Lapping discovery

[PorPorMe]

The few articles I've read about lapping a heat sink, The writer was clear to point out how many hours he had spent putting a shine on his heat sink. I can remember one that provided pictures of his kitchen table covered in news print with a small piece of slate for a surface-well you get the idea-he spent 10 hours lapping his heat sink.
Kind of turns a guy off to the idea of doing it himself if thats what it takes.

What a bunch of horse pucky!

I picked up a bottle of course abrasive metal polish at the auto parts store on a whim. I poured a little on a coffee filter and started to rub away on the Freezer 7 Pro. In 10mins I could see the TV 10 feet away if i held it at the right angle to the light, and I mean I could see the show!-otherwise you saw the rubbing marks.
I'll pick up a bottle of medium grit and a bottle of fine grit the next time I'm in the area. I'd wager that in less than 20min total, just holding it in my hands, rubbing with a coffee filter, I'll have the shiniest copper mirror you could want.
Why do some have a need to make something complicated when it just doesn't have to be?
I've seen it so many times it always bewilders me.

In the immortal words of Larry the Cable Guy, " Get 'er done!"

[ccperf721p]

The time spent lapping a heatsink is to ensure flatness giving the heatsink the most surface contact on the CPU.. The mirror finish is a result of the process, not the process itself.

[PorPorMe]

Originally Posted by ccperf721p

The time spent lapping a heatsink is to ensure flatness giving the heatsink the most surface contact on the CPU.. The mirror finish is a result of the process, not the process itself.

OOPPs, Never mind!

Edit:
Sure does look pretty, though.

[robbie]

You are going for "flatness" not shinyness. (sp?)
I have a post on here somewhere about my current HSF. It was GOD awful out of the box. After some rubbing it's a lot better and flatter.

[PorPorMe]

Someone want to tell me, or link. the right way to do it?
Need to clean up after my self!
One Thing i noticed that would be a problem. The base of the sink can't touch a flat surface as the mounting legs are approx.1/4 in longer leaveing the base up off any surface. What would I use to fix that?

[MUff1N]

Originally Posted by PorPorMe

One Thing i noticed that would be a problem. The base of the sink can't touch a flat surface as the mounting legs are approx.1/4 in longer leaving the base up off any surface. What would I use to fix that?

Sorry, but I can't picture this in my mind what you are trying to describe here. Pictures would be nice & would help a lot.

[PorPorMe]

Originally Posted by MUff1N

Sorry, but I can't picture this in my mind what you are trying to describe here. Pictures would be nice & would help a lot.

I'm not very good at explaining things sometimes. I've got some pics here. Now that I knew the criteria, it wasn't to hard to figute out a solution.
I's hard to see in the first pic but the mounting legs hold the sinkup approx a 1/4in.
i found this alum sinh in my box of stuff and it has a stainless plate screwed on.
The last pic shows how the freezer 7 sits on it with positive results. i wrap the aluminium sink in adouble layer of coffee filter and aply the metal polish. Works great as far as it goes but i need to get a finner grit polish.
Here are a few pics.

[bk2life]

let me add my opinion or 2cents into this as i think what one is saying, and another is trying to say.

i do paint on stuff, cars, cases, guitars, whatever.

what does this have to do with lapping? (goofy name by the way)

if i paint a car black, the surface the paint goes on, lets say the hood, has to be very flat, to have that nice mirror or wet look once its all finished.

we do body work, bondo, primer, sand the area with 180, 220, primer again, sand again with 220, if there is no other block sanding to do we then primer it again and wet sand with 400, then 800 grit papers.

what am i saying? well i could simply sand the hood and paint it, (such as you lapping with polish) and it would turn out black and shiny, but not flat. there would be waves and imperfections in the black paint. think of a dodge truck paint job compared to a ferrari paint job.

now bakc to your heat sink/cpu. you can simply polish the metal for a mirror finish. but your not sanding the actual piece flat. that is where the time comes from. when you sand with 400, 800, 1000, 1500, 2000, then polish, you will see a difference. the metal will be flat, measurable with a micrometer flat. and the imperfections will be sanded out.

i found a perfect example of a non sanded heat sink, then i photoshopped the last one (red line is TIM) to give an example of sanded flat or "lapped" parts. see pics

[PorPorMe]

Thanks for the pics, bk2, but I had gotten that concept real quick. I was reading my posts an maybe the fact that I'm using metal polish would indicate I was still after shine. No, I'm using the polish as a fine abrasive against the piece of stainless.
I only have myself as a judge but I think I got it right. Placing a blade from a box cutter corner to corner, shut the light off, and shine a flashlight on it. There wasn't any light between the blade and the sink.
[It was nice and shinny too!]

[Gizmo]

In theory, if you get two surfaces perfectly flat, you wouldn't even need a TIM (in fact, it would actually INTERFERE). The reason is simple: the purpose of the TIM is to fill the voids between the mating surfaces. Two perfectly flat and congruent surfaces won't have any voids at the mating interfaces, and thus there would be no need for TIM.

Unfortunately, I don't know anyone who's achieved that in practice (since I suspect doing so would require some precision machining).

[PorPorMe]

You gave me an Idea, Gizmo. I have the Ximatek HDT-S1283 coming in this week.I'm going to see about precision machining and cost. Just for grins. and I'll be eble to see about soldering the finns on the Freezer 7. Busy week

[PorPorMe]

I've been going through some of these threads because I remember a very short bit about the Ximatek HDT-S1283 and a problem that it is PROBABLY going to have and fairly soon.
Given the the type of sink involved, moister from the TIM, and the warmth being created, the copper is going to corrode fairly quickly with out a different kind of TIM (non-silicon is something that hits my head but could be way off base.)
Any one know about this before I go hunting?

[Gizmo]

I can't imagine why it should corrode, unless you are exposing it to a highly corrosive atmosphere like sea spray on a yacht or something. There's no TIM I know of that uses water as a carrier; they are all based on either mineral oil or silicone grease of some kind, neither of which will cause corrosion of the copper. In fact, the TIM will help PREVENT corrosion of the copper, and it provides an air seal (that is, after all, what it is designed to do).

[PorPorMe]

Your word is good enough for me! I just remember a short statement, without any context and thought i'd better do some checking with better heads than mine!
Thanks-another one off the worry list!