Since no better info has come conserning the length it will be at the first tunnel that 1260mm long. Inner corners are done and also the reinforcement glasfiber layers to hold the corners and keep the water out of the seams.
DIY Water tunnel inner corners.jpg - Windows Live
Tomorrow target is to get outer corners and ready glasfiber layer to whole inside so I can add water. Still wondering will I buy boat electric motor or build similar wheel like here any ideas which would be better? that wheel is no problem but how to be able to control rotating speed is a problem and also at what speed :/.
Costs so far:
Glues 25€
bolts 20€
wood 15€
glasfibers stuff 15€
time=priceless
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