I put on the Volcano 7 about 10 days ago with Artic Silver III. I was hoping that it would drop a little further than 51-52C. Instead it gradually rose to 54-55C. I put the ducting mod on a couple of days ago (what a PIA) and it brought the temps back down to 52C but it seems like I may have done something wrong mounting the heatsink if the temps gradually went up during the "burn in" period rather than down as they are supposed to with ASIII.

What do you think? Not enough thermal paste? Too much? In lapping the heatsink is it possible I got it "shiny" but actually less flat? What are some techniques for keeping heatsink perpendiculat to sandpaper so the suface stays flat?

The main technique that I have heard about is putting the sandpaper on a pane of glass and moving the heatsink against it. I does seem likely that it is off a bit if the temps went up...

Lapping: here's how I do it. Not saying it's the only way or the best, but it has always worked for me:

- Put a piece of plate glass flat on your table or bench. I use a glass from a picture frame;
- Use duct tape to firmly secure the waterpaper to the glass. Duct tape is water-resistent;
- Use a little more duct tape to secure the glass to the bench/table. Just to keep it from sliding around;
- Wet the waterpaper. Have a small container or glass of water on hand.
- Hold the heatsink with the thumb and forefinger or both hands and slide it along the paper away from you. At first use almost no pressure, just let the heatsink float along until the paper is evening wetted and starts to 'work';
- After the paper is evenly wetted you can use a bit more pressure. Not too much or the edge of the heatsink will dig into the paper and rip it. Then you have to start over :)
- Repeat steady strokes, applying some pressure as you push the heatsink away from you. Don't try to go back and forth, just go one direction then pick it up for the next stroke.
- After a dozen or so strokes, run some water over the base of the heatsink and examine it carefully. If the heatsink is perfectly flat you'll see continuous, fine scratch marks across the entire surface. If there are hills or hollows, the scratch marks will be discontinuous;
- Your object is to produce continuous scratch marks, indicating that the entire surface of the heatsink is in contact with the waterpaper. If it is, then the surface of the heatsink must be flat.
- Continue lapping, and count your strokes. Every ten strokes, rotate the heatsink 180 degrees. Occasionally, slosh a little water across the paper to clear some of the residue;

I usually start with a 320 grit paper and when I've achieved the "continuous scratch marks" stage I switch to a 600 grit paper. Another 20 or 40 strokes then will polish up the surface a bit better. Then I quit. The surface still has extremely fine scratches, but these do not matter. The heatsink compound will easily deal with those.

It is extremely important to have a clean work area. If you get a foreign bit of grit between the heatsink and the paper you can quickly cut some nasty gouges in the heatsink surface. I know this because I did it :)

But before you lap that heatsink again, I'd try remounting it. Clean it up really well first using rubbing alcohol. Apply Arctic Silver according to instructions on their website. You only need to rub it into the heatsink surface, not apply a layer. Apply a very thin layer on the CPU core -- here, err on the side of too little rather than too much. Read the Arctic Silver instructions and follow them exactly.

Thanks for the detailed instructions. I did use a pane of glass but not the technique you described. I did follow the instructions that came with the ASIII. I scraped the edge of a credit card across the surface to spread the small amount over the processor and was just barely able to get the surface covered. It sounds like you are thinking there still may be too much on there?

The ducting mod does seem to be working fairly well, keeping the temp at 51-52C.

No, probably not too much. But if that heatsink is any good the temperature should be lower.

What CPU do you have? I'm assuming an Athlon. I think you should be able to get it down into the 40-45 range.

Just to add to sleddog's nice instructions.

When you change from a coarser grit paper to finer grit, be sure to clean all surfaces. You don't want any 320 particles to be touching the heatsink surface once you change to 600.

Clean the heatsink, the table area and the glass between grit changes.And use some new water.

You may not have seen my other post. Before I changed the heat sink I was running 60-61C and it got up to 64C a couple of times. I think the heatsink made a big difference. Today it's running 50-51C but the conditions are different as it's snowing and damp and cool. Last Sunday it was 75 degrees outside and by Tuesday we had a raging blizzard so the ambient temps are flucuating, even indoors. I ordered a ducting kit which fits on the fan to channel cool air from outside directly to the heatsink. If that keeps me at 50 or below I'll likley leave it as it is. I did archive the lapping instructions for later use.

A graduated progression of grade/grit wetpaper to use...from coarsest to finest...is:
120 grit
220 grit
320 grit
400 grit - wet
600 grit - wet
1500 grit - wet
Use electro-coated waterproof silicon carbide papers.

For a mirror quality finish polish the surface further with #0000 steel wool followed by a good rub down with crokus cloth (crokus cloth is a commercially available cotton cloth treated with a superfine abrasive that will not scratch - used in machine shops).

Another trick I learned from the overclockers is to preheat the Artic Silver conductant paste in hot tap water for several minutes before application...it flows a little better when warm and will more readily fill unwanted voids...

Be sure that your fan is blowing towards the heatsink and cpu (this advice is from Ian Felts, owner of 2Cooltek.com)

How many casefans do you run?(I run five and my cpu is holding at 42 C under load at room temp of 74 F)
Hope this helps....