What kind of sandpaper do you use to lap your heatsink?

[Sick0fthelies]

Ive got some philips metal sandpaper that doesnt get it quite as smooth as it seems, i was wondering what grit it best, as i have not been able to get to a home depot to check out the different types, i found this in my garage.

[Stang_Man]

i start at around 160 then to 320, and then to ultra-fine 600.

i'll do my cpu heatsink at 1000 (amd cpu needs it more than an intel heatspreader)... but i just usually stop at ultra-fine 600.

[Susquehannock]

All my sandpaper is 3M. :p

What grit to start depends on how bad the surface is.
A couple of the SK-7 that I've done for friends were so
bad that 100 grit paper was required to get the semi-circular
machine marks out. But others would clean up with
400 grit paper.

In general, I would NOT worry about using anything above
800 grit. On several occasions I have lapped the surface with WET 2,000 grit until the surface was an absolute perfect mirror.
This had no advantage over the 800 grit finish as far
as temperatures.
The thing to worry about most is having the surface perfectly FLAT.

:banana3:

[b|gf|sh]

Stupid question, how are you actually sanding these blocks, with an actual electric sander or just using a sanding block?

Thnx

[Tweaked!]

I have found that I saw no improvment worth all the extra time and effort above 400 grit. Anything more than that is basically for looks and pride, as long as you get it completely and utterly flat, that's all that really matters. 400 grit will render a damn good surface and you can almost comb your hair to.

[Susquehannock]

Originally posted by b|gf|sh
Stupid question, how are you actually sanding these blocks, with an actual electric sander or just using a sanding block?

Thnx


Place the paper on a FLAT surface like a piece of window glass or
mirror and draw the heatsink back and forth.
Rotate the heatsink often to make sure you don't take it
all off one side.
And always use "Wet or Dry" sandpaper for only wet sanding
will give a perfectly even, smooth finish.

Oh ....... let's make sure we are all on the same page
about sandpaper wear. A worn piece of 400 grit is
NOT the same as a fresh piece of 400 grit.
When I say "800 grit finish" I mean to say the finish created
by a fresh piece of 800 grit. Afterall, we can't all have
paper worn the same amount can we? ;)

If you can almost see yourself in the surface after using 400 grit,
I'd say it's almost certainly worn out.

[b|gf|sh]

Thnx dude, gonna give that a show tomorrow then :)

[charlie]

320/400/600/1500
:D

C

[shray]

wanna be leeto like me ?
use the uber 10000 GRIT!

I bought this
http://www.elitecool.com/product_info.php?cPath=22&products_id=91

My slk800 aint a heatsink
Its a mirror.

[q149]

50/150/220/320/400/600
What i start with depends on how bad the surface is to begin with

[Major]

From what I've read, anything over 600grit is for looks and doesn't offer anything in the way of better temps. I've never used anything higher than 600 (wet). IMO though it wouldn't hurt to go as fine as you want.

[Stang_Man]

Originally posted by shray
wanna be leeto like me ?
use the uber 10000 GRIT!

I bought this
http://www.elitecool.com/product_info.php?cPath=22&products_id=91

My slk800 aint a heatsink
Its a mirror.

that's just a waste of time...:rolleyes:

at least you can be a purdyboy geek :p

[YoupY]

400 / 600 / 1000 / 1500 / 2000

I do 1500 and 2000 wet and the rest dry.

After sanding I get my tube with toothpaste, to polish it a little further an I am using copper polish for creating a mirror :)

[Susquehannock]

Originally posted by YoupY
400 / 600 / 1000 / 1500 / 2000

I do 1500 and 2000 wet and the rest dry.

After sanding I get my tube with toothpaste, to polish it a little further an I am using copper polish for creating a mirror :)



:cool: ... using Toothpaste is an old trick for polishing chrome.

Originally posted by Major Slaughter
From what I've read, anything over 600grit is for looks and doesn't offer anything in the way of better temps. I've never used anything higher than 600 (wet). IMO though it wouldn't hurt to go as fine as you want.

Yup! .... I'd have to agree.

Over the last couple months I have installed & reinstalled the
heatsink on my kr7a rig many, many times while doing
my own little Thermal Compound review.
In the interest of consistency (and peace of mind) the surface
was lapped before each application.
A good FLAT and consistent 800 grit was about as good as it got.
In all honesty there was no perceivable advantage from
a perfectly mirrored surface.

:banana3:

[Mr. Thompson]

Using a polishing compound or toothpaste after lapping will leave a residue in the microscopic surface imperfections and compromise the thermal interface. There is no way to remove the residue short of lapping.

Colin Thompson
Arctic Silver, Inc.

[b|gf|sh]

First attempt at sanding: -

http://www.bigfish.fragworld.co.uk/images/2p.jpg

This good enough before I sand something proper?

[Tweaked!]

Mr Thompson, I love you sig :)

Quote:
If the supercooled, overclocking crowd discovers how fast duallies feel, there will be a stampede to build SMP rigs that will make the California gold rush look like a few little old ladies pushing shopping carts at the supermarket.

[gabbax]

600 just 600

[dbwillis]

When I lap my P4's and heatsinks, I use the following grits:>

320-wet
400-wet
600-wet

then go over it with some polish to smooth it...comes out great...I like those two pence pieces..looks real good!

[xgman]

600 to 1000 to 1500

[Sick0fthelies]

I went to Lowes and got some 200 and 600 and it works great, thanks guys.

[gabbax]

over 600 just overkill. if u have a surface that is lika a mirror, where do the small "particles" go? its good to have a little "ruff " surface...(sorry for my bad english:))

[Major]

You guys shouldn't use anything to polish the contact area ! toothpaste and metal polish will leave residue that may impare the thermal interface. If your going to use anything to try and polish the surface, use the thermal paste that you plan on applying. I always rub in some TIM after I lap, not to polish but instead to impregnate the surface with the TIM. But I have found that some TIM's actually do a fair amout of polishing too.

[jmg823]

um for your heatsink u use 800grit then 1600grit THEn u use polishing cream

[b|gf|sh]

Had a go at lapping my slk900 and 2.4 ihs: -

http://www.bigfish.fragworld.co.uk/images/sanded.jpg

Also put PCM+ on it, but not sure whether I put enough on, anyway I'll report back later if it's helped anything :)

[x2sandman]

I use 600 grit wet-dry 3m sand paper that i got from the hardware store for like $2. After like 30 minutes you can see a major difference.

[Sick0fthelies]

yeah, thats what i got, but its not 3m, its some gator grip crap. Mine wass $3 for 5 sheets.

[x2sandman]

Yeah there were 3 sheets in the package i got and i used one sheet the first time i used it and since all the copper got into the "nooks and crannies" :) of the sand-paper it is ever more fine then 600 grit.

I now start out with a fresh sheet and once it is almost to a shine i switch to the sheet that is all built up with copper dust and it bring it to a mirror shine in no time.

[Sick0fthelies]

Do you have 2 accounts sandman?

[rashio]

just wondering but when u sand your p4, i thought the sand on the paper would get in to the little hole in the p4?
will that sand not damage the cpu?
or do u block it up with some thing?

thanks

[rashio]

also 1 more question?
i have as3 on my p4, how do i get rid of the stuff on it?
do i use water or will the stuff be soft so i can just wipe it off?
if i do have to use a liquid, how do i stop it from getting in to the little hole on the heatspreader?

thanks