# Lapping (sanding) IHS and Waterblock



## silkstone (Aug 11, 2019)

Hi all,

So being a little disappointed with the temps on my i7 8700k with a CM MasterLiquid lite, I decided I'd lap the waterblock on my AIO because of the horrible, rough machine marks on the copper base. While I was doing that, I decided to lap the CPU too. Below are my results.

Here's a pic of my setup. I really like the Cougar Vortex fans and have had them for a good few years. They still perform really well and are near silent.





The base of my (unlapped) waterblock. You can see the machine marks and it actually feels rough to the touch. I'm not going to go for a mirror finish on this as #1 it would take forever with the depth of these grooves and #2 I've found past 1000 grit, it really makes little difference to the cooling capacity.





To get a flat finish on the waterblock, you need a really flat surface. I'd generally just use a floor tile and tape the sandpaper down to that and move a CPU or heatsink across gently, but that's not going to be possible with an AIO so I decided to use a thick piece of scrap glass as my sanding block. It generally worked pretty well, but was slow going.





The macro on my phone camera isn't great, but I did my best to capture the progress. I started at a 400 grit, which is a little low, but will sand off a lot of the surface quite quickly. I worked my way up using 400-600-800-1000 grit doing extra passes on the 1000 grit. The process I used was to do 10-20 strokes and rotate 45 degrees before repeating until the sandpaper was dead. If I wanted a mirror finish on this, I should have spent a lot more time on the lower grits to remove all those machine marks, but my aim was just to be smooth to the touch. The end result was a very dull mirror finish with visible sanding marks, but they couldn't be felt when drawing a razor across the surface and so should have a negligible effect on cooling.










There are still a lot of visible marks on the copper, but it is a much smoother finish and a little more even as I think there were 'dimples' in the copper around where the screws are.

Next for the CPU. It's important to mask of the back of the CPU before starting, this will prevent any copper-water mixture interfering with the bottom of the CPU and also protect the corners in case of an accidental drop. I used scotch tape, but anything that doesn't leave behind any sort of residue should be fine.





The process here is similar to the waterblock, but with the sandpaper taped to a flat surface and ging up to 2000 grit (as the process takes a lot less time). Only a gentle pressure is required, enough to hold the CPU flat while moving it across the sandpaper. Any more pressure and you risk putting larger scratches in the surface than you want.





I've documented the process again, apologies for the poor picture quality, but you can clearly see that Intel CPUs are a little concave. apart from getting copper-on-copper heat transfer, my aim was to make this as flat as possible. This allows you to use very little TIM, about a grain of rice, and with adequate pressure, the TIM spreads all the way across the IHS, giving the thinnest layer possible.












The final result





You can see some lines on it still, but it is pretty smooth with a razor. It's not hard to get a mirror finish, just time consuming and I'd been at this for a few hours now and needed to wrap it up. In the past, I've never found any benefit from giving it a mirror finish apart from making it look purty.

So the results:

Before lapping, one of my cores would jump to 94 degrees pretty regularly and idle temps were pretty high.




After lapping, that core still jumps to 92 degrees, but much less frequently and average temps have dropped by around 4 degrees. Those spikes on my 'hot' core are also a lot lower than before which, in theory, should lead to a more stable overclock.





Was it worth all that time? Probably not, just for a 3-4 degree drop in temp, but if you want to make your system as efficient/overclockable as possible, then this is likely worth a try, even just to flatten out the IHS. I still need to play around a little more with the amount of TIM i'm using. In the past with lapped parts, I've found less is better. The MX-4 I am using is not very viscous and so I likely got a lot more on the chip than I really need.

On Intel CPUs you'll get a much bigger temperature drop with delidding (my next project), but that might be a little scary for some peeps. When I do mine, it will be the first time and the lack of availability of delidding kits here means I'll likely have to go slowly with a razor. I'll update this with final temps once I've done the delidding too in the next few weeks.


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## HUSKIE (Aug 11, 2019)

Poor Cpu, only 2c-4c difference.. nice lapping.


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## silkstone (Aug 11, 2019)

HUSKIE said:


> Poor Cpu, only 2c difference.. nice lapping.



I bought it 2nd hand from the US so no warranty to talk of. I'm not sure how I'd feel doing it with a brand-new chip, but it's a lot safer than delidding.


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## HUSKIE (Aug 11, 2019)

silkstone said:


> I bought it 2nd hand from the US so no warranty to talk of. I'm not sure how I'd feel doing it with a brand-new chip, but it's a lot safer than delidding.



Good luck with that. If Cpu is retail you have to check first at intel warranty before lapping. I bet there is a warranty from intel.

