Lapping guru's pls advise

[martman]

I have just 1 question about lapping a HS as big as a Zalman 9700...Do I try to handle the entire unit while sanding or just remove the bottom contact plate from the HS? (It appears to be removeable)

 

[WoodButcher]

I has under the impression Zalman heatsinks were flat from the get go, Have you checked it with a straightedge? Sorry, I can't tell you if they come apart, I don't think so.

 

[martman]

Yes, I've used a straight edge razor blade. There is a slight high spot near center.

 

[WoodButcher]

Unless you plan to lap the chip as well, if the high spot on the sink is very slight (convex) I would reconsider lapping. Depending on how it mates with the chip the convex sink may be a plus. To my water block, the Dtek v2 I've added an o-ring to the center which "bows the block to add more pressure over the cpus where contact is critical.


edit- If you lap one thing that will make the job much easier when you start, first chamfer or "break" the sharp edges of the contact area. using the first grit you start with, 4 or 600 sand a 45 degree angle on the edges, you don't take much, maybe 1/32 of an inch. Just enough so that it does not catch and tear the paper when you lap.

 

[mindless1]

If the bottom comes off, take it off to lap. However, I suspect the bottom is joined to the heatpipes and it is the top that is screwed onto the bottom, that the top is (or was before the fins were added) the removable part.