Jump to content
Sign in to follow this  

Modding SI-120

Recommended Posts

Decent guide except for using the kitchen countertop. Thermalright isn't known for having any problems with flatness or finish quality.

Share this post

Link to post
Share on other sites

Yeah, I lapped my TDX and XP120 using a similar guide, but used a mirror to place my sandpaper on. With the XP120, temps drop 2-4 degrees, got better results with my TDX block. :nod:

Share this post

Link to post
Share on other sites

Yes somewhat.


I would'nt use any soap though, as it would likely burn into the metal.

Making it black, which would suck...


Dry sanding gets a finer finish, but burns.

If wet sanding, use cold water, and rinse both the paper and heatsink off offen.


Use glass, don't use anything else, this makes a big diffrence, not a little one like others might say, it's important.



When looking at it from time to time, look straight at the heatsink, not at an angle.

Well you can, but look straight at it too.


If going by dry sanding, replace the paper as offen as you can.

If you notice burn marks on the paper or heatsink, move to a diffrent area to sand, or replace the paper.


Wet sanding is quicker, for one is more harsh on the heatsink.

For two, you can move the heatsink faster, or the glass(reccomend a sheet of glash and moving the heatsink though).

The other method is only really for tight spots, a piece of glass in a tight spot srta thing...


Finish with dry if you prefer though, this is what I do, I allways get the better finish with dry sanding.



Don't move the ehatsink to much, as little as possible.

I mean move it back and forth, the bigger the easier it's gonna go down and stuff.

Liek left to right, but not up and down, sort hard to explain that but I hope you get it.

You want very circle like motion, that's what I mean by the up and down.

You may choose to go up and down, then do very little left and right as possible.

You must have a little though, as it'll burn or the paper won't work well if you don't(getting metal stuck on the paper and not sanding certain areas, sometimes leave a deap line in the heatsink).


Don't go nuts and start doing it in a circle, you'll regret it.

I don't know why people reccomend to doit that way..., you can't expect any sort of finsh doing something like that.


Go with the grit of the heatsink, if you understand.

Like sanding wood.

From time to time you may swap this around for a while if you're not planning on a finish yet.



Alot of those giude starts with very harse sandpaper.

This makes things very very hard down the road, making it 10x longer then it should of took to get those deep scratches out you put there.

Use the finest pepr possible, if feal you absolutly have to, use a hrse one.

But sand very soft like.


Soft like sanding gets you a finer finsh, use at the end.

If you are begining and using very harse sandpaper, do it very softly.

You'll defenltly regret that if you apply pressure with low grit sandpaper.


That's about it.


Oh and if you have burn marks that you need out.

You may want to dry sanding wth running water over it.

That way it's getting cooled and washed, so you can get the shine back.

Then if you prefer dry sand(hopefully you want burn it again though).


Most of it's experience.

I just told you what I learned from it.

Share this post

Link to post
Share on other sites

THanks guys, I was thinking about that soap concept as well NEOAethyr. I mean I picked it up and it absorbed my finger oil very fast. This made me suspicious that sanding it down with a harsh viscosity liquid would mess it all up. I just bought a Dremmel Rotary tool with the option to sand and buffer things at will. Dont think I will sand it with the Dremmel but the buffer is bad A$$. Well thanks guys, any other comments will be appreciated.

Share this post

Link to post
Share on other sites

:), good luck on that black_dought.




Copper is a whole diffrent story compared to aluminum.

Aluminum is much harder most of the time to get a good finish out of.

I've worked on both.


I have'nt had copper get dark on me before even using old sandpaper.

Though it does get what you may call foggy, proabbly better to say it loses it's luster or finish.

That's what would happen with soap.

Aluminum get's dark easy sometimes if you're using the same sandpaper over and over.


I've tried oil once, tuf oil because that's all I have fro who knows where and when.

Anyways this stuff only made a mess.

I'm very sure soap woudl do the same, it would get darker and darker.

And I don't see the point in using a bit of it for a couple passes and doing it again and again.



It's best to just wet sand perhaps, then dry sand in the end with a new sheet.

If needed, some low grit at 1st with very light passes.



The grit you ma wanna use, 1000grit does a good job.

1500 grit is alot better, I mean alot, it's like making super light passes with 1000 grit but better.

You can still see the scratches with 1000 grit, however with light passes of 1500, you can barely see them at all, even when looking straight at the heatsink.


2000 grit, I have no clue, I can't find it around here.

1500 grit around here goes around $6 I think, 3 or 4 sheets.



I take a sheet and warp it tight around a sheet of glass.

What I do is, fold slightly around the edges, then I remove it and fold in a bit more so it's a tighter fit.

Then I tape the paper to the sheet of glass on the backside of it.


So princeable with a small piece of glass when in those tight spot, inthose case you have to watch out and not sand the pcb of whatever you're sanding...

Works well for cpu cores, gpu's, etc.


The sheet of glass, I'm thinking like a picture frame.


Tis is for the high grits anyways.


Low grits, do whatever you want, just so you know you don't want it unlevel, you don't need to go to the extreme of using glass there though if you don't want to at that point.



A buffer wheel or something, I'm not sure on how to do that.

I would assume you're want some sort of press like setup, where you could lower the wheel and move it back and forth/side to side maybe I dn.

Probably use nylon on that since that's that they use in industrial buffering stuff.


A regular sandwheel may work out well for the low grits, I'd use the finest sanding wheel you can get though.

I'm thinking it's use may do well on initial sanding, to get rid of the major flaws that low grit sandpaper is used for.

I've never tried this, I don't have any, I do have drills though...

Would be worth an experiment though for sure, may save some time and effort, which is worth alot when lapping.

Share this post

Link to post
Share on other sites

i lapped my si-120 long ago.. i must say it seems like a waste of time. I didn't see any imporvement at all. all it did really was remove the nickle plating which i was worried about.


After the sand paper process, i spent 2 hours watching a movie and rubbing polishing compound on it at the same time (3 large micro fiber rags :P ) to make it spotless and it was.


a few pointers.. its hard to grip the base b/c of the heat pipes make it a bit akward. do NOT grip from the fins. I used soap (w/ a bit of moisturizer and a garden smell), drop a bit on the sand paper everytime u move to a new sheet and when u wash off the metal particles.



good luck. post your results.

Share this post

Link to post
Share on other sites

i don't mean to sound like i am questioning your knowledge, but what are you using to sand if you are getting burn marks? i mean you have to be going like gang busters to heat up the material enough to "burn".

Share this post

Link to post
Share on other sites

Yeah, same here, what burn marks. You gotta be really pressing on the material to get a burn mark, even then the sandpaper would get torn from the sharp edge of the block or HS. I started with a 400 grit and finished with a 2000 grit on my HS and block, moving them with just their weight. Although just for the hell of it I also lapped my P4 DD block that I used for my Prescott. I started with the 800 grit and ended with the 2000 grit and pretty much got the same mirror finish. I did all this back in the summer and believe it or not my TDX block on my Opteron still have that mirror finish to it, although I have reseated and removed it more times than I can remember because it progressed from my Newcastle/Ultra-D, X2/SLI-DR and finally on my Expert with 2 Opterons. Just last week I had it reseated again because I tried the procedure of applying the AS5 on step #7 on the instructions, and believe it or not @1.68 vcore it idles at 32-35 right now I am priming again because it is raining here in Hawaii and we have a flash flood warning, AGAIN, @ 1.68 vcore 310X9 and so far it has been 4 hrs of the custom test and the temp is at 46-49 underload. :D:D:D

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Create New...