Tn.

There is an acrylic casting material that could work. You would be making Corian with alumina instead of whatever rock is used to make Corian. Or the styrene resin used for fiber glass. Both cure hard. Epoxy may not and if the cure is a soft plastic the result may not be a good stone.

Re: first layer

John in NM

There were a couple gem cutters who did this in the 1980's, and I forget what they called the product now. Mostly they were doing it with cerium oxide for polishing quartz (quartz is a bit tough to polish), but I think they had one with Linde A too. I've got one of the cerium laps, it worked ok but not as well as slurry.

Of course, polishing a steel edge is a completely different problem to solve.

polishing steel...

David Weaver

..which for us is relatively low quality needed, I think the following are key:

* either the stone slurries and that becomes the lubricant, the stone has air space that doesn't clog, or we add a lubricant to the surface (shellac and mineral oils are not homies, so this should work - that should also keep shellac from getting stuck to a tool by unintentional friction/heat at a tip)

* nothing in the binder more abrasive than the abrasive - not sure yet about that -we'll see. Linde A is going to be very slow cutting due to the size

* a surface that has a decent feel (oil should facilitate that even if the layer must be thin) and doesn't get seriously damaged too easily - another one yet to be seen

* decent abrasive density - 30-50% should be fine. The japanese synthetic stones are sort of in a war of abrasive density, but it's a false dilemma - if a finish stone that works at all is too slow but fine enough, then more work should've been done on the prior step.

WE'll see. I'm expecting that it may take half a dozen tries with different things to get a workable stone.

going back to 1st principals

Bill Tindall, E.Tn.

The success of this adventure will depend on the substrate. What properties do you need from the substrate for it to work? This quest should start with this question. Should it be hard? Does it need to wear away and release new particles? What's critical? Once you know the properties a polymer can be chosen to provide them.

How do you expect to improve the result embedding abrasive on the surface by dispersing abrasive throughout the material? Embedded on the surface the abrasive is easily restored. If dispersed, worn abrasive rejection and new exposure must come from wearing away the matrix . That leads to alteration of surface geometry which leads to reflattening .

I'll keep those in mind..

David Weaver

..I was thinking also that layers of the super toxic 50% solids crosslinked finish may also be good. Even the typical water based finishes with cross linker dry really hard (without it, they dry like a semi-hard plastic layer that would be cut by a chisel too easily).

The table top finish type that I ordered has a 50-70 minute working time and I get the sense that table top finish may not have been the first use. It says something about being suitable also as a glue, casting or for working with fiberglass, and for making filled resins.

Lots of options - as tiny as linde A is, the challenge is getting a usable surface that won't collect contaminants or that doesn't already have abrasive power greater than the tiny abrasive. When the epoxy arrives, I will try a 50% abrasive concentration of it by weight (which is a little bit below most resin hobbyist waterstones - they are usually more like 60 on the low side and 80 on the high side).

Re: going back to 1st principals

David Weaver

see above for reasonable conditions for a hone, but the question inside your statement (will it be better, for example, if I just had a hard layer of shellac to sprinkle Linde A on - probably not).

I expect that the surface will need abrasion from time to time with an oily diamond hone, and that shouldn't be a problem.

The desire to have the abrasive in the substrate is just for ease. Usually when I get linde A out, there's white powder somewhere other than the stone when done. It's hardly a huge contaminant given its tiny size, but it's a bit messy. Linde A on something as simple as polycarbonate may be more sensible, though. Or on yellow pine or hardwood. I tried white pine which works well as a strop, but for heavier back work, it's soft enough that the plane iron will cut it up).

testing linde A on SYP

David Weaver

Just to see what its cutting strength is. In softwood, it's almost nothing. In harder substrates, you're likely to damage or deflect the edge more than its fineness. It's so impractically slow - maybe the buffer can do something with it in a stick.

Note that even with two thicknesses, spread apart (these just come apart if I try to hold them against a container and spread them out), you can see through them.

Note also that the knot in this piece of pine (which usually breaks out of the shaving) stayed in the shaving in a perfect slice - top left of the filler container.

This is with a late type stanley plane that doesn't adjust well and I gave up before the tip of the iron was completely finished by the linde A - it's just way too slow on wood.

Dursol is very practical and within closer striking distance of this than any natural stone is.

Nothing special about the iron, either. Probably 60 hardness O1 - one of my experiments gone sideways early on - I didn't get it hard enough to be way past good file hardness - I took the advice of too many forum jockeys and tried to heat it only to low red and then quench. It achieved this hardness out of the quench and I've left it as is. The performance is identical to an iron driven past and then tempered back, at least for planing and sharpening. I've since learned to go a little past heat suggestion if working by eye (it'll never hurt the iron in one or two heats), get bonkers hard and then temper back and you can hit a really specific hardness target.

Re: what does pin mean

David Weaver

yes on the stones - anything that's not abrasive that's a little plastic is nice between stones (epoxy, shellac, etc).

Truck with the 78rpm records would be finding some here!!

I do have a couple of pounds of old shellac flakes and I'm thinking that the only way to get al-ox in the shellac without having it shrink and crack when it dries is to melt it rather than dissolve and pour.

I put this on the side for a second as lunchtime today, I made a paraffin bar of 0.3 micron linde A in an attempt to finish an edge really finely and not round much over, but not get stuck buffing by hand.

I still like the yellow stuff on the buffer best as it can follow a coarser stone, but getting a super uniform edge without rounding over and without having to do it by hand is attractive for playing.

Re: testing linde A on SYP

Mike In Los Angeles

That dursol/autosol talk reminded me of some green Master Formula metal polish I have used on MDF, no idea what micron or anything but worked fast

Re: testing linde A on SYP

David Weaver

There was a time that it wasn't as easy to find autosol in the states. I got simichrome with a banjo years ago and had an english friend who brought ten tubes of autosol with him every time he came back from europe. It was like getting a fine bottle of port from someone the way he treated them "everything else his s__t....this is what you need".

When it became available easily through e-commerce, it was like someone stole one of his trade secrets.

The inability to avoid checking everything that I have around to see what it does has led me to do far more with it sharpening than I ever did polishing (friend used it for his motorcycles).

Just about everything now is alumina except for certain specialty polishing products. If a product says it will polish steel and chrome to a scratch free surface, it'll be good for polishing the edges of tools to a shine. If it says it's good for a bright polish on steel, brass and chrome, same, but it might be even finer graded alumina.

never tried the polish you mentioned, but have used a few car wheel polishes only to find out they're mostly grease with not much abrasive in them.

Re: testing linde A on SYP

Mike In Los Angeles

Funny, the only reason I had autosol was the triumph shop near me used to get it from a german pal who would bring a box once a year. On the triumph forums they debate polishes like guys here debate dubbing, the consensus seems to be Goddards Glo, which I think has been unavailable for 40 years

The winner...

David Weaver

...always has to be something unavailable. Something that you can just get on ebay or amazon and buy is certainly not going to be exclusive enough.

On the razor boards, a stone or oxide that's readily available will always have some detrimental attribute when a label-buyer comes along. Anything can be made up. If the ultra rare is more coarse cutting then "oxides make an edge that's too sharp, and uncomfortable". If they're too uniform, then "varying particle size in uber rare stone makes an edge that no synthetic abrasive can match".

Re: The winner...

Mike In Los Angeles

It’s a shame you can’t get the real asbestos underwear, outsmarting the roadrunner just isn’t repeatable with the stuff they’re selling now