Fastest lapping method for really bad stones..

I'm looking for the fastest possible way to lap stones. Reason: I purchased 6 crates of Arkansas stones, Of all grades. Most are junk "soft arkies" but i did get allot of black translucent and white translucent and a BUNCH of washita's Many of of which still have saw marks. I have also been picking up a wide variety of stones at flea markets/antique malls. Some of which need up to 1/8 inch lapped off...Yesterday I received a Dmt 325 (course). I quickly found out this was not very fast. I seen a DMT extra extra course 8 inch plate. But for 80$. I don't want to risk it,, and thought I better start asking the experts..

So I guess my question is. What is the fastest method for lapping? What do the commercial operations use? I have a 8 inch flat disk attached to a motor, but really that's is not any faster. And the fact that it runs at 3600 RPM. Is killing me...I keep chipping stones. I think if I can get a slower motor that might help....

Is there an advantage to using diamond? Or should I just go buy some 40 grit sandpaper from the auto body store

So far the fastest method I have found is rubbing them on the concrete porch.. :). It takes up to an hour sometimes to get past the bad spots...

Help
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I've got that DMT 120 (XX) plate and it will eat barber hones for breakfast and come back for a second helping. OTOH, with what you're up against it would be a formidable task with any manual lapping method and the plates do wear. Someone will be along with a better solution I expect. :gl:

I use my 4x36 belt sanders with a 50 grit Diablo belt to do the initial lapping on Arkies. Still slow, but fast by Arkie lapping standards.

How 'bout a belt sander? They're pretty flat and you can probably get a sanding belt with a coarse, hard compound.

There is a video of Charlie, I think, using adhesive backed sandpaper to clean up a stone quickly. It does a really good job. I'll try to dig up the vid buried somewhere on SRP once I have more coffee.

If anything it's worth the watch but it is a great idea for those ugly looking eBay hones that need a really good cleaning and lapping.

::EDIT::

I found it.

http://straightrazorpalace.com/advan...one-video.html

I have fixed a couple of dished out coticules on a belt sander. I've never tried it with an Arkansas.

If you don't have the ability to wet-sand with a belt sander, make sure you either have dust control or move the sander to a well ventilated area, and wear a respirator. They make a lot of dust.

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Originally Posted by HNSB

I have fixed a couple of dished out coticules on a belt sander. I've never tried it with an Arkansas.

If you don't have the ability to wet-sand with a belt sander, make sure you either have dust control or move the sander to a well ventilated area, and wear a respirator. They make a lot of dust.

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Definitely safety first. I personally wear a respirator whenever I use the belt sanders, no matter if its a hone or wood.. safety glasses are a must as well.:)

Crap, I don't own a belt sander. Hmmmm. My father does, sounds like its time to sweet talk him into loaning me some tools for a .....project.....

6 crates of unfinished Arkies... I don't know whether to admire you or feel bad for the ungodly amount of work ahead of you. Please enjoy either way.

I once wanted to try a piece of rock i found, but it was definitely not flat. So i made a frame to hold the stone, tied a rope to it then tied the other end to my bicycle and went for a ride on the pavement, did a very quick initial flattening! And got some exercise!

But I don't think that's what you had in mind...

Interesting... I wonder though if industry uses a planer. It would seem the fastest way to pump out flat anything. My father uses one in carpentry all the time.

For initial flatenning of bad dishes I use a good quality dry small diamond saw blade on my angle grinder. Then again used 6" wide dry linisher belt grit 40 glued to a piece of scrap granite work top. Then another belt with finer grit followed with normal wet progression of wet/dry sandpaper with water.

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Originally Posted by Pyrateknight

Interesting... I wonder though if industry uses a planer. It would seem the fastest way to pump out flat anything. My father uses one in carpentry all the time.

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They do not. At least manufacturers I have seen use horizontal disc about 2.5 metrs of diameter slowly spinning. Filled with wet sand with few bars spaced like spokes. You put hones ont that disc it gets stuck on one of the bars and sand does the jow. If you follow what one of the collegues here Margeja has made out of a bicycle it is just smaller version of it.

I can picture what your saying in my head. It would be hard but doable to make... Google turned up nothing with online videos of the hone making process. Anyone have any? Or photos?

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Originally Posted by adrspach

They do not. At least manufacturers I have seen use horizontal disc about 2.5 metrs of diameter slowly spinning. Filled with wet sand with few bars spaced like spokes. You put hones ont that disc it gets stuck on one of the bars and sand does the jow. If you follow what one of the collegues here Margeja has made out of a bicycle it is just smaller version of it.

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Useful and insightful information, i would like to see one such device. Kinda like slow motion sandblasting.

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Originally Posted by sidmind

I can picture what your saying in my head. It would be hard but doable to make... Google turned up nothing with online videos of the hone making process. Anyone have any? Or photos?

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There is a film available somewhere in archives of Czech television. Hovever there is somwhere link here showing the gadget Henk uses.

