Lapping Questions

[paco83]

I just recently bought a lapping kit from elitecool.com, wanting to lap both my northbridge water block and my cpu waterblock. I started with the northbridge waterblock, following the directions exactly. That came out ok. But When i went to lap my cpu waterblock, it wasn't working. It seems that the northbridge waterblock woredown the sandpaper so much that it is now smooth. I knew that these sandpapers wear down pretty quick, but i expected to get more then 1 lapping out of them. Did i do something wrong? or does this happen with all lapping sandpaper?

Also a day or 2 after lapping the northbridge waterblocki noticed black marks on the bottom. IT seems that my fingerprints left some sort of marks on the block. IS there a way to remove these w/o relapping it? will it affect thermal transfer much?

 

[soja]

Usually I cut up a sheet and use about 3 or more squares per grit. Once a square is used to lap with it's pretty much useless. The finer grits wear away quite fast. I think some sort of tarnish remover will get rid of the oils and smudges but if they aren't near the contact points then I wouldn't worry about it if you can't quickly relap it with the last grit you used.

 

[paco83]

About how small do you cut each piece? And i'll have to try tarnish remover later tonight. Thanx for ur help.

 

[coolroyboy2]

If you have wet/dry sand paper , the water will suspend the particles sanded off and allow you to clean off the water and be left with a usable piece of sandpaper. This will extend the life of your paper. You could also hold the paper up and give it a couple of snaps , like you do to your yonger brother when they are looking over your shoulder, while sanding so as not to allow the particles to get embeded in the paper. Also in auto body area of most auto parts stores or even walmart they sell the right grit sandpaper for lapping.

 

[soja]

Originally posted by: paco83
About how small do you cut each piece? And i'll have to try tarnish remover later tonight. Thanx for ur help.

It depends on what I'm lapping, usually I cut them big enough so I can do figure 8s without running off the sides.

 

[Blooz1]

I'm with soja on this one. I usually cut strips about 4"x6" so I can do figure-8's and rotate the sink 1/4 turn every 10-20 "laps" around the paper. (no "pun" intended!) This just about eliminates directional scratches.

 

[mattg3]

You can get the sandpaper from local automotive paint supply places. I don't think you need to buy a lapping kit per se. If you run out of a particular grit, just pick up some more locally.

Matt