Tales of a ‘Shade Tree’ Machinist Revisited – My Homemade Water Block Mark II

Detailed pics to build a spiral waterblock. — Owen Stevens.

After making my first water block via my drill press mill, I longed to try again for a better performing water block. I looked around the web and found that the spiral type flow path seemed to be pretty effective. After my copper cap water block performed lack luster, I needed a new challenge.

I used the same materials as before – some copper bar stock of 1/8″ and 3/8″ thickness. Here is the base with my proposed flow path drawn as interlocking circles.


This time I remembered what I was taught in metal shop about using a center punch to mark the center of each hole to be drilled.


The marks keep the drill bit in the starting point you choose and not sliding around. So next I drilled the holes to a depth that left 1/8″ in the base. Here it is cleaned up.


I bought these end mills after my last attempt at machining – they are designed to make flat bottomed grooves in metal. I left the 5/16″ dremel bit here for comparison, it’s the little one on the left side. The set I bought was $14 from Grizzly Tools and I ended up using the 5/16″ and ¼” drills to make the channel.


Here is the flow path after I machined out the channel, leaving the base about 1/16″ thick:


The flow path sides are pretty rough – that will increase the turbulence and improve heat transfer. To finish the block off, I soldered a 1/8″ flat bar stock as a top and tapped two ¼” pipe thread holes for the brass inlet and outlet fittings. Sorry, I slacked off here and didn’t get a lot of new pics. Here is a shot of it installed in my system:


I used a new connection method that uses the brass stand off bolts that you get for mobo mounting. I attached the stand offs to the four mobo mounting holes around the CPU and then attach the block with 1-1/2″ bolts and 1″ springs.

The idea is that I only partially compress the springs to a fixed compression as I tighten them into the stand offs. This new connection gives me the correct contact pressure (~20 lbs) every time without crushing the core (one of my bad habits).

The flow path is the opposite as before, with the flow entering the end of the spiral and leaving via the center. I got a temperature drop of 2 C with this new block! I attribute this to the fact that counter flow heat exchangers work better than parallel flow heat exchangers. I will test it in the opposite flow path later. I hope you enjoyed my Mark II water block story!

Owen Stevens

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