I drilled a 7/8" hole approximately and also had slow leaks from the fermentap kit. I replaced the silicone gasket with two 314 silicone o-rings 70A durometer, 3/4" ID, 1-1/8" OD, 3/16" width (on amazon) on the inside as well as against the bulkhead on the outside of the pot. I tested with a...
I know this is an old thread but I came across it after I ran into the same problem. At first it leaked about a drip a second for me (manageable but I imagine it could be worse for others). I drilled a 7/8"-1" hole and installed the silicone gasket on the inside of the pot with the washer and...