Hello first time threader here at Robobrew. Does anyone know what size hole is used for the ball valve?
It’s a standard 1/2" fitting. The hole itself is around 21mm diameter.
I bought a sightglass from Brew international.com
It fits in the ball valve hole without a problem and no leaks. So, no drilling nessesary. Also the sightglass fitting will accept the Robobrew ball valve.
Nice find for a sight glass. How did you attach it at the top? It looks alot like the Fermentap sight gauge i have seen online and was thinking about getting. But your source has a much better price that others i have seen.