Lapping ?

[MDS]

I need to lap a HS to get rid of a small pit and have been reading about some lapping jobs that some have completed. My ? is I plan on useing a spay glue on the back of the paper to a piece of glass is this good or bad idea? Also was planning on using 400 grit>800grit>1000grit>1500grit>2000grit to polish finish and of coarse all would be wet/dry paper. How important is the pattern used I was thibking of figure 8's would work best but hay I'm neew to lapping and this may not be the best way. Any idea's just shoot them my way.

[lost]

I use nice circular motions. Has worked well for me.

[SEALTEAMTHREE]

How deep is this pit? If its a 1/16th of an inch or more, you might want to look into hiring a local machine shop to take a few hundreths of an inch off the bottom with a milling machine, and then sanding it. If its a deep pit, you could be sanding for weeks.

[prexaspes]

Machine shop? I'd get a new heatsink and bring my heads to the machine shop to get milled...

[MDS]

SEALTEAMTHREE you can just barely feel it with a finger nail not very deep at all. I've got another HS/F but I was wanting to give it a try to see how it comes out.

[amdkt7]

I doubt that it need milling! In fact you would loose tension due to the reduction in size (perhaps).

I don't use glue to hold the sandpaper. I like to get the back of the paper wet enough that the paper glues it's self to the glass. It will curl up on the edges, but you will need to wash the paper several times, plus change grit several times.

If you get the back of the paper wet enough it will stick nicely to the glass, too wet and it wil hydroplane away.

I'd start with 400 grit, see how it goes. If you are not making any progress then switch down to 330 or maybe even 220. I would not go anylower than 220 as the scratches will gouge way too deep.

I also don't think that it is worth while to go above 600 grit. It's fun to make it shiney, but some experts say that it is counterproductive, as the heatsink will float on the heatsink compound.