Thread: Lapping help...

I have a carborundum double-sided hone that needs to be lapped. I have spent about 6 hours trying to get it flat and there is still a dip in the center. I have even gone down to 100 grit paper and I just can't get it to do anything. I have been tempted to put it on the belt sander, but thought that would be too extreme. The smoth side seemed to lap OK, but the rough side is the problem. Any help/suggestions would be appreciated. Thanks.

I have gone to the belt sander before, but be very careful! There's some potential to do more harm than good. 240grit on the lowest speed setting will go very fast to getting it back to flatter. I wouldn't try on anything coarser than that.

Hi Wireless,
I think you will have to invest in a DMT to do carb stone. They are really hard. I would get the xcoarse or the xxcoarse and you will have a good lapper for all your stones.
Mike

Wireless - forget the sandpaper and get some grit from a stone-tumbling/lapidary place - cuts hard stone like magic. You may want several low-grit sizes (eg 80, 150, 280 ... 600) before finishing on some finer paper, but 280 may be enough for you.

Just get a strong flat surface (thick plate glass, granite tile, etc) pour a small amount of the grit into a puddle of water in the centre of it and work the hone on it. It will frost the glass/mark the tile as well, remember.

It's messy, but you get to use wider/longer movements and it is very fast.

Regards,
Neil.

Pumice stone. The more stone you want to remove the stronger the pumice you'll need.

If you choose to go the DMT route, the XX is on sale at amazon. Atleast it was yesterday when I bought mine.

Thanks for all of your replies! Maybe I will go the DMT route and then I can have it for any othere stones. So in choosing a DMT I keep seeing the 325 grit and make sure it is biggere than my othere stones. Is this correct?

I dont think it has to be bigger, just not smaller. I went with the 8XX, which is 8" long, they also have a ten inch if you want it bigger but it seems most just go with the 8.

I'm pretty sure the D8XX is actually ~$20 MORE than it was a month ago when I bought my D8X. I got the d8X for ~$45 because it was like $10 cheaper than the XX if I remember right.


The 8x3" DMT's lap everything I own. I seem to remember eyeing the 11" but they were NARROWER than the 8" if I remember right... like 11x2.5 vs 8x3?

edit: Ah but the 10inchers are wider. Nevermind.

I guess I was wrong, they said it was on sale but according to Ians price list, I paid full price. It must of been the whole we'll mark it up then lower the price and call it a sale thing. May I ask where you bought yours IanS.

Edit: The DMT site list them for 95, amazon for 69. Maybe they have had a price increase in the last month do to the fact that demand has gone up, thanks to this forum.