Cooler Lapping Tutorial

Have you ever looked down in the base of your computer cooler? They aren’t always clean and shining. So in this tutorial DIY, I decided to explain how to make them look like a mirror, helping to down your computer temperature. Using some basic material that almost everyone have at home and with some simple steps your cooler will get better then new! Hope you enjoy! 🙂


Material Needed




  • The principles of the cooler is to cold some heat source, for example an computer processor, it can be used on ChipSet’s, VGA chips, Northbridge, Southbridge or even in RAM memories. All those chips are cooled in many different ways, with FANs (most common ones), using water (water cooling) of just the metal par of the cooler, using the internal air to do it.

  • Many people ask why lapping, and if it helps in any way. The main reason for lapping is to maximize the contact area between the cooler and the processor (for example). Usually coolers already comes with flash base, but they’re not always well polished, and this way, having a worst contact with the heat nucleus. So the finality of lapping is to make the surface of the cooler better polished, without fictions nor imperfections.

  • The best combination for better performance is having your cooler lapped and a good thermal paste. It can lower your computer temperature and make it last long!

  • This tutorial you can use in normal Air Coolers, without fan coolers and even in WaterBlocks. This isn’t a hard job, but it may take some time to do it, and if you don’t want to do all steps, it may work as well!

  • I’ll explain how to make a cooler lapping with stuff you find at home, without any professional equipment. This way anyone can do it. In this tutorial, I’m using a WBK 38 cooler from Globalwin.






1. Lapping


    Now you’ll need some items like sandpaper (400,600, 1200), metal polish oil, toothpaste (normal white), cloth (more than one) and alcohol (For cleaning)
    Take the sand paper and fix over the glass using some tape. In this case I used the bathroom, because there is a very plan.
    Lets start lapping using a 400 sandpaper, with it we can take some irregularities off. I advise you to fix the sandpaper using some tape, so its easy to handle.
    Use water over the sandpaper and making circular movements rub the cooler over the paper, applying the same weight(not much, it may ruin the paper) so it gets equally flat.
    The base must get homogeneous, it will look very scratched.
    Do all again, but this time withe the sandpaper 600. And then after with the 1200 sandpaper, but this time keep doing longer, for 8-12 minutes. Wont be so scratched out anymore.
    Now to finish this process, put over the cloth some white toothpaste, because they aren’t abrasives, and that helps with lapping. Do it for 15 minutes, and remember to use alot of force and make circular movements.





2. Polishing


    To finish our lapping process, take the cloth and put some metal polish oil and rub quite alot, for around 15 minutes, always with circular movements. The cloth will get quite dark. In the end it will be almost like a mirror, just needing some final touch.
    The last step is to make it look lika a mirror. So you need to get another clean and dry cloth and put more polish oil, repit the last process for around 10 minutes, and then 10 minutes more. This should be the last process for lapping. The base shound look like a mirror, but it may still have some few small scratches, but those are insignificant. Usually it happens when something gets between the sandpaper and the cooler.
    Now the cooler base should be perfectly mirrored. Just some cleaning now would be nice. Using another clean cloth and alchool.
    In the end, the result if amazing, the base is like a mirror.





Some images of the work done:







I’m not sure if I was clear enought in this tutorial, maybe sometime I take a look and rewrite if needed!!
Hope you liked and anything just leave a comment!!
Thanks for reading…
And take a good look in our sponsors!! 🙂


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  2. rub the base with thermal goo to prevent oxidation but the oxidation doesnt effect the thermal properties. al oxide is the same as and anodized heatsink

  3. Ok, you are correct that a smooth surface is required for succesful heat transfer, but by polishing you are not increasing the surface area but reducing it! The irregullarities, wringles maybe in its worst calling, does increase the surface area significantly. In its bare form you are again correct that the contact artea is low. The problem with a non-smooth surface is the air inbetween, which can be considered as an thermal insulator. But if you fill the gap with fine thermal filling material, such as thermal conductive silicon, or a material with good thermal properties, you will get a much better result, as you will be utilising the increased surface area as contact area. In this respect a coarse surface with high grade contact material in between has considerable more performance. They are sellling smt with silver particles in it, and it really is the best thermal conductive material in the market around here, although it is somewhat expensive (10$ per tube).

    Nice shine though…

  4. obm the increased surface area for cooling is in the fins, not the contact surface. irregularities in the contact surface decrease the area available for heat transfer. thermal paste is great but the more area in direct contact the better

  5. I’m with OBM on this – instead of filling the small nooks and crannies with Brasso, leave them a little wrinkly and fill them with thermal compound. You ought to sand the surface down with 1500 and 2000 grit sandpaper, then wipe clean with rubbing alcohol and a lint-free cloth. Since Brasso’s thermal properties and its reactivity with thermal compounds aren’t well-established, this will give you a better overall thermal seal with the chip. Not as shiny, but much more effective overall.

