Walk Through : Lapping Your HSF

I was asked to repost this here in the cooling section.....



First pictures here is the block straight from Danger Den. As you can see there are scratches from the machining of the block. They look a lot worse in the pictures, when looking at it from a normal distance they would appear to just be slight scratches.





Next I started with a 1000 grit sandpaper. Some will start with an 800 grit and there is nothing wrong with it. The only reason why I don't go to 800 is that it is an extra step in the process and only needs to be used if there are serious defects on the surface.

I wet sanded this block since it is just a block of copper. This honestly is a step you do not have to do. You can just sand it regularly, but I am anal when it comes to this kind of stuff. Some people may want to not wet sand their CPU's. I personally have, but I used non conductive non corrosive lubricant. I have done it many times without any problems... but I would personally not recommend it for you, because I do not want to be responsible for any damage. I start by soaking the paper in water and then place it on my flat surface. I start sanding and it you start feeling it to give more and more resistance, just a little bit more water. Also, another good thing about wet sanding is that once the sand paper gets "worn" you can rinse it out and use it again.

Here are the pictures of the first pass with 1000 grit paper. As you can clearly see on the edges that this block was no where near level. This took me about 10 minutes










Here is the second pass with 1000 grit paper. As you can see it is starting to get a bit more even through the middle, but still a long ways off. This took me about another 15 minutes.









This is the third pass with 1000 grit sand paper. Getting closer, still not done yet.
Time : 15 minutes










And now this is the final pass with the 1000 grit sand paper. As you can see everything has evened out and after this is the easy part!





And now here I started with the 1500 grit sand paper, as you can see it is all starting to come together. This is the easy part. I spent about 20 minutes on this.








Now this is the pass with the 2000 grit sand paper. This is the highest I go, some people like to goto 2500 grit but to each their own. As you can see in the pictures there is only very fine scratches in the surface and already VERY reflective. This took me about 15 minutes.









Now here what I did is I took your normal automotive rubbing compound and took the dremal with a polishing pad to it. This step isn't really needed. I just added this so people can see what they need to do to get it as shiny as possible and to get out all the super fine scratches

NOTE : Do not use a POLISH. You want to use a rubbing compound. You can find this in the automotive body work section

 

Excellent post d44ve. I'd like to vote for a sticky, since I don't see any lapping guides in this forum.


Edit: just saw wizzards in the article index, but would be nice to have a stickey right in the cooling forum.

 

Very nice writeup Dave, awesome work.

 

This should have a sticky

 

i might try lapping a block someday

 

agreed nice tutorial d44ve

 

very nice should add a guide for lapping IHS on cpu

i would include pics of the lapped 3400+ i got from AthlonX2 but dont have a camer that can take good pics right now

 

I think I have that thread somewhere on here too

 

sorry to ruin this thread d44ve, but.. http://forums.techpowerup.com/showthread.php?t=31579

why didn't you just have that one moved to this section rather then make 2 threads that are almost identical..

 

that was pretty shiny wasnt it

 

its my fault, i suggested he repost it here because IMO it fits better in cooling section than in mod section

i also asked to get it a sticky here but w1zzard already had an article on lapping so they wont sticky it.

 

i meant, why didn't they just move the thread from the modding section to over here rather then have 2 threads with the same info.

 

yep great job

 

hey d44ve, care to tell us how much of a temp drop you got?

 

One question.
What do you mean by first, second, third etc "passes"

It cant just be one rub. So is it a period of time of sanding the base, a stage of shinyness or what?

 

a diferent pass means a different grit

 

No it doesnt.

 

my bad
let's wait and see what d44ve says then

 

how hard do you have to sand? lightly or hard, i mean if you took too much away would it really matter?

 

Its better to be moderate about the pressure, just let the sand paper do its job. Its a helluva lot easier to take away than it is to add or fix a screw up.

 

man if there are grooves or ridges that u can catch a finger nail in i start at like 400 or 600 grit. especially on the cheeper heatsincs as the bottoms tend to be concave. plus while it may be an extra grit to use it will actually lessen the time and work involved.

also be carefull not to rock the heatsink. and about every 50 strokes across the paper spin it 1/4 turn. and or make figure 8 patterns while sanding instead of just straigh up and back motions....

 

i believe the sandpaper is at its best for only the first 8 or 10 strokes so after that i will replace the sandpaper and switch sanding directions by 90 degrees.

i consider 2 sandings of 8 to 10 strokes in one direction then rotating your heatsink by 90 degrees and repeating for a total of 16 to 20 strokes alltogether is what makes up one "pass". it sometimes takes a few passes per grit size.

also do not push down on the heatsink when sanding or this can cause the surface to become uneven with rounded edges. just the weight of the heatsink and a slight downward pressure is enough. Rotating your heatsink by 90 degrees ensures that you achieve even surfacing as well as the added benefit of making it easy to see the progress you are making.

 

D44ve you are a god at computers my friend. Thanks for this.

 

You are just saying that so I will sleep with you, arent you??

LOL

 

i think he is, and then steal your phasechange while you're sleeping