diamond lapping compound

Re: diamond lapping compound

Joel

>WE use the stuff all the time with no problems (on a steel substrate) give us a call and we can try to diagnose it. 800-426-4613. try water to dilute it - not kerosene. but I don't think that's the problem. We use it straight - doiesn't gum up at all.

joel

Re: diamond lapping compound

Ted Shuck, Centennial, CO

>I've been using some 45 micron paste on a Kaneban steel plate that I bought from you (Joel). I find that it gums up for me as well unless I use some water to dilute it. I think this is just a case of the swarf building up on the plate and it needs some water to carry it away. It seems to cut very well as long as I don't let it dry out, but once it dries the swarf builds up and it will not cut any more.

After working the initial application of paste into the plate, I treat it like a Shapton waterstone and keep spritzing it with water to carry the swarf away from the surface.

Ted

Follow Ted's advice........

bill tindall

>All that metal removed from the tool, or stuff from the substrate if the substrate is harder than the tool ( a backwards situation), has to go somewhere. If it is not washed off the plate it builds up and eventually turns to thick paste. It follows that if the diamond is in water it takes something water soluble to dilute this gunk and wash it away. Water and kerosene don't mix. Follow Ted's advice and all will be well.

For cast iron I think you will find that oil based paste is preferred. Water is not much of a lubricant and I don't know when/why it would be preferred. Traditionally olive oil was used when diamonds were polished on cast iron laps with diamond abrasive.

From your description I will bet that you are charging the plates with way too much diamond. A 3 mm "worm" does a 3 x 12" plate.

Re: Follow Ted's advice........

Joel

>THe reason for the water base (The stuff isn't truly water base - it's water soluable) is for two reasons: some people are allergic to the oil base solvents - some people including me and I can't use the other stuff at all. THe second reason is that cleanup is so much easier - THe grit can get anywhere and if you do a lot of sharpening with it it's easy to get it on your hands - the water base cleans up much much better.

3 mm?

Frank D. in Montreal

>Hi Bill,

I just want to double check that because I'll start experimenting with paste soon: a 3mm worm? That's a mighty short worm...I just thought you might mean 3 cm. Sorry to second-guess you like this...

Frank

Re: diamond lapping compound

Stephen Slyke

>I can pass on what we do at work when polishing hard steels: we use diamond suspensions sold by Buehler called Metadi. There is also a Metadi fluid extender that is the same fluid with no abrasive. These fluids are kept in spray bottles.

They are "water soluble", which means the abrasive is suspended in a mixture of water and polyglycol. At the risk or boring you with the details, polyglycol is in the same chemical family as antifreeze (polyethylene glycol). This is a good water-soluble lubricant.

We always keep the diamond suspension wet including wrapping the plate in Saran wrap when we are not using it. I agree with the other posts that you need to add fluid as you work. Water may work fine for hand polishing. I don't know if adding lubricant like a few drops of dish soap in water would improve things but it might be worth a try?

-Stephen

Re: diamond lapping compound

les winter

>Thanks for the input everybody. I've got it solved now. First, I was using too much paste. I cleaned my substrate off with water and applied 1/8" of paste, which I distributed over the 2 1/2"x 8" plate.

I worked a chisel over the plate and when I saw black forming, I dropped a few drops of water on the plate and removed the black by rubbing with a paper towel. It works fine.

Thanks again everyone.

Les

I guess it is 3mm, thanks Les (sorry Bill)

Frank D. in Montreal

>

3 mm correct, on cast iron

bill tindall

>If you overcharge, carryover will be a serious issue. The frist time I charged I used 1 cm and the tool to be sharpened was so studded with embedded diamonds it sparkled under magnification. When charged one can hear the diamond cutting-skritch, skritch, etc, especially on cast iron. When the sound goes away then time to recharge. I am using what is labeled "heavy" loaded paste from MSC. Paste is available "heavy", "medium", light. On a substrate that eats diamond, eg wood, much more is necessary which is why I don't recommend a porous or soft substrate.

no need to wipe

bill tindall

>Just add lubricant and let the gunk float off the edges. If all is working properly the diamonds are embedded in the substrate and they will not float away.

Re: diamond lapping compound

John Meikrantz

>Silly question, but how do you spread the diamond paste evenly around the plate?

John

Spreading the paste

Bob Hackett

>I generally use a combination of fingers and whatever I plan to sharpen.The finger does the initial spreading while the chisel,iron,etc imbeds the diamond and gets those last places I always miss.

MB

Beware of contamination

bill tindall

>I do as Bob, but I fashion a "condom" from some thin polyethylene (eg grocery bag) to put on my finger. After smearing the paste about it can be disposed with no risk that the diamonds stuck in the finger prints will transfer to a plate with a lesser grit. I usually add a spritz of lubricant to aid spreading. While there are elaborate procedures for embedding the diamond into the plate I assume the pressure from the tool will do the trick. This could be a flawed assumption. I would like to hear more from the lapidary experts on proper charging.

Also, Scotch tape, physician's "pinky cheaters"

David Barnett - Venice, Florida

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