What is your favorite lapping surface??

[mgpaulus]

I was in our local Bed, Bath & Beyond, and I saw this cutting board that looks like it's a 3/8" - 1/2" chunk of solid tempered glass. It looks massive enough to be steady while lapping. But I'm not sure if it's flat enough.
I also had thought about a marble slab cutting board.

Just wondering what others are using, and where you are acquiring them??

 

[Crucial]

I have a 18in x 18in mirror. It's about a quarter inch thick and it super flat. Works great.

I don't know where it came from. I got it from my old man.

 

[Dink]

I'm using a glass cutting board as well. I dunno where it came from though, my wife got it from somewhere. HEHE

 

[DAPUNISHER]

<< I have a 18in x 18in mirror. It's about a quarter inch thick and it super flat. Works great.

I don't know where it came from. I got it from my old man. >>

Does your dad have the sniffles alot?

 

[playgroundtwister]

<< Does your dad have the sniffles alot? >>

 

[Dre]

<<

<< I have a 18in x 18in mirror. It's about a quarter inch thick and it super flat. Works great.

I don't know where it came from. I got it from my old man. >>

Does your dad have the sniffles alot? >>




:Q

 

[Jeff7]

Uh, I use my computer desk. Seems to work fine too. My generic heatsink/fan combo keeps my T-bird around 42F under load. It will reflect anything that's within an inch or two.
Top of heatsink

Lapped bottom

 

[ShiFtY1000]

personally i use a kitchen table, mine has a totally smooth surface which is good. Then i use Autosol metal polish, which is a fine rubbing compound used to polish aluminium. This gets a true mirror-like finish, which is the best for heat conduction.

 

[Crucial]

[/i] >>

Does your dad have the sniffles alot? [/i] >>



Heh! No he bought it as a mousing surface after he saw the intellimouse explorer display. Much to his amazement it didn't work. He had no use for it after that.

 

[Deadlifter]

I just used a plate glass storm window to lap an SK6. I duct taped the endges of my emory papers to the glass and progressively upped the grits until I got a mirror finish (and boy was this a lot of work at first since that thing was concave to start with!).

Anybody have a better idea of how to keep the paper down flat? It still seemed like it wanted to shift/wrinkle on me if I was careful in my circular motions.

 

[Cuke]

I'll be using the wife's Corning hotplate/cutting board (flipped over - smooth side up).

I like Deadilifter's idea of duct-taping the paper down, too bad it still shifts. Maybe
gluing around the edges (but not in the middle sanding area - will make it un-flat)
will keep things in place.

I've got 220 330 and 400 grit paper from Home Depot.

Do I sand wet with all 3, or just the 400?

Has anyone lapped the heatspreader cover on a P4 Northwood?
What about the little hole?

Thanks for the input !

 

[Wuzup101]

You are going to need higher grits than 400...that's what I would suggest starting with. You may want to go up 2 2k grit...or consider using some kind of rubbing compound instead. I would go 400 wet just to get it flat, then 600 or 800, 1000, 1200, 1500, then either the polish comp or 2k wet...(also all those other grits would be wet as well of course). You can get packs of assorted papers pretty cheep at any auto body store.

 

[Crucial]

Wow all those grits seem like overkill. I started with 240 went to 400 and finished up at 600. FWIW I don't believe a mirrored finish is necessary. And I would never use a polishing compound. The compound will get stuck in the microscopic pits and valleys. It won't all come out. You want those to be filled with thermal compound.

What you want is a very flat and smooth finish.

 

[dkozloski]

I use a Starrett Master Pink Granite toolmaker's surface plate that that is flat, corner to corner, to 0.00005in. tracable to the National bureau of Standards. It measures 12"x8"x2" and weighs 20lbs. in a fitted felt lined oak case.

 

[Richardito]

None... I use my hands, some paint buffing compound and some auto wheel polish paste. With just this I was able to reduce my temps by 2ºC on my 2 systems. And it only took me about 10 minutes on each HS!

