Thermal paste to lapping? Don't be silly...

[siravarice]

So I finally got my arse in gear the other day to sort out the thermal paste and reseat the CPU cooler. When I took it off this was what I was greeted with:

One of the pipes not really covered that well and generally there wasn't great coverage on the CPU either.

So after taking the CPU out and cleaning it, I thought, well I've got 240 grit Wet/Dry in the cupboard, why not lap it? So it all went downhill from there really....

My first session with the 240 grit stuff

This is where I notice just how NOT flat processors are. Silly Intel. After lots of rubbing I realised I didn't have a higher grit value sandpaper. So off to Halfords it was.

With all that sorted it was time to get cracking. Luckily I was watching the Grand Prix and mindlessly rubbing in circles, so it seemed like no time at all. The end product after about two hours of total sanding and rubbing, cleaning and sanding again, is this:

Notice there are still silver parts, still not flat! This picture didn't really do the finish justice, so I took it out for another one without the flash....

Temps dropped 13 degrees afterwards, and I used much better thermal paste this time. The stuff actually glitters silver.

What do people think?

 

[Steve-O-]

Your a brave man. Very brave indeed. Good stuff.

 

[siravarice]

Yeah it helps!

 

[alexhull24]

Well done, you got a really impressive temperature reduction. I was surprised how far from flat that IHS is. I've had the same thing with all my Core2 chips so far actually, lapping is probably a good idea with Intel at least, if you're not worried about resale value of course.

I also use AS5, it's a really good TIM, though if buying new I'd go for MX-3 now. Better performance and easier to apply imo. AS5 can be a bit stiff at times.

 

[tinytomlogan]

You need to get ALL the lines out of the cpu fella. go over with the 1500 LOADS more, you can get the IHS to look like a mirror

AS5 is old school now though, MX3 is way better. Ive actually started to use the Noctua stuff of late and its as good as MX3 if not better .... BUT its much easier to use

 

[siravarice]

I was going over it with 1500 for about 30 minutes Tom. I need lubrication paper, not just more rubbing with the same grit sandpaper!

 

[tinytomlogan]

Trust me fella those lines are not from the 1500

You deffo need to do the 1500 more then move on to 2000 grit. It feels like normal paper but it does work. making the cpu a bit damp helps too.

When I was a mechanic I use to polish motor bike frames and car parts in my spare time, so metal polishing si something Ive done ALOT of

 

[FragTek]

Let me see if I can find my lapping post from back in the day.... I mirror shined an A64 back in the day for my watercooled rig and it made a huge difference.

Can you removed the IHS on these new Intels? That's really the way to go....

 

[FragTek]

This is what it should look like when it's done.....

 

[pazman4]

Wow, thats some dam shiny metal, good job. :dribble:

 

[Steve-O-]

Yea sirvarice make sure the sandpaper is damp with a little water at all times and put the cpu upside-down on top of the paper and rub it around that way.

 

[FragTek]

It's also recommended to put a piece of glass down, then put the sandpaper on top of it, then start sanding the ihs upside down.... It will give you that nice shiny perfectly flat finish you are looking for.

Also don't be afraid to use the low grit stuff to take off a good amount of metal in the beginning.... These IHS's are very thick, and the more you take off the better you're going to transfer heat to your cooler rather than having it stick around inside the IHS.

You can also lap your heatsinks base. The combination of lapping both the heatsink and the IHS to a perfectly flat shine is optimal for perfect heat transfer!

 

[siravarice]

I might have to get it back out again and have another go then. But I will get some lubrication paper and get it like a mirror.

 

[Bungral]

I had a go at this a while ago on an old 939 I found.

Went pretty well in the end.

One thing I would say is that those fine scratches look like they could be caused by the already sanded debris. Thats what I found to be the biggest pain when you get down to the really fine stuff.

I also found that polystyrene worked a treat for holding the 939, shame it wouldn't really work on an Intel

 

[Rastalovich]

Any1 experienced in popping the plate off completely ?

 

[I Hunta x]

Any1 experienced in popping the plate off completely ?

From the few ive tried (old fried intel ones i for some reason kept after fixing random pc's over the years) all turned out realy badly, ended up snapping the actual core platter bit mainly, best i got was using a dremmel to go round the sides then working out were the chip was under it and marking it off about 1mm farther to the edges and then dremeling that, then using sand paper to get the metal above the core gone, idk if it was because they were dead or what but the metal plate seemed to be fused to the actual core, no idea if there made that way or what.

Ive got a working athlon 64 here somewere i may try find a guide on how to do it and give it a try and see what sort of temp difference there is.

EDIT: from a quick google it apears athlon 64's are easy to do, just use a razor blade to cut around the edges to clear it from the pcb and it then flick it off and there it is, i wouldnt like to say how differnt it would be for newer stuff like 775's ect as they apear to be alot differently attatched than amd chips in general

 

[FragTek]

A64's were a cinch to remove the IHS. Razor blade around the edges and then just a light pry and it will pop right off. I have been told that some Intel chips actually have the core "soldered" to the IHS or somehow more permanently attached.

 

[|3ourne]

yup your right frag , intels are soldered, the newer amds are as well. To the OP , gj on the lapping , the only thing i would change would be starting from a rougher grit like 400 , then you can skip 600 and go to 800 , 1200 and 1500. Remember when you do get to 1200/1500 , wet sand it , add a couple of drops of water, it reduces the scratches you get and also I'd use less thermal paste, but otherwise your on the perfect track ! Gj on the temp reduction

 

[siravarice]

Thanks for the comments guys. I will hopefully be getting it smoother at the end of august when I've got some time off work. Will post pics when I'm done. Also, just a side note of informations really:

If you have two pieces of similar metal, with a perfectly flat finish (or as near perfect as humanly possible) and you place them together within a vacuum, they will slowly bond at a molecular level and become one piece of metal.

Always wondered if a heatsink that was apart of the CPU casing would transfer away more heat?

 

[Elemental_Dragon]

Shiney doesn't mean it's flat. Best way is to take a blade and lay it over the top so you can see imperfections.

~Bex