Overclock.net banner

1 - 20 of 34 Posts

·
Registered
Joined
·
818 Posts
Discussion Starter #1
So I am going to lap my cpu and heatsink, just three questions:
1) should I put water on my sandpaper when i lap?
2) When should I change my sandpaper to a higher grit?
3) How will I know when I reached the maxmimum point of lapping and dont go farther?

Edit: 100th post yay.
 

·
Registered
Joined
·
791 Posts
1) no
2) after 2 or 3 passes
3) when its flat, shiny helps too but a flat non mirror finish is better than an uneven mirrored one. also when you grind it down all the way to the pins (wont happen lol)
 

·
Registered
Joined
·
791 Posts
idealy, you just want to get all the copper exposed. try not to go deeper than 3/4 of the original height.

like i said, water is not required, i have not seen anyone use water when sanding either (unless they are painting) but lapping i havnt heard of it

to lap make 20 or 30 passes back and forth, rotate 90 degrees and repeat until you get back to the start. then repeat this whole process another time and move on to a finer grit; it should take a good 30+ minutes
 

·
Registered
Joined
·
1,470 Posts
Quote:


Originally Posted by shemer77
View Post

1) should I put water on my sandpaper when i lap?

Heatsink only, never with the processor -- cruising for a bruising, otherwise.

Some folks swear by water, but it's messy as hell either way -- the black **** with water, or the black dust. So I just lapped with dry sandpaper, and finished the both the heatsink and processor with some 3M rubbing compound (finer than 2000 grit), which make a shine so bright that you can watch TV from 3 feet away. Even better is if you can polish it with jeweler's compound (Fabu-luster is the best, and is used to shine gold to that mirror finish).
 

·
Registered
Joined
·
791 Posts
Quote:


Originally Posted by StarryNite
View Post

Heatsink only, never with the processor -- cruising for a bruising, otherwise.

Some folks swear by water, but it's messy as hell either way -- the black **** with water, or the black dust. So I just lapped with dry sandpaper, and finished the both the heatsink and processor with some 3M rubbing compound (finer than 2000 grit), which make a shine so bright that you can watch TV from 3 feet away. Even better is if you can polish it with jeweler's compound (Fabu-luster is the best, and is used to shine gold to that mirror finish).

i (as well as many others) are against polishing compounds as they can leave residue on the cpu and heatsink and compromise the thermal conductivity..... unless you wash them with acid
 

·
Registered
Joined
·
818 Posts
Discussion Starter #11
wait I need to polish it at the end? I thought I just rub it with isopropyl
 

·
Registered
Joined
·
791 Posts
Quote:


Originally Posted by shemer77
View Post

wait I need to polish it at the end? I thought I just rub it with isopropyl

DONT polish... just use the alcohol
 

·
Registered
Joined
·
818 Posts
Discussion Starter #13
ok, to remove my heatsink and cpu do i just like rip them off?
 

·
Registered
Joined
·
791 Posts
Quote:


Originally Posted by shemer77
View Post

ok, to remove my heatsink and cpu do i just like rip them off?

butterknife, then use the alcohol to take the thermal goo off

(no it wont damage anything, youll be lapping it anyways)
 

·
Registered
Joined
·
1,167 Posts
Quote:


Originally Posted by shemer77
View Post

ok, to remove my heatsink and cpu do i just like rip them off?

if you mean what im thinking then not a butter knife lol. you need to take the cpu heatsink off first then (there should be clips), unlock the socket to remove the cpu.

its probably a good iodea to do it after the machine has been running, the cpu fan could prove to come off easier with it warm as opposed to cold, i myslef have never had any serious issues seperating a cpu from the hs
 

·
Registered
Joined
·
859 Posts
I lap geologic specimens for a living (make microscope slides from rock).

A good way to tell flatness and readiness for next grit is to take a pencil and make an X from corner to corner. When the X is gone, you're pretty flat and ready to move to your next grit. It's actually a woodworking trick but it works well with rocks and CPU coolers.
 

·
Registered
Joined
·
1,256 Posts
Actually, the only thing that really matters is that it's perfectly flat. From my personal experience, lapping an already flat heat spreader is a complete waste of time and decreases the value of the cpu. I'm sorry I did it to my q6600.

CPU's that are concaved will certainly benefit from lapping, convexed heat spreaders probably work better than flat heat spreaders.

And yes, you can use water if you want. I've used water every time that I've done it.
 

·
Registered
Joined
·
791 Posts
Quote:


Originally Posted by Fletcher Carnaby
View Post

I lap geologic specimens for a living (make microscope slides from rock).

A good way to tell flatness and readiness for next grit is to take a pencil and make an X from corner to corner. When the X is gone, you're pretty flat and ready to move to your next grit. It's actually a woodworking trick but it works well with rocks and CPU coolers.

yea my grandpa does this, except id use permanment marker cause pencil rubs off
 

·
Registered
Joined
·
791 Posts
Quote:


Originally Posted by smokinbonz
View Post

if you mean what im thinking then not a butter knife lol. you need to take the cpu heatsink off first then (there should be clips), unlock the socket to remove the cpu.

its probably a good iodea to do it after the machine has been running, the cpu fan could prove to come off easier with it warm as opposed to cold, i myslef have never had any serious issues seperating a cpu from the hs

i think he means the thermal compound which glues it to the heatsink
 

·
Registered
Joined
·
1,470 Posts
Quote:


Originally Posted by NickOulton
View Post

i (as well as many others) are against polishing compounds as they can leave residue on the cpu and heatsink and compromise the thermal conductivity..... unless you wash them with acid


Yes, if they use jeweller's rogue (the red and white sticks with messy oils and only used for rough buffing). But I've used final polishing compounds (I help my jeweller sis out in polishing) on both the proc and heatsink, without any performance problems. The final polishing alone cleans out the residue that the sandpaper will impregnate the metal with like nothing else, and I swear by it to this day.
 
1 - 20 of 34 Posts
Top