 

[HardwareAddicted]

Ok....WHOA !!!

This is a good question and has a very cheap and effective answer.

Go to your local hardware store, (remember, I'm addicted)
and get a 12"x12" peice of marble tile that has the glass finish. (Some have the marble finish, DO NOT get that kind)

It's about .5" thick and very very smooth....

At about $3, this is a no brainer....you can duct tape your wet/dry to this and get crazy...

I do this in a basin by my washer and rinse often to keep the paper from loading up.

I hope this gets you on your way....

Happy Lapping

 

[Degenerate]

I know this is a stupid question.. but what is a lapping surface??!

 

[John]

<< I know this is a stupid question.. but what is a lapping surface??! >>



A super flat surface to lap something on.

 

[Degenerate]

what about the meaning of 'lapping'?

 

[Jerboy]

Am I the only one to admit to using Soft-Scrub ?

 

[mgpaulus]

Degenerate: Lapping is the art of milling and/or sanding your <component name here; e.g. Heatsink, CPU, memory, bearing, etc> until it has a very flat, smooth surface, within certain tolerances. In our useage, we want to get the smoothest surface possible on our heatsinks, because the best heat transfer occurs between a metal to metal surface. In a perfect world, the Heatsink would be attached directly to the CPU die without any heatsink compound, because the two surfaces would mate perfectly and would require no compound to fill in the little crevices. (Also, in a perfect world, when those two surfaces would mate, they would literally lock together). The smoother the surfaces, the fewer imperfections present, the more metal on metal you can see, and the smaller quantities of HS compound required.

Hope this answers somewhat intelligently.

And, Jerboy, I had wondered about SoftScrub for the final polishing. All the polishing compounds I looked at @ pepboys looked like they left a "protectant" film, which I would think would defeat the purpose of the whole lapping process in the first place.

Haven't had time to do the lapping yet, but I have a project that I will practice with first, before I try it on my Taisol GCK760092. Got a lapping kit from crazypc with 400, 600, 800, 1000, 1200, 1500. And the HS I will practice on looks pretty concave against the CPU, so I think I'll get a good work out

 

[Jwyatt]

lap2 Pronunciation Key (lp)
v. lapped, lap·ping, laps
v. tr.

To place or lay (something) so as to overlap another: lapped the roof tiles so that water would run off.
To lie partly over or on: each shingle lapping the next; shadows that lapped the wall.
To fold (something) over onto itself: a cloth edge that had been lapped and sewn to make a hem.
To wrap or wind around (something); encircle.
To envelop in something; swathe: models who were lapped in expensive furs.
To join (pieces, as of wood) by means of a scarf or lap joint.
Sports. To get ahead of (an opponent) in a race by one or more complete circuits of the course, as in running, or by two or more lengths of pool in swimming.
To convert (cotton or other fibers) into a sheet or layer.

To polish (a surface) until smooth.
To hone (two mating parts) against each other until closely fitted.


Ideally to hone 2 parts together would be great for a slug and the HS. If you have both parts lapped/polished you use some lapping compound usually found in some automotive stores or use some polish as people have suggested here. Then lap the cpu slug and the HS together with the compound. This will give the best fit IMO. This works best when doing something like valves in a car where the valve seat is rounded to match the valve then the lapping is done to insure there is a good seal, but when you lap that you rotate the valve inside of the valve seat. I wonder if theres a way to do something similar with CPU/HSF?
Just a thought.




v. intr.
To lie partly on or over something; overlap.
To form a lap or fold.
To wind around or enfold something.

n.

A part that overlaps.
The amount by which one part overlaps another.

One complete round or circuit, especially of a racetrack.
One complete length of a straight course, as of a swimming pool.
A segment or stage, as of a trip.

A length, as of rope, required to make one complete turn around something.
The act of lapping or encircling.
A continuous band or layer of cotton, flax, or other fiber.
A wheel, disk, or slab of leather or metal, either stationary or rotating, used for polishing and smoothing.

Pulled from dictionary.com