There are a number of posts here about optimal thermal compound application patterns, with the general consensus being the dot method. I saw a comparison with thermal measurements that confirmed this, but I can't seem to find that article again.
A couple of the posts addressed direct-contact heat pipes, and the general consensus there was the two stripe method going down the length of the heat pipes.
Does anyone know if anyone has done measured comparisons of these methods?
And as a side question, does anyone know of any measured comparisons done on a stock and a lapped direct-contact unit?
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Optimal is direct metal contact with thermal interface only filling in air gaps. Lines parallel to the heat pipes should be good for filling in any unevenness between the block and the pipes, but otherwise you want as little interface material as possible. If you're not good at a minimalistic spreading, a dot or line method helps avoid access material for most of the surface, but is still far from ideal.