Lapping Heatsinks

Rip the Jacker

Diamond Member
Dec 29, 2004
5,415
1
76
Hey.

I just found out that you could "lap" a heatsink.

My question is, is it that necessary to get different # grits for sandpaper?

Can't I just use one type of sandpaper instead?

Would a kit be required as well?

I'm gonna try it on a Zalman CNPS7000A AlCu
 

Nessism

Golden Member
Dec 2, 1999
1,619
1
81
Most heatsinks don't need to be lapped, Zalman's included. If you have to sand, try 1000 grit, it's fine enough to be polished without too much difficulty. After sanding use some brass polish to finish up. Bare down hard at first and then lighten up as the polish starts to break down. I was able to achieve a high polished finish on a SK-7 heatsink in only a few minuets.

 

Jeff7

Lifer
Jan 4, 2001
41,596
20
81
Low-grit is used to get the surface flat, as some heatsinks have a good bit of curve to them. The high grit is for a really smooth finish to the flat surface.

If I'm in a hurry to lap a heatsink, I'll use 320 or 500 grit first, and finish off with 1500 grit. Always wet-sand too - one, it helps to prevent more scratches from appearing (I think that's why it's used anyway), plus, wet-dry sandpaper just tends to be a lot more durable than dry sandpaper. That, and dry sandpaper will come apart in water. :)