Cooling Lapping Copper...

I'm guessing it will take a good few hours per block of copper...

Just started lapping my 4 blocks now, but the grit of paper Igot only goes up to I think 800, as was a cheap-o sandpaper set my mother got while she was in town, as I was saying I was gona get some, so she treated me (wow!)

Started on 80-grit now on the big lumps... Only 1 sheet though

 

takes me about 2 hours to lap a heatsink.... going from around 200 grit up to 1500 grit

 

Well the 'cheapness' of the sandpaper really showed up... Plus it only went to 150grit not 800 So ended up going the pub for a few rounds & then came back.

Started off sanding one of the thicker top-plate blocks, and it was all going well, but then the sandpaper ripped & it just went down-hill from there

Mind, the blocks do look a 'bit' better, but not good enough, so asked a friend of mine who works in a DIY store to get me some of the best wet-dry sandpaper they got & he says they go from 120grit to 1600grit, so that should do me fine! Will have it tomorrow...

 

Only takes me around 10mins to lap a sink. (tho it depends how bad it is to start with)

You relly need to get hold of some 800grit wetndry paper. You dont need any higher than 800 but i would also get some 320 to start of with. You also need to make sure your lapping on a very flat surface (a mirror is acceptable) if your not its pointless

 

agreess.. not much point going over 800-1200.... we got some 3000 here at work

 

Does it feel like silk?

 

Being done on a pane of glass

 

lets just say, my skin is MUCH rougher. so is my polished wooden desk.

 

Has anyone ever 'sanded' there finger down so its red raw & bleeding slightly???

Well mine is, and I aint finished yet!!

 

It took me about 1.5hrs per sink but I lapped my new zalman 7000a and zm80a HP sinks with 320-2000grit wet 'n' dry. My tips:

1. Before you start sand the corners and edges to give a slight bevel - prevents the block ripping the paper
2. Use LOTS of water!
3. Wash the paper and block 1-2 times per grade per block
4. Move the block backwards and forwards along a stip of wet 'n' dry turning it every 10-15 times so that you sand in all directions evenly. Keep sanding until the change in lustre of the heatsink is even across the surface then move to the next grade of paper
5. Do it near a sink as fine copper/aluminium particles get everywhere
going past 1500 doesn't make much of a difference (though you'll see a big difference by the time you get to 1200)

I got a noticable drop in temps: 3 degrees on my Ti4200 and 4 degrees on my CPU (thought this could just be the clean up and reapplication of arctic silver)

Good luck

 

I've only got up to 500 grit paper now, but just doing 260-grit & noticing a hell of a difference! Have enough paper to use 2 sheets per block (1 sheet per-side of each block), so should hopefully help get a good finish!

I'm also using some washing up liquid, just a small dab smeared on each side, its effectivly causing the block to be 'sucked' down to the paper, so making alot more force but without applying pressure to the blocks! Also I noticed its getting better results quicker doing this rather than just using water!

Gona just finish this one piece off now then call it quits for the night!

 

I have emery cloth which is fabric with some gritty stuff on one side - it's around 1500 grit if you were to classify it - it's really used for polishing. But anyways, I do 220 grit, 400 grit wet/dry, and then the emery cloth, and then the back of the emery cloth - just fabric. It gets it shiny. I use alcohol as my liquid, as it suspends the particles a lot better.