This year will be our 2nd year with extended maceration. Last year we did this with our Cab for 1 wk past dryness and we had tremendous success. This year we are going for 2 weeks. What we did in the past was: put two sheets of plastic wrap on the wine surface poke 2 holes (one as an inlet and one outlet) in the fermenter. then we sealed up the primary (except the 2 holes) in one hole we pumped CO2 and after a few minutes, plugged the exit (once we thought sufficient O2 had left) we then pressurized the primary with CO2 just a bit so our seal puffed up a bit. This would be our indicator of a leak if one occured. Every day I would add CO2 and allow some 'air' to escape through the exit at the same time, thus decreasing even more the O2 level.
Now this year we are graduating to either nitrogen or argon, which have distinct advantages over CO2 in that they don't mix with O2 so well and therefore blanket better. Outside of doing our last year's process as is with the new gas, does anyone have any builds or advice?