Desperate!! I need some help on polishing with a ceramic lap

[KeithBebo]

I have a big problem, I bought a ceramic from GRS about a year ago. I had polished several gravers with no problem. I ordered a new bottle of 50000 micron. For some reason I can no longer get a mirror finish. There are scratches in the gravers. I have tried different diamond same grit. Cleaned the lap, put on one spray, two and even three. I have sprayed it close from 4 inches to 12/14 inches. Tried to polish right after spray and waited for 20 min. I have cleaned the lap with two different acids. Now to top it off GRS even sent me another lap to try, only to get the same results. Can anyone give me any help. I also have tried several different gravers.
Thanks
Keith

 

[Donny]

What type graver are you trying to polish? HSS? Glensteel?....are you polishing the face the heels???

What is holding the gravers while you polish?

Donny

 

[KeithBebo]

I use the GRS Dual angle fixture, Lindsay Templates. Gravers I have tried HSS, M-42, Carbaltxd, Glensteel. Sorry I forgot to put that in. I have tried to polish face and heels.

 

[Sam]

I use the ceramic lap without the diamond spray and then pull the sharpened graver across a piece of tooling leather treated with the diamond spray.

 

[mrthe]

i have recently buy the new en-sharp , and the past week i have make a test and work, i use a CD (compact disk yes this ones that you use grab data) like a lap charged with 50000 diamond paste and work perfect

 

[Tira]

I'm with Sam. If I am polishing carbide (C-max, etc.) then I use the diamond spray charged on one side of my ceramic stone. If I'm using HSS or other non-carbide type material I use the other side of my ceramic wheel that is not charged with the diamond spray. I marked the side of the diamond wheel with a sharpie to indicate which is the "charged" side.

As for "charging" the wheel, too much diamond will not work. Clean the wheel with water and dish soap, dry it off and put on the sharpener. Turn on sharpener so it is spinning. Make sure you have shaken the diamond spray to evenly disburse the diamond in the solution. Spray one burst of the spray while holding about 4-6 inches above the wheel while it's turning. It will not coat evenly with that burst, but don't keep putting more on. Get a tissue (it works better than a paper towel). Right after you spray the wheel hold the tissue on the rotating wheel and smear the diamond around. It won't matter if it is not exactly everywhere. The tissue will absorb the excess and will allow what is left to work properly.

One other note. If you are trying to polish especially the face of the tool you will need to go from the 1200 (or whatever is before the diamond wheel) right to the diamond wheel. Don't change any of the angles between the coarser wheel and the diamond or it may not line up properly. It doesn't sound like you are doing this, but if you did the face - then worked on the heels - then went back to the face on the diamond you probably won't have exactly the same line up as you did with the coarser wheel.

 

[Sam]

Good points and I'm glad you mentioned the diamond side of your ceramic lap, Tira. I don't know if it's just me, but for some reason carbide seems to sharpen better with a fluid surface on ceramic (diamond spray, lamp oil, etc). Without it, I always get a sawtooth edge on my carbide gravers.

I don't use ceramic to polish carbide since I started using a cast iron lap charged with diamond spray. That seems to work fantastically well. But I only use it when I'm seeking the ultimate brightcut graver. For general work the ceramic lap and leather pad are the last steps in my sharpening.

 

[Marcus Hunt]

I'm with you on the carbide=cast iron lap Sam; much better than ceramic on carbide.

With the ceramic hone I've always found it difficult to get a mirror shine immediately after charging the lap. I tried washing it to no avail but now find as I use it more often the easier the polish comes. I also try not to wash it unless absolutely necessary (it's a bit like a seasoned wok or cast iron frying pan - you should never was these with detergent). My 1200 lap rarely gets washed/cleaned either as I find it gives a much finer whet than straight forward diamond.

 

[KeithBebo]

Thank you for the help. I will back up and start over. I know it is something I am doing.
Thank you all very much.

 

[KeithBebo]

When you use the cast iron how do you charge it? With paste or spray and wipe off as Tira said.

 

[Jim P]

The only reason that running your gravers on a lap no mater if its ceramic or cast iron will scratch them is for some reason there is contamination on the lap surface with something that is hard enough to cut the graver material and is large enough to match the size of the scratch. If the lap surface is clean when you charge it and it then scratches your gravers then the only thing that can be happening is your contaminating the lap surface with something thats not what you want on it. Im betting your diamond spray is contaminated and needs to be replaced.

 

[Mike Cirelli]

The cast iron lap is the best for carbide. When I polish tool steel on the ceramic lap I spay on the diamond spray use a folded tissue wipe it clean until dry. This usually takes a couple swipes across the wheel changing to a clean spot on the tissue. This will give you a mirror finish on your tool steel gravers.

