Walkthrough On Lapping My Maze4

[d44ve]

OK, after posting up pictures of my CPU lapping I had a few requests on a walkthough on how I did it. Here is how it all happens.... its VERY simple.

First pictures here is the block straight from Danger Den. As you can see there are scatches 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 dont 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 recomend 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 isnt really needed. I just added this so people can see what they need to do to get it as shiney 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

[pbmaster]

Wow, what a work of art.

[ktr]

look at them dirty finger nails

nice work btw!

[d44ve]

Originally Posted by ktr

look at them dirty finger nails

nice work btw!

LOL, I said the same thing when I saw the picture. They were doing pretty good until I had to use the dremel to buff it out and that got all over the place LOL

[devinXkillyou]

so please explain the benefit of having the surface polished like this. Is it just to increase surface area, or more efficient heat transfer?

[DaMulta]

Nice work. Thank's for the walk thru.

This would go good in here http://reference.techpowerup.com/Main_Page

[ktr]

here is one from Wizzbangwizzard

http://forums.techpowerup.com/showthread.php?t=19

[trodas]

WOW! d44ve - could I have a question? I was never yet able to reach such shiny results... I use mostly the wet lapping and on thick flat piece of glass, 30 x 25cm big, 8mm thick one - smoked glass piece
My problem is, that once I get to the higher grit (over 800) the surface start looking more and more dim and NOT shinny. Even with 2000 grit... Could it be bad sandpaper or I just need get thru the dim surface to the shiny one? 15 mins of laping...?
Do you ever get the dim surface?

[Chewy]

Originally Posted by d44ve

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 isnt really needed. I just added this so people can see what they need to do to get it as shiney as possible and to get out all the super fine scratches

I guess thats how he got the shiny polished look, dont for get to clean the base of the heatsink with rubbing alcohol or tim remove after. right?



Thnaks for sharing, one day I will lap my heatsink... instead of buying a better one

[trodas]

Nah. Of course I cleaned up well before, but he got amazingly reflective surface even way before he used the dremel with polishing pad

When I lap with grit 2000 I get very unsatisfactory results... I mean, the surface is very dim, never nicely reflective...

[d44ve]

Originally Posted by trodas

Nah. Of course I cleaned up well before, but he got amazingly reflective surface even way before he used the dremel with polishing pad

When I lap with grit 2000 I get very unsatisfactory results... I mean, the surface is very dim, never nicely reflective...

IF you would go to 2500 grit you get a fairly reflective surface. However, the rubbing compound does the trick the best.

[TSX420J]

Sick I need to do this when I order my waterblock. Good DIY.

[KennyT772]

Guys you forget to note that having a shiney reflective surface means nothing. I have and always will advise against using a rubbing compound or polish as it will usually counter act the purpose of lapping.

Most compounds bind to the metal filling in scratches and imperfections, thus making it shiny and smooth. However, this is the thermal paste's job. No polish to my knowledge is as good at conducting heat as thermal paste.

Would you smear toothpaste or oil on your heat sink before putting it on your cpu? No because it would hamper performance. Surface polish is the same thing. Just because it is shiny does not mean it will work the best.

d44ve - A polishing pad does not remove imperfections, it only fills them in.

[d44ve]

No, I am sorry, but I am going to have to disagree with you.

I ran a car detailing company for over 7 years. The compound is a SLIGHT abrasive along with the pad that you use to apply it. The compound will in fact remove the slight scratches.

You might be thinking of a polish, which does in fact just fill in the scratches and will counter act with the thermal paste

Besides, when I am done with the compound I clean it all off with dawn soap and rubbing alcohol. That will remove and wax/polish/compound. Therefore there will be absoluty no compound left and what you see is what you get.

Thank you for you input though and I do appreciate you trying to help myself as well as others. (not being sarcastic)

[KennyT772]

Originally Posted by d44ve

No, I am sorry, but I am going to have to disagree with you.

I ran a car detailing company for over 7 years. The compound is a SLIGHT abrasive along with the pad that you use to apply it. The compound will in fact remove the slight scratches.

You might be thinking of a polish, which does in fact just fill in the scratches.

Besides, when I am done with the compound I clean it all off with dawn soap and rubbing alcohol. Therefore there will be absoluty no compound left and what you see is what you get.

Thank you for you input though.

There is the reply I was looking for. Not enough people on this forum have extensive car knowledge or general mechanical knowledge. I guess my statement should be more clear. Using a polish is bad, using a chemical abrasive is another story. I was thinking the "compound" you were referring to was no more than a metal polish.

[d44ve]

Very good point... I should make it more clear in my walkthough.

I appreciate you pointing that out!

[Wile E]

Rubbing compound, FTW!

[KennyT772]

Only thing I would be worried about is creating dips in the surface by not equally applying the abrasive..Wouldn't just a higher grit sandpaper be a more reliable way to go?

[Wile E]

Originally Posted by KennyT772

Only thing I would be worried about is creating dips in the surface by not equally applying the abrasive..Wouldn't just a higher grit sandpaper be a more reliable way to go?

It shouldn't be an issue. You don't have to use brute force with rubbing compound. Material removal will be minimal.

[KennyT772]

Now I just need to get the time to lap my xp-90 and hr-05...

[d44ve]

Originally Posted by KennyT772

Only thing I would be worried about is creating dips in the surface by not equally applying the abrasive..Wouldn't just a higher grit sandpaper be a more reliable way to go?

I thought of this very same point.... My thoughts were that the compound really wouldnt be able to make dips in the surface, unless you really stayed on one spot for a long time with the polishing pad set to 2500+RPMS. I think if you were doing it by hand, you would have nothing to worry about.

However, on a very very microscopic level .... it could leave dips and if someone would want to be on the safe side they could go to a 2500 grit or even a 3000 grit. At that point you would get a very shiny surface.

I just dont believe that the compound could really be THAT abrasive to leave dips, so long as you use even pressure and constant and even motion through out the process

[Carcenomy]

Rather than using rubbing compound, I'd look at using proper valve lapping compound - there's a big difference between roughing up the surface of a paintjob and lapping metals.

[d44ve]

Originally Posted by Carcenomy

Rather than using rubbing compound, I'd look at using proper valve lapping compound - there's a big difference between roughing up the surface of a paintjob and lapping metals.

That is true... but most people dont know what a valve is, let alone valve lapping compound!

[keakar]

you might want to point out to apply pressure only to the center and use even pressure occassionaly rotating what your lapping to avoid lapping at an angle.

i have read some heatsink companies say the surface needs slight roughness to maintain a certain amount of thermal paste between the base. is this just BS so they save $ on lapping?

[KennyT772]

it is and it isnt. with a perfect application of thermal paste a perfectly smooth cpu and base will yield the best performance, however if too much thermal paste is used, not enough pressure is exerted in spreading the paste out, or the paste is spread out over the IHS (finger in bag or credit card technique), and the lack of scratches or other gaps for the paste to fill will cause poorer performance then a standard finish.

In other words, if you know exactly how much thermal paste to use, lap. If not, stay away from the sand paper.