rjquillin wrote:If you subscribe to the vacuum thing to help preserve your partial bottles, this should nicely do the trick at a very attractive price.

Well done!

bhodilee wrote:Well done!

Yes, guilty, but I ~really~ wanted to see what made this work, so..


I found a way!

Kind of an exploded view of the parts I could get to without destroying the device. Right to left: outer case, plunger assembly, spring, O-ring (fits in a grove between the dark rim at the right of the milk colored assembly to the left, pump valve assembly and housing (with a truly large amount of silicone grease, silicone bottle gasket.

Inside the valve assembly there is a silicone rubber valve piece the moves to block inlet and exit air as the pump button is depressed and released.

Close up of the bottle end of the valve assembly and bottle gasket.
The bottle gasket fits over the center post of the valve assembly.

Yes, it did successfully reassemble, and yes, it does still work.

That's all fine and well, but can you tell us the air-speed velocity of an unladen swallow?

rjquillin wrote:Hey, mods, I want the old "lab rat" header for this one!
If you subscribe to the vacuum thing to help preserve your partial bottles, this should nicely do the trick at a very attractive price.

This is absolutely the best analysis and review of one of these products that I have ever seen. Given the reduction in absolute pressure I would expect to see a significant reduction in oxidation (rate of reaction when a component is in the gasseous phase in direct relation to the partial pressure of that gas, in this case oxygen). In for 2.

rjquillin wrote:Personally, I use a tank of Argon

Sent you a pm. Thanks.

tomatillo wrote:Sent you a pm. Thanks.

replied, and for others interested, check THIS for a pic of what I use with additional discussion HERE .

I still say save the money, put the cork back in, put it in the fridge.

..other than the aforementioned gas maybe.. but for a day..cork it..

RJ, some ignorant layman-style questions about your lab analysis...

I noticed that the Convectron gauge is calibrated for N2, does this mean that N2 was displaced instead of O2 in the experiment? If so, and knowing that Oxygen is slightly heavier than Nitrogen how do you expect that difference would affect the overall numbers?

Also, it appears that your numbers are converted to PSI and that the effectiveness of the gas displacement is based upon pressure change as opposed to actual volume displacement, is there a direct correlation?

Also curious if you did any additional pumping after the initial 20-25x on the Convectron gauge and remeasured to see if there was a difference in the reading? Would love to know the ideal number of pumps for this item since it does not have the tell-tale "click" of the Vacu-Vin which lets you know when to stop.

My apologies if my questions are silly due to the fact that my grasp on the subject material (particularly the research methods involved) may be lacking.

Thanks for your efforts!

chipgreen wrote:RJ, some ignorant layman-style questions about your lab analysis...

I noticed that the Convectron gauge is calibrated for N2, does this mean that N2 was displaced instead of O2 in the experiment? If so, and knowing that Oxygen is slightly heavier than Nitrogen how do you expect that difference would affect the overall numbers?

We use N2 as a purge gas for our thermal-vac chamber and these gauges only for rough vacuums as we transition to/from our mechanical roughing pump to either a turbo or diffusion pump. N2 is what, ~78% of our atmosphere. We are removing 'air'; ~78% N2, ~21% O2 and ~1% Ar. Being too lazy to actually calculate what the error may be I think at the pressures we are dealing with absolute error is negligible, the gauge just happens to be calibrated for N2.

Also, it appears that your numbers are converted to PSI and that the effectiveness of the gas displacement is based upon pressure change as opposed to actual volume displacement, is there a direct correlation?

We're not really 'displacing' gas here as much as removing some volume. My Argon rig actually does displace atmosphere with inert Argon that has a higher mass/volume than standard atmosphere, and covers the surface of the wine with a non-oxidative gas. Here I converted to psi for the masses that are most accustomed to dealing with those units. It was not convenient to attempt to measure volume, but perhaps pV = k could supply an approximation. The lab was 22C. Actual volume will obviously be affected by how full/empty your container is. I really think it's pressure we're interested in here.

Also curious if you did any additional pumping after the initial 20-25x on the Convectron gauge and remeasured to see if there was a difference in the reading? Would love to know the ideal number of pumps for this item since it does not have the tell-tale "click" of the Vacu-Vin which lets you know when to stop.

If you have/get one of these, there is a pretty obvious change in the tactile feel and sound as you pump down a bottle. One should have little difficulty knowing when effective pumping has ceased. The gauges confirmed minimal if any improvement when continued pumping sounds/feel were unchanged.

My apologies if my questions are silly due to the fact that my grasp on the subject material (particularly the research methods involved) may be lacking.

Thanks for your efforts!

Eh? Not at all. This was actually a hoot (woot!) and great diversion from what is normally a pretty mundane day.

Awesome, thanks for the additional clarification. I have a better understanding now.

One final question, do you think that the ratio of removed air (not displaced, haha) would change based upon how much wine was left in the bottle? Or do you expect that it would still be about 1/3?
EDIT: above question based on comment; "Actual volume will obviously be affected by how full/empty your container is."

chipgreen wrote:Awesome, thanks for the additional clarification. I have a better understanding now.

One final question, do you think that the ratio of removed air (not displaced, haha) would change based upon how much wine was left in the bottle? Or do you expect that it would still be about 1/3?
EDIT: above question based on comment; "Actual volume will obviously be affected by how full/empty your container is."

I believe you need to think solely in pressures.

rjquillin wrote:I believe you need to think solely in pressures.

ok, do you think that the reduction in pressure would still be about 1/3 regardless of how much wine is left in the bottle? I love the way you deconstructed and analyzed this. It's amazing how technical and involved one can get with something that seems so simple on the surface.

chipgreen wrote:That's all fine and well, but can you tell us the air-speed velocity of an unladen swallow?

African or European?

chipgreen wrote:ok, do you think that the reduction in pressure would still be about 1/3 regardless of how much wine is left in the bottle? I love the way you deconstructed and analyzed this. It's amazing how technical and involved one can get with something that seems so simple on the surface.

Yes, with constraints. I believe it will be limited by the maximum differential pressure the pump mechanism is able to maintain. I've seen ~5 psi at sea level. Were this to be used, say in Denver, where the absolute pressure is closer to 12 psi rather than the ~14.7 psi at sea level, it may still pump to a ~5 psi differential, but as elevation is increased from sea level, at some point I would expect efficiency to drop off where that 5 psi would not be obtainable.

Regarding volume, as the internal pressure decreases, a diminishing number of air molecules will be removed per pump, and clearly the volume of air you need to remove will be determined by the "empty" space of your bottle and the required number of pumps will vary.

I would really liked to have been able to construct a setup where I could plot pressure vs. number of pumps; that would have been useful.