Other Vacuum degassing is the only way to go

[vacuumpumpman]

I pull my hose connection so the the back flow comes from straight air instead. It isn't something I like doing though. I'm considering a check valve or where it will pull air though a filter. .

I believe what Paul is mentioning is that you get an oil mist per say coming out of the exhaust side of the oil filled vacuum pumps. That is why alot of us use oil less vacuum pumps.

You do not notice it at first , until you walk back in the room and see how hazy the entire room is.

 

[meadmaker1]

Actually, glass carboys are quite strong. I have evacuated them effectively as low as you can go, to no ill effect. (I am a vacuum guy.)

Personally, I do not favor using oil-sealed pumps on wine, due to not wanting backstreamed oil vapors in my wine, but whatever floats your boat!

Im not worried about oil going backwards through my j b pump it woud not serve it s havc purpose if it did..
It will however mist oil out the handle.
I use an oiless myself it s smaller quiter and was free.
I would probably use an old JB if it were all I had and tie a rag around the handle. Or pumb it from a remote location.

 

[Johnd]

I use a vacuum pump, which contains oil, the discharge is fitted with a damp towel, no airborn oil discharge at all. It also has a one way valve on the suction line, it doesn't backflow at all.

Having vacuum degassed carboys down to 29 inHg hundreds of times with nary an implosion, I would, however, not vacuum a carboy that had any kind of crack or structural defect.

Vacuum away at 75F, it works, period.

 

[meadmaker1]

A bought a cork that was bigger so it wouldn't get sucked into the car boy with my oilless. Not sure what it will pull but I usually stop when my clear tube is sucked flat. Then leave it till it opens back up.

 

[sour_grapes]

Actually, no, I was not talking about the oil mist that comes from the exhaust port. "Backstreaming" is the effect of oil migrating away from the inlet port of the pump, towards the carboy. You may not think this can happen, but it can indeed happen at low pressures. Think about it: the molecules, including oil molecules, don't know which direction the pump is. They just bounce around inside the tube; the molecules are more likely to wind up at the pump side than the carboy side because the pump keeps removing molecules from the pump side of the tube. However, some of them, including oil molecules, may bounce their way all the way to the carboy end.

 

[vacuumpumpman]

Actually, no, I was not talking about the oil mist that comes from the exhaust port. "Backstreaming" is the effect of oil migrating away from the inlet port of the pump, towards the carboy. You may not think this can happen, but it can indeed happen at low pressures. Think about it: the molecules, including oil molecules, don't know which direction the pump is. They just bounce around inside the tube; the molecules are more likely to wind up at the pump side than the carboy side because the pump keeps removing molecules from the pump side of the tube. However, some of them, including oil molecules, may bounce their way all the way to the carboy end.

Yes I totally agree - ^^

Yes I have heard of "Backstreaming" also -I never thought it could happen until someone explained it to me

 

[Johnd]

Actually, no, I was not talking about the oil mist that comes from the exhaust port. "Backstreaming" is the effect of oil migrating away from the inlet port of the pump, towards the carboy. You may not think this can happen, but it can indeed happen at low pressures. Think about it: the molecules, including oil molecules, don't know which direction the pump is. They just bounce around inside the tube; the molecules are more likely to wind up at the pump side than the carboy side because the pump keeps removing molecules from the pump side of the tube. However, some of them, including oil molecules, may bounce their way all the way to the carboy end.

I don't doubt the scienctific theory at all, just doubt that it'll occur in practice, when all of the variables are considered. Said confused molecule would have to travel through the 3 + feet of tubing, a check valve, and a catch reservoir, get through a tiny hole in the reservoir, back into and through another 3' of tubing, and into the carboy. I get that while the max vacuum is in place, the valve is open and there's little flow direction, but that is an instantaneous scenario, as gas coming out of solution on the other end quickly shuts the check valve as soon as the pump is stopped. After doing this hundreds of time, I just have never had any indication of this occurring.

 

[AZMDTed]

I don't doubt the scienctific theory at all, just doubt that it'll occur in practice, when all of the variables are considered. Said confused molecule would have to travel through the 3 + feet of tubing, a check valve, and a catch reservoir, get through a tiny hole in the reservoir, back into and through another 3' of tubing, and into the carboy.

I tried the same explanation with a girlfriend in high school

 

[sour_grapes]

I don't doubt the scienctific theory at all, just doubt that it'll occur in practice, when all of the variables are considered. Said confused molecule would have to travel through the 3 + feet of tubing, a check valve, and a catch reservoir, get through a tiny hole in the reservoir, back into and through another 3' of tubing, and into the carboy. I get that while the max vacuum is in place, the valve is open and there's little flow direction, but that is an instantaneous scenario, as gas coming out of solution on the other end quickly shuts the check valve as soon as the pump is stopped. After doing this hundreds of time, I just have never had any indication of this occurring.

You are correct that the factors you cite work to your advantage to lower the risk of backstreaming. I am glad it has worked out for you so far. If you're happy with your approach, I'm happy. As I said in my original post -- whatever floats your boat!

 

[Johnd]

You are correct that the factors you cite work to your advantage to lower the risk of backstreaming. I am glad it has worked out for you so far. If you're happy with your approach, I'm happy. As I said in my original post -- whatever floats your boat!

I totally agree, and wasn't being contrary just to be contrary, I'm a steadfast believer, but always with an opening for learning.

When my little electric pump eventually burns out, and since my wines all sit for so long anyway, I'll be replacing with one of Steve's rigs.