When you lap do you use wet sandpaper?

[MidnightClocker]

What grits should I use?

And what buffing compound do i need?

 

[Shadow ÒÓ]

MidnightClocker (May 14, 2001 12:49 a.m.):
What grits should I use?

And what buffing compound do i need?

For the basics.......320 is a good starting point. Only need it that 'ruff' as it's easier to take the finish off as well as get it flat. The more steps you use the easier it is each time. Move to 400.......600.........800........1000.....then it's up to you from there. I'd recommend you finish with at least 1500 or 2000 tho. Polishing compound really isn't necessary unless you want to squeeze one or two degrees more. (c that is)

if you really want the mirror finish, you can go to an auto body shop and pick up polishing compound, however I think the smallest amount you can buy is about $20 USD and would probably do sever thousand heat sinks.

Crest has been VERY sucessful for me, so you may wanna consider that. No kidding....I got a mirror finish from the normal crest toothpaste. Some recommend a final sand with Artic Silver as a lube on the final sand, but I believe that's about as much overkill as my polishing this thing to the mirror finish.

[img=[URL]http://albums.photopoint.com/j/View?u=96108&a=12347703&p=47229002&Sequence=0&res=high[/URL]]

 

[Colin]

Shadow ÒÓ (May 14, 2001 12:57 a.m.):
Some recommend a final sand with Artic Silver as a lube on the final sand, but I believe that's about as much overkill as my polishing this thing to the mirror finish.

And lapping and water cooling aren't overkill?

Seriously, the Artic Silver trick works. Instead of leaving residue from your paper and lapped object in the surface imperfections, you get some Artic Silver there in the mix. That's where you want a thermal compound.

 

[MidnightClocker]

Hey thanx for the tips.

You REALLY helped me out.

Just one more thing. Do I use wet sand paper or is it ok to do it dry?

 

[Colin]

Wet, and flush the paper frequently. If you wet the back of the paper, it will stick to a flat piece of glass.

 

[Shadow ÒÓ]

Colin (May 14, 2001 01:16 a.m.):

Shadow ÒÓ (May 14, 2001 12:57 a.m.):
Some recommend a final sand with Arctic Silver as a lube on the final sand, but I believe that's about as much overkill as my polishing this thing to the mirror finish.

And lapping and water cooling aren't overkill?

Seriously, the Arctic Silver trick works. Instead of leaving residue from your paper and lapped object in the surface imperfections, you get some Arctic Silver there in the mix. That's where you want a thermal compound.

Nah....don't think water coolin is overkill........but I'll bet the difference between lapping with 2000 and lapping with crest or AS as a lube is almost insignificant.

Use wet sanding as the water keeps the paper from becoming clogged. you can use one sheet to do several cores or heat sinks.

 

[MidnightClocker]

People lap cores?

Dang, a little to risky for my blood.

 

[Shadow ÒÓ]

very risky.....well.....assuming it's your first time.....

lemme restate what I said above tho.......

the difference between air and water cooling is huge! The difference between finishing with 1500 or even 2000.............or finishing with 1500/2000 and using AS or even crest is almost nothing. That's what I mean by overkill.

 

[Colin]

I got a 2C drop in temps using Artic Silver and a fresh sheet of 2000 grit with the FOP32 I use on my bench. Of course this is with the in socket thermistor, so factor this into my results, but it does correlate with the thermal interface, if you look at it in the proper scale.

Lapping cores? Done that twice with good results. I don't recommend it unless you can afford to waste a CPU. Since I am just about ready to fire up a dual 172 pelt rig, I'll pass on core lapping for a while. With straight H2O or aircooling and I would eventually get around to it though.

 

[Shadow ÒÓ]

ok I'm gonna guess that 2 c is an outstanding result........but I'll try it and post back with the results in a few days. I still don't think this is the average result.......

no matter what.......2c isn't exactly extreme like moving from air to water......but a bit impressive none the less.

 

[batboy]

Any drop in temp, no matter hiow small, is a victory in the fight against heat.

 

[jgaud]

Colin (May 14, 2001 01:18 a.m.):
Wet, and flush the paper frequently. If you wet the back of the paper, it will stick to a flat piece of glass.

will everyone please try a little (couple drops) of dish soap it really keeps the finer papers from clogging so quickly the surfacants in the soap will carry away the particals

 

[LimeyGreg]

I know this thread is old, but did you all read the interesting page about lapping on the front called "Heatsinks Too Flat" by Simon Watkins? Makes for very interesting reading, I think this is where Artic Silver will show it's true capabilities.

Incidentally, I did a search on Goolgle for lapping info and it appears that for soft materials such as Aluminum and Copper etc, garnet is the preferred medium for lapping due to its softness (compared to other materials). We have "garnet" paper at work that I used to lap my Panaflow Orb, but then I used 1500 Wet and Dry to polish it, I think I will try lapping it again and get some AS to see if there is any difference.