Lapping success

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Jul 7, 2006
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Well, I got crazy and went to WalMart and got some sandpaper and decided to lap my Heatsink. Well, i started with 3M Automotive sandpaper (made to sand metal like copper, aluminum, and chrome) 400 grit. Did that for 5 minutes. Then got 800 grit and did that for 5 minutes. Then 1500 for 4 minutes, 2000 for 3 minutes, and back of the 2000 as 2500 grit for 3 more minutes. I applied Denatured Alcohol to the sink, and polished it up a bit. It had a perfect mirrored finish. Well, I got it all back together hoping I did everything right, and...........

Old Temps: 38C Idle, 54C load
New Temps: 37C Idle 46C load!!!!!

Yeah baby!!! All is well in my camp again. CPU is OC'd, Memorey is OC'd, GPU is OC'd, and heatsink is lapped with great success. Well, guess its time to upgrade to conroe :cool:
 

dasilva333

Weaksauce
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Feb 2, 2005
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what's denatured alcohol and cheers on ur lapping project ive actually been working on mines too so i was delighted when i sawyour thread, im not having much luck with mines i think the problem stems from the fact that im using old sandpaper with imperfections which keeps messing up the whole surface of it (might buy new one tommorow) but again how is denatured alcohol differnt from like rubbing alcohol?
 

PliotronX

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Denatured is made of ethanol and methanol with other additives to prevent consumption (one sip would make you go blind/die) and has superior cleaning ability to iso, but is more toxic and can eat at plastic or non-metal/glass materials so it's best to keep it off of anything that is not the CPU and heatsink. It does not leave residue that non-pure iso does and is easier to find than high purity iso.
 

rysher

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lapping is overrated. u lap surfaces to make it smoother to eliminate the tiny holes inorder to have a good contact between cpu and HSF. AS5 does it?
 
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Metal to metal is a better heat transfer than through AS5, so it does help if you have a rough surface on your heatsink, CPU, or both.
 

Smoove910

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Just a question...


If you lapped your heatsink and your processor heat spreader such that both had a mirror finish, hypothetically, would you still need a thermal compound between the mating surfaces? I would think since the thermal compond is to inhibit better cohesion between the surfaces that once they are both polished the thermal compound would prohibit the heat transfer rather than help it.

Any thoughts?
 

Jodiuh

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rysher said:
lapping is overrated.
Oh I don't know about that. I had a P4 630 with a concave IHS. With the stock HSF on there my idle temps were ridiculously high. I pulled it off and found the paste in a I I pattern. The chip's IHS only made contact with the sides!! After lapping and checking contact it was perfect. Here's a pic and the results:


 

Erasmus354

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mirror finish != a good lap job. What you are looking for is a flat surface, try showing off your lap job by reflecting a piece of graph paper, that usually lets you see where it isn't perfectly flat.
 

Jodiuh

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Brahmzy:
How did you do your stuff? It seems like a lot of lapping and I'm sure you perfected it after awhile. I'm asking cause it took me a LONG time...
 
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Yup, its holding stable. It used to get to 55C on HL2:E1 and now it gets to 49C,,,,,Idle didnt change much, but its no worse than when I started. I let it run Memtest all night (needed to anyway for memory OC) and its seems to idle right where it did before 37-38C but load tmps are way down.

Sorry I didnt get any pics, but its a mirror finish. I could have done my hair off that sink if I needed to :D

Awesome pics by the way. I like that one of the dual core and the intel sticker
 
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go get some automotive sandpaper (stuff used for sanding metal) and get 400/800/1500/2000 grits. The back of the 2000 can be used for 2500 grit. Start out by taping the sandpaper to either a flat countertop or a payne of picture glass. I used a countertop, as it allows more work space. go 5 min a piece on the 400 and 800 grit papers. then do 4 minutes on the 1500 grit. Then 3 minutes on the 2000 grit. After that, flip the 2000 grit over to the side thats just paper, and use that for 2500 grit. When U sand, do a straight back and forth motion, NO CIRCLES or that will mess shit up. and make sure even pressure is applied to make sure all areas are sanded evenly. After your done with all that, simply go back with Isopropyl or Denatured alcohol to clean the metal. I applied Meguiars automotive metal polish to mine to enhance the mirror effect. Reapply heatsink and whatch the temps fall :D
 

m3ta1head

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solobaricsrock said:
go get some automotive sandpaper (stuff used for sanding metal) and get 400/800/1500/2000 grits. The back of the 2000 can be used for 2500 grit. Start out by taping the sandpaper to either a flat countertop or a payne of picture glass. I used a countertop, as it allows more work space. go 5 min a piece on the 400 and 800 grit papers. then do 4 minutes on the 1500 grit. Then 3 minutes on the 2000 grit. After that, flip the 2000 grit over to the side thats just paper, and use that for 2500 grit. When U sand, do a straight back and forth motion, NO CIRCLES or that will mess shit up. and make sure even pressure is applied to make sure all areas are sanded evenly. After your done with all that, simply go back with Isopropyl or Denatured alcohol to clean the metal. I applied Meguiars automotive metal polish to mine to enhance the mirror effect. Reapply heatsink and whatch the temps fall :D
The way I lapped was that I put the heatsink itself on a table and then lapped it with 600grit for 15 minutes, 800grit for 10 minutes, and then 1500grit for 8 minutes. They don't sell any higher grit here :(

I didn't know how to polish it, but I guess I'll head over to an autozone or something to see if they have metal polish.
 