  6. I think you guys are getting this the wrong way…
    The whole point here is maximizing the contact area between the processor and the cooler, those small creacks you OBM and JR want do not help to heat transfer and that is why you must use thermal goop (to fill them to ensure a better continuity between metals). And i would almost agree with the brasso stuff JR said but you get rid of it once you get the surface nice and shinny.

    Think of it as this, an even surface will conduct the same ammount of heat, and since none of us will be making mirrors out of our processors, the thermal goop will take care of making the transition from one metal to another a more even situation.

    Conducting heat through an even surface will make the heat to spread easily to the fins on the other side of the cooler and thus provoking it to be disipated away more efectively.

    I know this because i had to take away “old” thermal wax from a cooler and processor (both bought as new). I had to use a dremmel tool to take the stuff away because the P4 was running to 90 degrees celsius on heavy load. Since it was 2 am and i had nothing but household stuff around i used diaper rash cream (desitin is chemically the same as regular thermal paste, i applied a 1mm even coat between cooler and processor)… so now my rig runs since february (on a tropical country) up to 49 degrees celsius maximum and uses nothing more than air cooling and an extra fan attached to the case. I never turn it off (unless power failure) i have just had to reboot it (hey, it’s only xp).

    You might find more about this by hitting your physics books on the thermal chapters.

  7. It is unlikely this will actually improve th cooling ability of the heat sink over that of a standard heatsink thermal compound.

    The black sand paper is called wet and dry or silicone oxide paper in Europe.

    Nice polish though.

  8. Cool discussion going on here, so lets continue,

    First of all, in all the basic discussions on thermodynamics, metals are taken to be perfect conductors, this means that any kinetic energy transfer in terms of heat exchange on to the contact is free to go anywhere within the bounderies of metal. The principle of heatsink follows from this, you use a metal with large metal to air surface area to replace the relatively small surface area of the object you are trying to cool.

    But in practice, things are not so perfect. First of all, the metals used are not perfect, in fact far from it. Thus you have to resort to some tricks in the contact area. The surface resistance of the metals is considerably high when directly in touch with something. An intermediate contact material reduces this resistance. Also, since the metal in question is not perfect, a larger contact area is better for heat transfer (think of resistances in parallel). Thermal contact material also enables a better contact area filling the gaps. Once you transfer the heat from the object to the bulk of the heatsink, the transfer to the fins is almost instant (unless you are using something that is very very cheap), so no problem here up to the point where you need to circulate the air.

    The reason why I am telling “shinig/waxing” after sanding is not better than appliying a good thermal conductor mediant (Artic silver was the name I guess) must be clear now. The bad thing about standart thermal silicon is that the heat conductance is lower, and active silicon tend to oxydize due to rather unstable hybrid orbitals in time, resulting in the yucky thermal insulating thing you have to clean. The thermal paste in the stock fans of INTEL and AMD are also very good, but the silver thing is better. However, if you are using one I do not advise you to remove it unless absolutely necessary.

    Well, I also have some experimental data, the silver thingy has up to 10 C better performance compared to standart thermal paste (depends on the heatsink, on a p4 radiator, using coolmaster copper). Also cleaning and sanding old thermal paste on a heatsink (replacing with a standart new paste) has drastic improvement (56 C -> 45 C in the rather extravagant case of mine). Sanding is especially good in copper or cheap aluminum heatsinks, the thin layer of oxidization and/or protective coating is removed. Active silicon also attacks the oxidization layer.

    Hope the information is usefull.

  9. This is a cool tutorial!
    Guys, cut the boolshit. Take mesurements of your rig’s before and after temperatures and you will be amazed how good polishing really is.
    Before: 34 Celcius.
    After: 29 Celcius.
    AMD athlon XP 1900 X2 with standard AMD cooler.
    Heavy Load: 2x WinRar RARing the entire hard drive. Over 1 hour
    Before: 56 C
    After : 45 C

    So… no mather wath they say.. it realy works!
    Keep lapping!


    VIAGRA, CIALIS, PHENTERMINE, SOMA… and other pills!

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    Welcome please:


  11. um
    suppose you make it have a mirror finish.
    to have perfect contact with the cpu die, however, the two surfaces must be absolutely flat.
    if one is even slightly differently curved than the other, then they are in actualy contact in a very very small area.
    fill the area between the heatsink and the die with lead dust. it’s metal and it spreads…

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