I rather get an decent aio. That aio isn't good to cool your shinny Cpu


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## silkstone (Aug 11, 2019)

HUSKIE said:


> Good luck with that. If Cpu is retail you have to check first at intel warranty before lapping. I bet there is a warranty from intel.
> 
> I rather get an decent aio. That aio isn't good to cool your shinny Cpu



Possibly, but I've never had a dead chip or even heard of one dying. My next step is to delid and that will definitely void whatever warranty I have!
I'm not advocating doing this. It's just something I wanted to do and thought I'd document a little of the process for the fine folks on TPU.

The AIO I have isn't really that good, but CM is really the only affordable option here for AIOs. The equivalent corsair unit is more than double the price. Before this AIO, I had a Seidon 120XL in the machine that I was quite happy with and had been using for 5+ years (and is now relegated to cooling my HTPC). When I upgraded to the 8700K (from an 8600K) I was quite surprised at the amount of heat the latest gen Intels put out!

Considering the Corsair H100i is 4x the price of this one where I live, I'm happy with the reviews. I do prefer traditional HSFs, but I really don't like the idea of a 1kg+ piece of metal hanging off my board and like the quietness of AIOs, even if they perform worse.


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## Valantar (Aug 11, 2019)

Nice job! Regarding delidding: If you are able to buy stuff from Aliexpress, there are delidding tools available there for quite cheap. No idea if they are any good, of course.


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## eidairaman1 (Aug 11, 2019)

silkstone said:


> Hi all,
> 
> So being a little disappointed with the temps on my i7 8700k with a CM MasterLiquid lite, I decided I'd lap the waterblock on my AIO because of the horrible, rough machine marks on the copper base. While I was doing that, I decided to lap the CPU too. Below are my results.
> 
> ...



Should of just delided and then used a high quality thermalpad/compound


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## TheMadDutchDude (Aug 11, 2019)

Delid it and you’ll see much better results. It’s perfectly safe to do with the correct tools.


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## silkstone (Aug 11, 2019)

eidairaman1 said:


> Should of just delided and then used a high quality thermalpad/compound



I'll be doing that too. I just ordered some CL Liquid Metal for the job. I'll look for a tool on Ali Express.

I might not get around to it for a week or 2 as it means putting my machine out of commission for a few hrs while the sealant sets.


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## micropage7 (Aug 11, 2019)

silkstone said:


> I bought it 2nd hand from the US so no warranty to talk of. I'm not sure how I'd feel doing it with a brand-new chip, but it's a lot safer than delidding.


Agree, but i never lapping IHS just the heatsink. some IHS are not flat enough to give better contact with heatsink


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## Enterprise24 (Aug 11, 2019)

Lapping Koolance 380-i in my case reduce temp by upto 10C on highly OC and delidded 8700K tested with high current load such as P95 small FFT or AIDA FPU. The waterblock is very uneven.


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## silkstone (Aug 11, 2019)

micropage7 said:


> Agree, but i never lapping IHS just the heatsink. some IHS are not flat enough to give better contact with heatsink



I've pretty much lapped every CPU I've had since my old Core 2 Duo. I've always had pretty good results and never killed a CPU. It's actually pretty easy for some alright gains. The nickel coating on the top serves little purpose. Lapping isn't for everyone, but if you're going to delid your CPU, I'd recommend lapping beforehand to get the biggest gains possible.



Enterprise24 said:


> Lapping Koolance 380-i in my case reduce temp by upto 10C on highly OC and delidded 8700K tested with high current load such as P95 small FFT or AIDA FPU. The waterblock is very uneven.



RealTemp is just measuring the max temp in my screenshots. My average temps are much better than before, but not in the 10C range


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## Enterprise24 (Aug 11, 2019)

silkstone said:


> RealTemp is just measuring the max temp in my screenshots. My average temps are much better than before, but not in the 10C range


It mean yours waterblock is already OK. Not as bad as mine.


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## jaggerwild (Aug 11, 2019)

AIO =Money grab!! 
 If you want better temps buy a pump, Res., Water block, and hose with proper Dia. You will never achieve good temps with that small of a hose, delid or not. Awesome job on the CPU, I'd suggest a good air cooler.


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## silkstone (Aug 11, 2019)

jaggerwild said:


> AIO =Money grab!!
> If you want better temps buy a pump, Res., Water block, and hose with proper Dia. You will never achieve good temps with that small of a hose, delid or not. Awesome job on the CPU, I'd suggest a good air cooler.