This video shows how they do it at ardennes coticule starting at 3:01
Belgian Naturel Whetstone " Ardennes Coticule " - YouTube

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Originally Posted by Theseus

I use my 4x36 belt sanders with a 50 grit Diablo belt to do the initial lapping on Arkies. Still slow, but fast by Arkie lapping standards.

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I agree but I use a smith belt from lowe's. They are ceramic. they cost 18 bucks for 3 belts but are nearly indestructable. Money well spent.
I have never used them on an arke but should work well. I have no complaints about how well they work.

im surprised no one has brought up the possibility of loose lapping grit.. havent tried it yet myself, but i think i will pick some up for a few stones..

This is interesting, google turned up the glassware hobby. And a web site that sells 8 inch diamond 3m adhesive disks. These will fit on my little disk sander...... Anyone know anything about this technology?
His Glassworks - 3M Electrostatic Diamond Disks

Still trying to figure out if diamond disks will cut faster than standard garnet(or whatever) disks. Or if they just last longer... I think the whole idea is that your sanding material has to be harder than your item...

I took a large chunk of Welch slate to a stone mason (I guess that is what you call them) in Ft. lauderdale. He cuts and polishes large stones, marble & so on,,, for all building needs. I walked in and asked if he could make a "Hone" out of the slate. I explained what a hone was to him. He said sure and walked over to a large table that had water flowing over it and blades poking through it. He shaped it in about 45 seconds, taking about 1/3 of an inch off each side. Then he walked to some brand of a wet belt sander and lapped it for me, another 30 seconds. Got home , took a pencil did my grid lines on it, DMT-325 and perfect in 5 minutes.

The mason did not even want to charge me. He had never heard of razor hones, young man of 30 years. I gave him a $20.00 anyway.

I use valve grinding compounds on a granite slab.

Give the whole bunch to a man who works with gravestones or something like that. They have to lap and polish large surfaces, maybe if you give him a lot of stuff he might do it for a reasonable price. I say this because you will have to do a LOT of work. Even with a belt sander with a flat platen and a lot of belts, that amount of stones will eat many belts, and you will have to do some grinding with hand on a diamond plate too. You will have to use the belt sander outdoors because of the massive amount of dust, and you will have to protect everything from it. The best would be a motor powered wet diamond lapping tool, but that would cost you some big money.

The minimum you should have to invest is a pack of 36 grit ceramic sanding belts, a DMT XXC, and a 400grit Atoma. I wouldn't go with a DMT8C for final lapping, because it will stick to the arkies badly, and if you do so much work, you need the best tools.

PS: if you are patient, you can skip the belt sander, and start with the XXC and see how you like it. Depends on how bad the marks on the stones are, and how much time you would like to spend in the bathroom :)

Thankyou, would you recommend the $79 XXC 8imch long one? Or would the 4 inch 16.99 XXC work for exactly the system you proposed? BTW your suggestions are exactly what I have been picturing in my head...

I think you and some of the other suggestions were great, and as always you have been most helpfull.

It depends. How big are these stones you are going to lap? Smaller stones work too, but it will be a bit slower.

Here is AM Tiger Hone being lapped for testing. I know some say you do not need to lap a barber hone but hones and stones need to be flat. Novaculite will destroy a DMT plate.
I use this big lapping block most of the time. I don’t what the material this lapping block is made out of. It feels like coral and cuts fast. After the coral block I go to the DMT extra coarse and finish on finer and finer grits until complete.
MIke

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I found a way to lap my arkys ,

My new "to me" 32 inch disk lapping table, It only required some cash and a 700 mile trip to pick it up, my wife came with me so we are making it a mini vacation which helps justify the cost.. I also purchased 50 pounds of agragate which I was told is powdered valve lapping compound (SiC) ..There is a hopper that you can't see that hangs from the ceiling which holds the aggregate then a 5 gallon bucket of water above that. The water slowly drips down into the hopper, and collects small amount of grit, then drips down into the center of the spinning disk.

Edit: I was out checking the lapper out here at the hotel, And lifted the top tray. And low and behold it is full of grinding powder. The guy I purchased this from said it was 1.50$ per pound and charged me for the 5 gallan bucket. He apparently didn't notice there was already 100 pounds still in the machine. I lucked out,

I still have to get a motor for it, but it only requires 1.5 to 2 HP


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thats cool !

You just made a lot of haddicts on SRP very jealous with that.;)

I have a spring-making company next door to my shop. They use something similar to dress the end of coil springs. They have templates into which many small springs are inserted so as to do many at one time. Seems a bit of overkill to dress stones, but HEY! Let us know how it works!

If you knew how many arky's I had to prep, you would understand.

You are definitely Boss of the Beach!

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Originally Posted by sidmind

If you knew how many arky's I had to prep, you would understand.

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OH I saw the pic! Yeah, you gotta have something heavy-duty, for sure! :D

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Originally Posted by sidmind

Crap, I don't own a belt sander. Hmmmm. My father does, sounds like its time to sweet talk him into loaning me some tools for a .....project.....

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Harbor freight has them on sale for about 30 bucks occasionally but don't use their belts, they come apart, usually upon mounting them. Loews sells the smith brand ceramic belts that last a long time and you get three for about $20
Stingray