 

[tim halloran]

Keith: With Ceramic Lap Just Spray On The Diamond ,After Cleaning Lap With Dish Detergent Or Scouring Compound.Let Dry Overnight,Then Use Lap. A ceramic Lap Does Not Absorb The Diamond It Only Rides On Top Of It. It's Like Buffing Metal With Compound, You Charge The Buff And The Compound Does The Polishing, Not the Muslin Wheel.With An Iron Lap You Spray The Diamond On The Surface Drop On A little Olive Oil And Turn On The Hone And Use a Piece Of Scrap Carbide To Work The Diamond Into The Surface Of The Lap. Diamond Is A Lot Harder Than The Iron Lap, So It Embeds Itself Into The Iron Lap. Try Using A Little Alcohol On The Surface Of The Iron Lap To Lubricate It And Help It Cut Better. Ceramic Works Better For Polishing High Speed Steel And I Put The Final Polish On Carbide With The Iron Lap. You Wont Believe How Sharp Your Tools Will Get, Carbide That Is , With The Iron Lap. It Will Make Your Life As An Engraver A Lot Easier!

 

[Dave London]

For a non power way use 3M micro lapping film, pink color Rio grande carries it. I use it on top of a glass plate . With the Lindsay templates

 

[Red Green]

Keith,

I have yet to build myself a power system, I use mrthe’s suggestion, the non-printed side of an unwanted CD. It seems to take hold of the diamond paste immediately and polishes cobalt gravers in a short time, even by hand. Thanks again mrthe!

Bob

 

[rod]

The ceramic lap is acid resistant, most of what might be contaminating it is not acid resistant.

After cleaning in the usual way with water and detergent, and or acetone, etc., I have had success with wiping the surface...outdoors...with a little nitric acid on a cotton swop, or Q-Tip. Quite quickly the cotton swob turns black as it dissolves contaminants from the surface, probably metals grains. Eventually the blackening of the acid dipped swab ceases. Run water over the ceramic lap to dilute and clean the lap. In my case, much of the discoloration that was on the lap is now cleaned off, and the lap ready for recharging once more. Nitric acid is composed of the building blocks of life ....it is HNO3. It is stingy because it has interactive energy, and can dissolve certain metals like iron. Once it is neutralized it is plain old H and N and O. Baking soda, or ammonia will neutralize it, as an after wipe. Do not pour a glass of Nitric acid into a glass of ammonia, that would be explosive, so just be sensible, like do not put a match to gasoline. True, in dissolving iron on the surface of the lap, a very tiny amount of nitrous oxide is created, this is not good to breath, but done out doors, I have found the procedure safe. I have used nitric acid to stain some the wood flutes I make for the last forty years. Perhaps other acids would clean the lap equally well?

Rod

 

[KeithBebo]

Thank all of you for all of the help, because of all the great comments, I am now polishing the gravers with great success. Where do you get the Nitric acid and does it come in different strengths, if so what strength do I need?

Thanks to all of you
Keith

P.S. Is there a way to keep this thread as I am sure it would sure help others?

 

[rod]

Where do you get the Nitric acid and does it come in different strengths, if so what strength do I need?

Anyone wanting small amounts of nitric acid, full strength industrial grade is fine, and who lives in the USA can contact "Shape Product", Oakland California... they will sell a small 500cc

bottle and ship by UPS:

Tel: 510-534-1186

 

[Arnaud Van Tilburgh]

I have been talking to Chris DeCamillis, as he told me he was the one who came up with the idea for the cast iron lap for carbide gravers. His first prototype he made out of a frying pan he told me.
Later he ordered different kinds and experimented until it was perfect.
Then he sold the idea to GRS. The idea using the cast iron lap sure wasn’t new, Chris had this idea when he watched a diamond polisher using a large one for polishing diamonds.

When you watch his Bulino DVD, he shows how he is polishing carbide gravers on a cast iron lap, not adding diamond spray but using Methanol in a spray to have a higher finish of the face.

Chris also taught me that too much spray on the ceramic lap doesn’t polish steel gravers so well.
For HSS gravers I do not ad spray, just use the dried one that is on the lap.

arnaud

 

[Mike Cirelli]

Your right Arnuad. To much spray will not polish the graver. That's why I use a tissue after spraying and while it's running to wipe the excess with a tissue.
Chris came up with a great idea with the cast iron lap. I just wish there was an easy way to resurface them. I have a few gouges in mine that I have to work around. The finish that the iron lap puts on carbide is wonderful, you don't get the micro ragged edge.