lapping a heatsink

I found a few tuts on the net on how to do it .. I was just wondering if anyone really messed their hs up and what they did wrong


also, I know my Microcool Northpole needs lapping because there is grooves on it ... but does a Zalman7000AICu need lapping also?

 

The stock AMD heatsink almost requires lapping. I have to say I didn't do mine exactly as most guides say. I used a sanding block but not glass, until the last 2 grit stages, then I used a flat surface block (used for marking out).

Unless you sand a slight slant on it, there isn't much danger in it, even if you do it wrong (like I did...) you will usually still get good temperatures, unless you don't clean it properly after the last sanding.

 

It isn't worth the time and effort. You may shed a (very) few degrees.
If you want to dissapate a couple of degrees, remove your mobo and drill out where the cpu would sit on the chassis then fit a fan on your side casing in the same area.
've been looking at 'thermal grease' and it is identical to grahpite grease which costs £5 for 200ml, If you have gone to the trouble of lapping your heatsink then a few drops of 'any old oil' will be as good as thermal grease...

 

Explain further, please. You've confused me.

 

that's interesting ... Im using a stock AMD heatsink on my cely .. I didn't lap it ... but it works fine ... Im thinking it work work even better had I lapped it but I didn't know how to do it back then

another thing Im using Nanotherm PCM+ Aqua and that stuff is really thin .. so I do need a really flat surface for good contact

 

I lapped two heatsinks, one aftemarket and one stock amd. The amd was concave so the contact could not have been very good with cpu. The aftermarket one was not so bad. As far as temps did not notice much of a drop, maybe a degree or so but if someone wants to spend a little time to do it go for it. I lapped it down to 2000 grit wet sandpaper, did it on the kitchen counter which was as flat a place as any i could find.

 

do you mean use a dremel on the aluminum sheet that the mobo mounts on, to cut a hole underneath the CPU and the right side casing and put a fan there?

 

Exactly that - I have a 60mm fan running there
Allegedly Intel has started fitting cooling on the reverse side of their mobo's in that area...

 

what kinna dremel bit did you use? im doing something similar with HDD but the ppl at my hardware store are retarded

 

I used a cordless drill and a 4mm bit to drill an ouline of the area I was cutting out then used snips to cut the little bits remaining - It was never going to be seen so I never bothered tidying it up

 

You could always use a hole saw, much quicker but much more expensive. I'd get a 55mm holesaw to sort a blowhole out for a 60mm fan, that way you get enough to finish it off so its not razor sharp.

I'd also get some nuts+bolts to mount the fan with, and also a drill bit to match the size

 

here's the result if anyonesinterested: (i didn't polish it .. cause wax i hear aint too good)

 

Looks like a nice lapping job. Let us know what effect the job had on your CPU temps.

 

If you want to polish it you can use Mother's Polish to shine it up, then clean it off with rubbing alchohol to remove any residue. You really aren't wanting to "polish" it as much as clean it & Mother's Polish will do just that

 

actually that's my northbridge cooler (Microcool Northpole) .. i didn't lap my zalman as it was plenty flat ... my NB gets about 20-25c, so it is pretty good i must say ... my only problem is the fan I put on it (Delta 40mm fan from sidewindercomputers.com) is WAY too loud ... I hadda connect the fan controler from my zalman to reduce it from 10,000rpm to 8,000rpm im thinking i could lower it still cause it's plenty cool ... it's a good combo though ... only one thing ... for a P4 2.8c ... is 40c idle and 50c load too hot? i looked around and most ppl get around 35c ... im not too worried cause im thinking the zalman was more intended to be quiet rather than cooling performance

 

I just lapped my heatsink this morning. ( bored & couldn't sleep )

 

I just lapped my heatsink this morning. ( bored & couldn't sleep ) My temps went from 41-41c @ idle to a steady 33 @ idle. I ran 3D Mark03 just to stress it out a bit & afterwards the CPU temp was only 39c. Not too shabby huh?

By the way I am running an all copper 60mm Speeze HS with a homemade aluminum 80mm to 60mm funnel & a Coolermaster Areo blower on top.

Don't know why the double post. Sowwy.

 

Good to know

I'm thinking of taking an old copper heatsink into school one day, try getting the surface grinder to it, that gives a mirror finish so long as the wheel has been dressed.