Originally Posted by JimE
What size o-ring and what size washers did you use with the 1/2" nipple in your Rubbermaid MLT?
I used the original rubber seal and 3/8" fittings in my MLT, as per my MLT build (see my signature for the link).
For the HLT I used 3/4" washer (IIRC) from McMaster-Carr and an o-ring from my LHBS that was designed to fit a 1/2" nipple (sorry, I don't know the actual size).
FWIW, the 3/8" fittings work better in the mash tun because the seal is so strong and the fittings are so tight. Also, in a mash tun there isn't a great advantage to having 1/2" fittings because you don't need to drain it quickly (even for batch sparging). I do like the 1/2" fittings in my HLT, however, because I do want to move water out of it as quickly as possible, and I am never inside stirring (like I am with the MLT) so there is no risk of knocking the fittings loose. Just my $.02.