Two batches of wine + one secondary fermenter = I don't know what to do

[koolmoto]

But it is just not true as a practical matter. The settling effect due to the greater weight of Ar compared to N2 or O2 is completely, completely dominated by the thermal agitation at room temperature. It is like having a cardboard box full of tennis balls and racquetballs, and shaking the hell out of the box, and expecting to find only tennis balls at the bottom because the tennis balls are slightly heavier.

Previously, I had posted the calculation of the expected enrichment of Ar at the surface of the wine in a carboy at equilibrium, compared to just the ratio of the constituents. In other words, if you mixed 50% Ar and 50% O2 in a carboy, what would you expect to find (according to the laws of physics) at the surface of the wine? I cannot find the post right now, and I am too lazy to re-do the calculation, but it was something like 50.00005% Ar and 49.99995% O2. That is the extent of the "theoretical lessening of the mixing effect" that you allude to above. So, yes, it is less, but it is negligibly so.

And by the way, regarding your chart above, you don't have nitrogen or oxygen in your headspace, you have N2 or O2, so they are 28 and 32 g/mol, respectively.

Ah, very interesting! Thanks for the knowledge. So is what this guy doing in this video BS or is bottle sparging a different concept? (This is where I got the notion above)
Advanced Winemaking Techniques: Bottle Sparging
The Home Winemaking Channel
Here is a simple trick to extend the shelf life of your homemade wines and reduce risk of any in-bottle oxidation. Bottle Sparging is the process of pre-filling a bottle with inert gas before filling with wine. This displaces the oxygen and leaves you with only the inert gas consuming the airspace of the bottle. To perform bottle sparging you will need either a Nitrogen or Argon tank and a length of small hose to fit into the bottle. Make sure your regulator is capable of very low flow rates (around 1 lpm).

 

[sour_grapes]

I am not sure how to be more clear. Here was my first message (emphases added):

Although argon is useful for displacing oxygen from a headspace, I wanted to let you know that there is no such thing as an argon "blanket." Gases diffuse and mix readily after just a few minutes. In other words, if there is any oxygen in the headspace, it will have free access to your wine.

It takes ~hundreds of seconds for the gases to interdiffuse. If you sparge, as in your video, you can indeed successfully displace the oxygen from the headspace. However, Ar is not a "blanket," as you have called it. It provides no long-term barrier against other gases. If you get all the O2 out, then seal the vessel, then there is no O2 to get to your wine. If you leave any O2 behind, the Ar will confer no protection against it after about a minute. If you dilute the O2 down to a small amount, that is better than not diluting it, but whatever is left can "see" your wine.

 

[koolmoto]

I am not sure how to be more clear. Here was my first message (emphases added):




It takes ~hundreds of seconds for the gases to interdiffuse. If you sparge, as in your video, you can indeed successfully displace the oxygen from the headspace. However, Ar is not a "blanket," as you have called it. It provides no long-term barrier against other gases. If you get all the O2 out, then seal the vessel, then there is no O2 to get to your wine. If you leave any O2 behind, the Ar will confer no protection against it after about a minute. If you dilute the O2 down to a small amount, that is better than not diluting it, but whatever is left can "see" your wine.

Ah, sorry, I understand where the confusion is stemming from. Blanket is a bad term because the top of the "blanket" is not defined. I was always thinking the top of the blanket was at the bung, but you were thinking I was inferring the blanket was only taking up 50% of the air volume. I figured the heavier gas would stay in the carboy longer to give you more time to place the stopper before it seeped out. Perhaps that difference is not substantial, but that's why I went with Argon as opposed to Nitrogen.

 

[sour_grapes]

Ah, sorry, I understand where the confusion is stemming from. Blanket is a bad term because the top of the "blanket" is not defined. I was always thinking the top of the blanket was at the bung, but you were thinking I was inferring the blanket was only taking up 50% of the air volume. I figured the heavier gas would stay in the carboy longer to give you more time to place the stopper before it seeped out. Perhaps that difference is not substantial, but that's why I went with Argon as opposed to Nitrogen.

Okay, glad we are on the same page. Because one of the options the OP was discussing was fermenting in an open crock, you can see where I got that idea.