This was the cheapest option for the cooling potential. For reference, my AIO was $50, the lowest end Phanteks or Thermalright coolers start at the same, but go all they way up to $100 for a silver arrow.
I'd love a custom loop, but that would cost me more than my CPU! I used to only ever use air coolers, but they ended up getting so big, it became a bit worrying having that much weight on the mainboard. I like the elegance and noise levels of AIOs.


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## TheMadDutchDude (Aug 11, 2019)

The size of the hose has nothing to do with its performance, fella. It accounts for some scenarios, but not an AIO. The pump isn't exactly powerful enough to shift any mass volume of water, so the hose is perfectly fine.


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## silkstone (Aug 11, 2019)

TheMadDutchDude said:


> The size of the hose has nothing to do with its performance, fella. It accounts for some scenarios, but not an AIO. The pump isn't exactly powerful enough to shift any mass volume of water, so the hose is perfectly fine.



Yeah, the pump on AIOs is usually the weakest link. When mine goes, I might invest in a pump + waterblock to build a semi-custom loop and just reuse the radiator from this build.


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## eidairaman1 (Aug 11, 2019)

I wouldnt bother with liquid metal either, kryonaut or a high end thermalpad would be safer.


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## TheMadDutchDude (Aug 11, 2019)

There's typically very little risk to using liquid metal if you're careful enough. If you're worried about shorting under the IHS, you can always paint the surrounding area with some clear nail polish (or any color you prefer!) to avoid contact.


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## micropage7 (Aug 11, 2019)

TheMadDutchDude said:


> There's typically very little risk to using liquid metal if you're careful enough. If you're worried about shorting under the IHS, you can always paint the surrounding area with some clear nail polish (or any color you prefer!) to avoid contact.


yeah, but liquid metal is kinda risky if you don't know handle it properly


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## TheMadDutchDude (Aug 11, 2019)

Read the instructions. It’s pretty self explanatory.


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## silkstone (Aug 11, 2019)

eidairaman1 said:


> I wouldnt bother with liquid metal either, kryonaut or a high end thermalpad would be safer.



I saw that Kryonaut, or any TIM isn't as good for delidding as LM, by a fair few degrees. My plan is to use a little nail varnish on any exposed components near the die, mask off the CPU and apply a very sparing amount. I'll then make a CPU, packing foam, plexiglass sandwich and G-clamp the IHS back on with a small amount of gasket silicone in the corners.
The graphite Thermal Pads look interesting, but a also highly conductive and difficult to apply under an IHS, apparently.

My CLLU came today. Now I've just gotta wait for the delidding tool. I don't know whether I have the patience and might just try with a razor.


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## RichF (Aug 21, 2019)

Liquid Pro is extremely difficult to work with in small amounts, unless the syringe has been improved. The problem is that, no matter how softly you press, the stuff will explode out of the syringe, _over several feet_. So, my advice is to let it shoot into a clean bag and then use a lint-free brush to brush it onto what you need. Never press the syringe within five feet of your motherboard. It will shoot further than you expect.

Regular Q-tips are not lint-free. In fact, they're really terrible. The swabs that come with Liquid Pro are better but they will shed some fibers. They're not super-dusty like a conventional Q-tip but the fibers are a pain. Liquid Ultra comes with a plastic brush.


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## Nordic (Aug 21, 2019)

I am suprised to sse you had such little difference. When I lapped my 2500k and heatsink I had around a 15c change.


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## Vario (Aug 21, 2019)

Nordic said:


> I am suprised to sse you had such little difference. When I lapped my 2500k and heatsink I had around a 15c change.


The unfortunate twist in this is that his CPU was actually already delidded and then resealed, and the prior owner did a poor job.








						CPU Cooling Adventures - (fixing) a delid gone wrong
					

This thread is a continuation of the following: https://www.techpowerup.com/forums/threads/lapping-sanding-ihs-and-waterblock.258162/#post-4096571  For TLDR, scroll to bottom.  So after lapping the IHS on my 8700k and waterblock, I'd decided that I really wanted to delid too as the temperatures...




					www.techpowerup.com


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## freeagent (Aug 23, 2019)

HUSKIE said:


> I rather get an decent aio. That aio isn't good to cool your shinny Cpu



All AIOs are junk, I would stay away from them. Buying one is bad advice.


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## delshay (Aug 23, 2019)

RichF said:


> Liquid Pro is extremely difficult to work with in small amounts, unless the syringe has been improved. The problem is that, no matter how softly you press, the stuff will explode out of the syringe, _over several feet_. So, my advice is to let it shoot into a clean bag and then use a lint-free brush to brush it onto what you need. Never press the syringe within five feet of your motherboard. It will shoot further than you expect.
> 
> Regular Q-tips are not lint-free. In fact, they're really terrible. The swabs that come with Liquid Pro are better but they will shed some fibers. They're not super-dusty like a conventional Q-tip but the fibers are a pain. Liquid Ultra comes with a plastic brush.



