Flat Laps Scratching

[xcvator]

I've got 2 diamond flat lap discs that are leaving scratches , a 320 and a 600 grit. Is there any way to "dress" these to get rid of the offending high bits. I may have cross contaminated them, is there any way to tell.   
cheers Keith

[Faceting Frank]

Who's laps are they?

[xcvator]

NFI,  Chinese ebayer's 

[xcvator]

[Faceting Frank]

Doesn't look to good, look like clumps of diamond on the lap. I can remember that happening to me once years ago, tried to pick them out with a pin. But never worked, since it was a 1200 lap and had to produce a good finish I had to scrap it.

[MakkyBrown]

I've got 2 diamond flat lap discs that are leaving scratches , a 320 and a 600 grit. Is there any way to "dress" these to get rid of the offending high bits. I may have cross contaminated them, is there any way to tell.   
cheers Keith

I'd just use the 320. You could give the 600 a good run over with a chunk of synthetic corundum.
MB

[xcvator]

I've got 2 diamond flat lap discs that are leaving scratches , a 320 and a 600 grit. Is there any way to "dress" these to get rid of the offending high bits. I may have cross contaminated them, is there any way to tell.   
cheers Keith

I'd just use the 320. You could give the 600 a good run over with a chunk of synthetic corundum.
MB

I'm new to this, where do I get this please? Is it a dressing stick ?

[steveo]

I have one or two laps that look like that also. I thought maybe it was swath. Not using enough water?

[MakkyBrown]

I was just referring to synthetic sapphire, you can buy it from lapidary sellers but you can
also buy dressing sticks(might be silicon carbide), Aussie Sapphire might sell them for dressing saw blades but I've never dressed a coated lap before and it is sort of a waste so to speak to do so. Perhaps try roughing in a few stones on the 600 and see if it settles down. You could texta the lap surface where the scratches causing areas are and don't use that area when you are close to the depth you want.

Try using the lap without any downward hand pressure(just the weight from the hand piece/stone), lots of water, and see if the scratches still appear.
But if the lumps of diamond are big and cutting deep there maybe be no hope.
Best of luck
MB

[xcvator]

Thank you