Skynetbeta

SLA printing water cooling components is possible .
You need to make sure that your part is fully cured and that your resin is non reactive once cured.
I would suggest a resin rated for food or medical use. 
 
In regards to FDM printing of water cooling components both material and post processing is key.
I have have gotten the best results when printing in nylon carbon fiber. The key is to print with 3 mm thick walls and in an orientation to prevent shearing of the layers. 
After printing infiltrate your parts with a low viscosity epoxy resin and sand to your final dimensions. 
 
Alternatively if neither of the above methods is available to you simply print out of your material of choice then make a silicone mold.
Once you have your mold you can cast out of a clear resin or urethane.
Casting your parts also allows you to add thermal additives making the fabrication of heat-sinks possible.
 
 

SLA printing water cooling components is possible .
You need to make sure that your part is fully cured and that your resin is non reactive once cured.
I would suggest a resin rated for food or medical use. 
 
In regards to FDM printing of water cooling components both material and post processing is key.
I have have gotten the best results when printing in nylon carbon fiber. The key is to print with 3 mm thick walls and in an orientation to prevent shearing of the layers. 
After printing infiltrate your parts with a low viscosity epoxy resin and sand to your final dimensions. 
 
Alternatively if neither of the above methods is available to you simply print out of your material of choice then make a silicone mold.
Once you have your mold you can cast out of a clear resin or urethane.
Casting your parts also allows you to add thermal additives making the fabrication of heat-sinks possible.