Heatsink lapping tip

[PorPorMe]

I'm adding larger HSF to the chipset on the EVGA 780i and in doing so came up with an idea ( I'm sure it's not original ) that will aid in lapping heatsinks-especially aluminum base ones. The picure shows different states of anodized aluminum and that is what gave me the idea to put a very light coat of paint on it for the initial sanding. As you can see, the anodizing makes it simple to tell if you have it flat, and these certainly were not.
I would suggest making the paint very thin-even see through, or it will clog your sand paper.

[Daniel ~]

A useful instruction!

[MUff1N]

Originally Posted by PorPorMe

I'm adding larger HSF to the chipset on the EVGA 780i and in doing so came up with an idea ( I'm sure it's not original ) that will aid in lapping heatsinks-especially aluminum base ones. The picure shows different states of anodized aluminum and that is what gave me the idea to put a very light coat of paint on it for the initial sanding. As you can see, the anodizing makes it simple to tell if you have it flat, and these certainly were not.
I would suggest making the paint very thin-even see through, or it will clog your sand paper.

There's just one small detail that's not good you are overlooking going about it this way with paint.

As you know there are "Microscopic" valleys, (that can't be seen with the naked eye) nicks & scratches on the surface of a metal heatsink.
When you put paint into these imperfections it's going to be impossible to get them out without taking the whole metal surface down to where you got nothing but metal again.
What looks good to the eye in fact will still have paint filling in the imperfections which will then lead to higher temps because the TIM won't be able to fill these in which is what it's designed to do.

So now you got a LOT of sanding to do to get it back down to nothing but metal again Mike.

So this really is a bad idea & not a good one!
Sorry to be a kill joy here, just thought I should point this out before you do this again.

Anyways, if you got higher temps then you had before now you know why.

[PorPorMe]

Originally Posted by MUff1N

There's just one small detail that's not good you are overlooking going about it this way with paint.

As you know there are "Microscopic" valleys, (that can't be seen with the naked eye) nicks & scratches on the surface of a metal heatsink.
When you put paint into these imperfections it's going to be impossible to get them out without taking the whole metal surface down to where you got nothing but metal again.
What looks good to the eye in fact will still have paint filling in the imperfections which will then lead to higher temps because the TIM won't be able to fill these in which is what it's designed to do.

So now you got a LOT of sanding to do to get it back down to nothing but metal again Mike.

So this really is a bad idea & not a good one!
Sorry to be a kill joy here, just thought I should point this out before you do this again.

Anyways, if you got higher temps then you had before now you know why.

Sorry, Muffin, but you missed the part about first sanding and you didn't look at the photo.
this is the heavy sanding in the fist place and as the photo shows, there is a lot that needs to be done.
I'll admit I'm not very good at communicating to all-sometimes even to one!
but this works. This is the 120 grit sanding I'm talking about, not the final sanding
This is just to get the over all surface flat. this way, there undoubtedly others, you know when your sink is flat and it's time to start changing the paper.
Everyone is free to try this or not but it does work.