Borgschulze

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I wouldn't polish it... I would thouroughly clean it, then polish it with Arctic Silver 5, to enhanch the thermal conductivity.
 

Arcygenical

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I wouldn't polish it... I would thouroughly clean it, then polish it with Arctic Silver 5, to enhanch the thermal conductivity.

Agreed. ISO Alcohol 99% (or denatured) or acetone then alcohol.
 

Erasmus354

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Polishing is a bad idea, it will generally take away some of the flatness you worked so hard to achieve. While a mirror finish might look nice, the only thing that is going to see it is your processor, and I doubt that P4 cares how shiny your heatsink is.
 
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yeah, I definately see what your saying, and after all that work, I gotta say I agree......But that shine is awesome :cool:
 
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Wow...I was just about to do the same to my heatsinks and CPU.

My Zalman CPU and GPU heatsinks are lapped from the factory. Waiting on my Zalman NB heatsink and my E6600 CPU. I will also lap the stock D975XBX SB heatsink.

Anyone know if thermal grease should cover the entire plastic top of the South Bridge chip?...or just in the center like a CPU?
 

Jodiuh

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mike_j_johnson said:
My Zalman CPU and GPU heatsinks are lapped from the factory.
The 9500 for LGA775 I recieved could def use a little assistance as I could feel the machining. The VF900 on the other hand still blows my mind. If only Intel and AMD could do the same...
 

gesicht

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little help, what is "TIM"? just seems like all of the sudden people started saying it and i missed the boat.

i checked online acronym's and the best i could find was Transient Intermodulation Distortion. while it sounded cool i dont think this is what you are talking about
 

sparks

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how are you going to hold a ninja on the paper and keep the big sucker from tilting as you work. Sounds simple but it looks really hard.

I just lapped my ninja....best I could find was 2000 grit.
It doesn't look like a mirror but its not flat.

How do you clean it after lapping...I washed the sink with water and then used alcohol to clean all the water off...now the base is clean but it looks like its going to tarnish.



sparks
 

Diablo2K

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Just remember, the smoother your surfaces the less HS Compound you need, the compound is made to fill the gaps in the rough surface to aid in better heat transfer, if you had 2 perfectly flat smooth surfaces the compound would not squish out from between the surfaces keeping them from making any contact with each other and actually hurting heat transfer, just remember, metal to metal contact is best, but not really possible in the real word due to the fact that nothing is perfect. The compound works best when it fills the gaps, not by creating a barrier between the sufaces!
 

Erasmus354

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Diablo2K said:
Just remember, the smoother your surfaces the less HS Compound you need, the compound is made to fill the gaps in the rough surface to aid in better heat transfer, if you had 2 perfectly flat smooth surfaces the compound would not squish out from between the surfaces keeping them from making any contact with each other and actually hurting heat transfer, just remember, metal to metal contact is best, but not really possible in the real word due to the fact that nothing is perfect. The compound works best when it fills the gaps, not by creating a barrier between the sufaces!
Well if you had two perfectly flat surfaces then you wouldn't apply thermal compound the same way. You would then just have to rub it into each surface to fill the gaps and put the two together. However no matter how hard you try you wont get it perfectly flat, but the less convex or concave you make the surfaces the better contact they make. To get what you are describing you have to use a lot more compound then you should. If you are applying it correctly with a little dab in the middle the compound will spread out evenly and you will get good thermal transfer.
 

454Casull

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If you polish both the HS base and the IHS with 2000grit, run it dry first, and then with thermal compound. My hypothesis is that the temps will be similar, if not better without the compound.

This does, of course, assume perfect flatness.
 
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I just lapped my processor heatsink and will be doing my new NB heatsink tomorrow probably unless i get a different one.

However, i had a question related to lapping the proc sheild, are there any tricks to doing this, it must be very fragile and i would not want to do wet sanding like i did for my heatsinks on the processor....

also, is it possible to do the NB? I cant see how you would since you cant take it out of the mobo...
 

shoman24v

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After reading your post I decided to go buy some 400, 800, 1000, 1500, and 2000 grit sand paper.

Didn't do jack shit.
 
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what do you mean??? did u clean the HS between grits??? you should see good diffrence between 800 and 1500 in the reflective surface. On both HS's i lapped, this is where it started coming together. You arent sanding aginst the grain, or in circles are you???
 

shoman24v

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I didn't do it in a circular motion. I taped the sandpaper to a flat surface and sanded it left to right holding it at it's base. By the time I finished I could see my reflection in the Big Typhoon.

Still primes 53c with my case closed. The temps are the same before and after lapping.

And no dust in case/heatsinks.
 

Smoove910

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There's always the chance your IHS (Integrated Heat Spreader) is not making good contact with the core. In this case (for extreme) you could always remove the IHS using a razor blade and try mounting your heatsink to the bare core. Sorta like the Athlon XP's....

All depends on how dedicated you are on getting your temps down.
 

ChingChang

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Erasmus354 said:
Well if you had two perfectly flat surfaces then you wouldn't apply thermal compound the same way. You would then just have to rub it into each surface to fill the gaps and put the two together. However no matter how hard you try you wont get it perfectly flat, but the less convex or concave you make the surfaces the better contact they make. To get what you are describing you have to use a lot more compound then you should. If you are applying it correctly with a little dab in the middle the compound will spread out evenly and you will get good thermal transfer.
Well if both surfaces were perfectly flat, then you wouldn't need anything to fill the gaps (there wouldn't be any!)

Of course we all know that's not realisticly possible though.
 
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