A simple question about applying thermal paste

[Ilmater]

I don't believe that applying thermal paste is such a tough thing, but I have never actually done it before. I'm installing an Athlon XP 2000+ with a Swiftech MCXC370 heatsink with Arctic Silver III thermal paste. Could someone please give me some pointers? Also, my understanding is that lapping is simply taking sandpaper to the base of the heatsink, but I hear that some people lap the CPU as well. Is this such a good idea? What grit sandpaper is best? I'm installing this stuff Thursday night, so please let me know quickly.

 

[edblor]

Hello there

Lapping is indeed sanding down the surface of either your CPU, or the base of the heatsink....or both. Use 220 grit wet/dry sandpaper. Automotive grade works great (it has a nylon back and does not tear as easily as the paper-back type). Affix the sandpaper to a very smooth surface. A glass table-top works best.

Thoroughly wet the top of the sandpaper that is on the table-top. Holding the heatsink firmly, place it on the sandpaper and make circular patterns on the sandpaper. After about 10 seconds, you will be able to see what was not "flat" about the heatsink base. Continue for about 10 minutes (or until satisfied), and you will even out any un-smooth parts.

Next up, the CPU:Q

Holding the CPU as firmly as you can (upside down!!), and making sure it does not get wet (or at least not on the delicate electrical parts), make curcular patterns with it also. With the CPU, you don't need to sand as much, and do not apply too much pressure. Let the sandpaper do the work!

Regarding the paste, a dab will do the best.

With the CPU in the socket, plop a dab, about the size of a grain of white rice, on the CPU core. Now carefully place the HSF on top. Depending on the HSF hooks, you may need to latch one side, then gently place the HSF base to the CPU, then attach the other hook.

G/L,

Edblor

 

[Ilmater]

That right there is the way I wish every one of my posts was answered. Fantastic. That's basically how I thought things should be done, but that is great reassurance. I do have one question though:

220 grit? Are you serious? I thought that the purpose was to make the heatsink smoother. 220 grit is pretty rough stuff. It's not that I would question a man who obviously knows what he's talking about, but was that possibly a typo?

 

[Viper GTS]

Originally posted by: Ilmater
That right there is the way I wish every one of my posts was answered. Fantastic. That's basically how I thought things should be done, but that is great reassurance. I do have one question though:

220 grit? Are you serious? I thought that the purpose was to make the heatsink smoother. 220 grit is pretty rough stuff. It's not that I would question a man who obviously knows what he's talking about, but was that possibly a typo?

220 is really, really rough.

I typically started out at no rougher than 400, then 600, 800, 1000, 1500, and 2000.

The end result is a mirror fine surface. I had a 12" square sheet of glass that I used for lapping, but I haven't lapped a heatsink in well over a year.

Viper GTS

 

[Ilmater]

That's more what I was expecting. When I sand wood, I only use 220 if I need to actually lose some wood. If I'm actually trying to smooth something out, I'll start with 600 and go from there. Do you wet it first as well? Anyone else have any pointers? I've heard something about using a playing card and using it to spread the thermal material across the CPU. Does anyone do that?

 

[edblor]

220 was a major typo.....D'oh-eth I says:Q

Viper is right.......and his numbers are spot on

Funny thing is, I just modded my case this past weekend. I Painted it......and I used 4 diff grades of sandpaper....220 just stuck right out. My badd

Have fun and happy OCing!

Edblor

 

[Viper GTS]

Originally posted by: Ilmater
That's more what I was expecting. When I sand wood, I only use 220 if I need to actually lose some wood. If I'm actually trying to smooth something out, I'll start with 600 and go from there. Do you wet it first as well? Anyone else have any pointers? I've heard something about using a playing card and using it to spread the thermal material across the CPU. Does anyone do that?

Put some water in the center of the sand paper, it will make the job MUCH easier. It helps keep the paper from getting clogged, and reduces friction that can catch an edge and make you rock the HS - Not something you want when you're aiming for a perfectly flat base.

Once you get to 1500 and 2000 you'll want to stop using water, at those grits you're basically polishing - It works much better when dry.

Keep in mind you must use wet/dry sandpaper, if you don't you'll make a huge mess.

For spreading paste, a playing card (or credit card) works well. You can also use a finger inside a plastic baggie, but a card produces a more even layer - and probably thinner as well.

The maker of Arctic Silver has an excellent thermal paste application guide here.

Viper GTS

 

[Ilmater]

That's a great site at Arctic Silver. Thanks.

The last questoin I have is, do I do the same grits and methods on the CPU or not?

 

[ScrapSilicon]

Originally posted by: Ilmater
That's a great site at Arctic Silver. Thanks.

The last questoin I have is, do I do the same grits and methods on the CPU or not?

do not sand on the CPU..unless you want a keychain

 

[mooseAndSquirrel]

You got great answers on "how to" but I'm still not clear on the "why to" question. I suppose it's fun and gets you into the zen of things, and maybe that's enough. But geez, just thinking about sanding my CPU creeps me out! I thought the whole idea of thermal grease was to correct for surface anomalies. I'm running CPU temps in the 30's generally.

But again, that's just me and no criticism intended. I can see how it's a craftsman's touch kind of thing.

 

[Floydian]

sanding the proc/heatsink is just so you get more contact, as sometimes there is a slight bend to the proc/heatsink, or warp, so you only get the edges/middle touching.

I know some gfx proc's were like that for sure, personally I just lap the heatsink, the proc's usually flat enough

 

[ScrapSilicon]

Originally posted by: Floydian
sanding the proc/heatsink is just so you get more contact, as sometimes there is a slight bend to the proc/heatsink, or warp, so you only get the edges/middle touching.

I know some gfx proc's were like that for sure, personally I just lap the heatsink, the proc's usually flat enough

..sand away on the core of a CPU..sand away

...as far as the HS

slight bend to the xxxx/heatsink

..that is what sanding on a pane of glass is about as the core of a cpu is unto like glass so no-sand the core..unless you want to remove the manufacturer's markings..
and want to try for
a keychain

 

[CrazySaint]

Btw, is it necessary to lap the stock Intel HSF that comes with P4s or is it flat enough?