Lathing, Sanding, Smoothing...CPU

[Susquehannock]

When reading the thread title I was confused how "Lathing" applied to a CPU.
That should be replaced with lapping, surface grinding, &/or milling.

A lathe is most commonly used for making round objects by rotating the piece along its axis.

 

[EternalX]

helpful, thanks!

 

[RotKT]

thanks

 

[josh478]

so just to clear things up before i go and ruin my cpu(hopefully not, id be ****ed) i want to dry sand the cpu? or wet sand... and if its wet sand, what about water getting on it? i mean i know you dont just hose the chip down, but what if water gets on it? i think im going to do this tomorrow, but start out with two heatsinks first just to get the jist of things.

 

[rhino56]

so just to clear things up before i go and ruin my cpu(hopefully not, id be ****ed) i want to dry sand the cpu? or wet sand... and if its wet sand, what about water getting on it? i mean i know you dont just hose the chip down, but what if water gets on it? i think im going to do this tomorrow, but start out with two heatsinks first just to get the jist of things.

there are quite a few how-tos on this subject. maybe google lapping cpu
but yes wet sand, you can get it wet just make sure its dry before you put it back in. i use dish soap as a lube to avoid chatter acrosss the sandpaper, use glass under the sandpaper.
read up on it for a bit and never be in a rush to do it. it takes time to get a good flat surface.

 

[dawei213]

Great lapping job! Though the OP had an intel chip and I can see why it is currently under the Intel CPU forum, wouldn't this be better served under the CPU >> General Discussion sub-forum? I've been looking for a thread like this for a few weeks now and didn't think to go to the Intel sub-forum.

 

[bardos]

so yeah, what about that hole in the pIV's? I used to lap P III's and heatsinks with water paper, and then wash them clean in the sink and let them dry out. So, what happens if water gets down that hole, as it will inevitably do if i use a wet method?

thx.

 

[Terranova]

sweeet thread revival anyways i tried lappin an old willimette core thingy P4 1.7 i bought some wet/dry 220 grit 600 grit and a 1500 grit. But when i got done i got the cpu down to the copper but i really wanna get it to do the mirror shine like some of you have how the heck did you do that???? anyways i got the p4 to oc to 2.3Ghz from 1.7 at 1.9 volts and it kept an idle temp of 25C so i think that aint half bad in my opinion considering my unlapped p4 2.4c northy @ 3.4 1.4vCore idles at 27-29 during summer. Would lapping make my northy temps drop? well give some input on how to get that darn mirror shine its cool lookin thanks

 

[Exempt]

holy frak! heh, for some reason a few months after I started this thread, it stopped sending me emails notifying me of new posts, anyways, I re-entered my email and I just got yours . Anyways, everyone has different methods to polishing their CPU, I always like to use the fine>finer> to finest finish of sandpaper, then a buff using "blue magic" chrome polish and a buffing wheel. Some people use drill bit buffers, but its hard to hold I imagine, both the CPU and the drill simultaneously. I use a buffing wheel, and hold the CPU firmly with my hand, the buffing wheel is mounted so I know its not going to jerk or move, accidently flinging the CPU across the room lol.

 

[Exempt]

so yeah, what about that hole in the pIV's? I used to lap P III's and heatsinks with water paper, and then wash them clean in the sink and let them dry out. So, what happens if water gets down that hole, as it will inevitably do if i use a wet method?

thx.

That hole goes under your IHS, now if you were leaving the CPU out to dry for lets say a day or so, then most likely the water would evaporate as well, since its a relatively small opening and a small cavity, so there wouldnt be a large amount of water in it, it should dry in a day or two. I would never personally wash a cpu or run water over it, I use a soft thistle or hair paintbrush, and a can of dustoff to brush the pins (or now the bga grooves) and a q-tip with some isopropyl to clean off the sides and top.

 

[dja2k]

What is the best way to sand down a pentium 4 3.0 prescott? Also, I think that the circular motion is best and not the eight figured, but this thread has people debating, so what was the best way? I have some artic silver 5, is that still good these days or not? - if not what is better? Changing my cpu setup just to have a new project to do. Hope my coolermaster hyper 6 (not 6+) still can handle this prescott core!

dja2k

 

[Exempt]

Well I have to admit, these days, I am slowing down on the whole "hardcore" overclocker, I mean, yes I still will occasionally sand a older 478, maybe a 775, but not as often as I used to. With coolers these days, even air coolers, they do a really great job of keeping the CPU cool, combine that with CPUs rolling off the shelves as "overclockable" I really don't see a point anymore. There was a time when shaving off a few degrees was a daily deal, but practicality and phase change coolers, made me digress.

If your going to do it, remember, use a flat (preferably glass) surface, hold the CPU firmly, and go in circular motion, I prefer the figure eight, forwards, then backwards, then use a fine horse hair paint brush, and dust off to remove any micro-particles that may be left behind, and if you want, again with finer and finer sandpaper, then a polish, although the polish really isn't neccessary.

 

[dja2k]

Well I got one of those new EO stepping Prescotts, so does the basic rules still stand in terms of stopping once I see the copper color? I mean, yeah these days, they try to fix the flaws in heat, but if the sanding down helps, why not.

dja2k

 

[Merlin7777]

Yeah, what about the new Conroes? Do you stop at the copper, or is there even copper?

 

[Sneaky]

same old IHS - same technique, etc. - just a different core under it

 

[Merlin7777]

Right, thanks Sneaky.

 

[Sneaky]

well... I finally said fzuckit and lapped my 920 Presler like I did with my old 3.0E Prescott, and every heatsink/waterblock that I've ever owned


My Ultra-120 and Storm G5's bases were already lapped to 2500 grit + printer paper, and they needed a good mating surface, so onto the sandpaper the Presler goes!

Ultra-120:

Storm G5:

3.0E Prescott IHS:

And my 920 Presler:

Before:

Half way through 220 grit:

After 220 grit:

 

[Sneaky]

After 600 grit:

After 1200 grit:

After 2500 grit:

After printer paper:

Reflections:

Flatness/Screen test:

Installed:

No true before & after temp results yet - still waiting for the new application of Shin Etsu G-751 to break in



Enjoy!
-JR

 

[NO1B4ME]

What do you use the printer paper for? Awesome pics

 

[ObsesivComplsiv]

Before/After thoughts...

Since no one else has brought it up .....
a true "after" pic is the surface after it has been in use, and then removed. Not to imply that yours are not flat, just that I have found that the change in that shine produced by its contact with the HS is the true "mark"(pun intended) of a job well done. Fine polishing done with a buffing wheel takes off more material than one might think. You cant get a flat surface sanding with a wheel and the same applies to polishing. Try sharpening (for knives) stones. You can incrementally remove material beyond the sanding stage and achieve a smooth and much flatter surface.