Most if not all syringes are like that. What i have found is you twist & push at the same time either clockwise or anti-clockwise. You will now get a smooth flow of LM that will never go further than you want even on something small as HBM die.


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## silkstone (Aug 23, 2019)

delshay said:


> Most if not all syringes are like that. What i have found is you twist & push at the same time either clockwise or anti-clockwise. You will now get a smooth flow of LM that will never go further than you want even on something small as HBM die.



I updated with a second thread. I never had any problem getting the LM out, the first attempt, I just tilted it upwards and let a small bulb form on the nib. My second application though, I squeezed a small ball out and wiped it across the die. It's fine as long as you know not to squeeze too hard.


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## bmacsys (Aug 31, 2019)

silkstone said:


> This was the cheapest option for the cooling potential. For reference, my AIO was $50, the lowest end Phanteks or Thermalright coolers start at the same, but go all they way up to $100 for a silver arrow.
> I'd love a custom loop, but that would cost me more than my CPU! I used to only ever use air coolers, but they ended up getting so big, it became a bit worrying having that much weight on the mainboard. I like the elegance and noise levels of AIOs.




I have never heard of a board being damaged by a tower cooler have you? I have had several builds with Noctua and Phanteks and Thermalright dual tower coolers with even triple 140mm fan set ups without an issue.


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## silkstone (Aug 31, 2019)

bmacsys said:


> I have never heard of a board being damaged by a tower cooler have you? I have had several builds with Noctua and Phanteks and Thermalright dual tower coolers with even triple 140mm fan set ups without an issue.



Nope and I'm not arguing that tower coolers aren't better. It's as much the looks as the weight, I suppose. But, with my current build cost was a major factor. 
For reference, the Noctua NH-U12S is $80 compared to the CM AIO i have which was less than $50.

The last air cooler I had was a CoolerMaster V6, I switched to a Coolermaster Seidon 120XL and I saw the temps drop considerably (on my 2500k)


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## hzy4 (Sep 16, 2019)

never heard of lapping without doing a delid on a non-soldered chip. when you finally delid dont glue the heatspreader just secure it with socket with the clamps and you might want to lapp the corners of the heatspreader facing the chip too.


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## biffzinker (Sep 16, 2019)

hzy4 said:


> never heard of lapping without doing a delid on a non-soldered chip. when you finally delid dont glue the heatspreader just secure it with socket with the clamps and you might want to lapp the corners of the heatspreader facing the chip too.


Top was already popped.








						CPU Cooling Adventures - (fixing) a delid gone wrong
					

This thread is a continuation of the following: https://www.techpowerup.com/forums/threads/lapping-sanding-ihs-and-waterblock.258162/#post-4096571  For TLDR, scroll to bottom.  So after lapping the IHS on my 8700k and waterblock, I'd decided that I really wanted to delid too as the temperatures...




					www.techpowerup.com


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## Kissamies (Sep 16, 2019)

freeagent said:


> All AIOs are junk, I would stay away from them. Buying one is bad advice.


I have to agree, after I moved to custom loop, they feel like toys.

Can't remember when I lapped a CPU myself last time, probably my old 965 BE back in the day. Though I remember the times when lapping a Core 2 lowered temps hella lot.


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## phanbuey (Sep 16, 2019)

is this delidded?

My 8700k @ 5.1 ghz only hits about 78C-80 on package during FPU stress...

also kryonaut is much better in my experience than CM's gel.


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## ZenZimZaliben (Sep 16, 2019)

As everyone else has pointed out. Delid..it's easy. Worked wonders on several of my cpu's and my current 6700k. Last CPU I lapped was my Q9650 which did work well but it was solder so heat transfer was already pretty good.


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## biffzinker (Sep 16, 2019)

ZenZimZaliben said:


> As everyone else has pointed out. Delid..it's easy. Worked wonders on several of my cpu's and my current 6700k. Last CPU I lapped was my Q9650 which did work well but it was solder so heat transfer was already pretty good.


The OP already did. If you scroll up to my above reply there's a link you can click on.


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## ZenZimZaliben (Sep 16, 2019)

biffzinker said:


> The OP already did. If you scroll up to my above reply there's a link you can click on.


sweet


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## phanbuey (Sep 16, 2019)




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## Nordic (Sep 16, 2019)

I am seriously considering lapping my 3900x. My temps are descent in that they get to 70c in gaming and 80c in stress testing. Temperature is a big variable in Ryzens boost algorithm. I also plan on going back to watercooling again this spring.


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