block lapping/oxydation question

I had to do some rebrazing on my cpu block for the phase change i am building. I had lapped the base of the block to 2000grit, and after some brazing teh copper became oxydized, all discolored. WHat I am wondering is whether this will affect performance, and wheter I should go over it again with some 2000grit. It should still be perfectly flat, I jsut do not know how the oxydation will affect the thermal transfer.

thanks in advance...

all copper does that
all you need to do is get an sos and wash it if you want it shinny
but it does not affect the heat transfer at all

Actually copper oxide will have a higher thermal resistance than copper. And no, your block is probably not perfectly flat anymore. You'll probably need to do some lapping.