gravity and/or surface tension in tubing

[MapleME]

Well, I thought i would throw this out to you physics gurus on the trader;

Last year I had many 5 gallon buckets on individual taps with tubing running from the tap through the top of the bucket, and it extended in to the bucket maybe 6 inches or so.

A few days I came home and the buckets were full (i.e. above the end of the tubing hanging in the bucket) and say was backed up the tubing to the tap.

I guess my question is
1. is this bad to have it backed up
and
2. Was it just gravity forcing the sap down the tube and letting the sap level rise above the level of the tubing, or do I risk having buckets not completely full on some trees by having extra tubing in the bucket.

My thought behind the extra tubing was I was on 3 feet of snow at the start of the season and at the end of the season I was on grass. A few tubes I cut too short and had to extend.

MapleME

[Haynes Forest Products]

When I first used a vacuum system I made a manifold that was piped out of the bottom valve on the Zero tank. I had the vacuum connected on the top cover. DIDNT WORK! I was trying in theory to lift all the sap in the tank to create vacuum in the lines.
I think what is happening is as the sap fills the bucket the level gets greater that the inlet tube hight it causes back pressure and slows down the flow. It could be the air/gas from the tree that is traped in the 5/16 that is holding that sap.
Liquid should seek its own level..........BUT I would just put the bucket farther from the tree to create slope and as the snow melts bring them back in.

[TapME]

MapleME; I did the same last year and believe me the buckets will over flow if the sap is running. Try not to put the end in so far use a cloths pin or another fitting at the end so that it is not so far in. I had many over flowing buckets last year.
The other thing is how can the sap be running at your place and nothing here. I'm jealous. TapME

[MapleME]

Ohhh noo, Lou, nothings running yet! Just getting ready!
Ill call you tommorow eve, see if we can link up over the next 2 weeks. J

[petersp22]

I saw the same thing when I used taps with tubes into buckets last year. When the sap level in the bucket hit the end of the tube I thought it must be holding pressure in the tube. Might that pressure in the tube have the opposite effect of vacuum? So I took a small drill bit and vented the tube near the tap. I'm interested to hear what others think as I might not have done real well in physics...

I like the idea of using a clothespin to hold the tubing above the sap level in the bucket.

[TapME]

You guys Royalmaple thought me if you put a fitting in the top of the bucket (a tap that you use in the tree) all you have to do is drill a hole the same size as the tree hole in the top of the bucket and push the fitting in to it. worked great for me last year and will use it again this year. The hole is 5/16th. To me the lids a dispensable cause I use buckets all the time, and one with a hole in the side doesn't hold water to that point. Just my way of doing things.

[Bucket Head]

MapleMe,

Were the lids on these buckets on tight? If so, thats probably the problem. The tree does not create enough pressure to force trapped air out of the bucket.

When we used buckets and tubing, we did it like TapMe did. We drilled a hole in the bucket lid, small enough that the tube was a very tight fit into it. That prevented rain water from getting in. It also was tight enough that when we pushed the tubing in, say an inch or so, it stayed at that height.

We always had to weight the buckets down, with a brick, patio block, or a rock. So we never put the lids on tight. We just set them on the pail and the weight kept everything in place. Well, it worked great except for the very high wind days, but no buckets stay put on those days!

This way no air gets trapped inside, and the buckets fill completly. And with the tight fitting tube/lid, when your buckets take off in the wind, your lid will be dangling from the tree by the tube. So you only have to round up buckets, no lid chasing!

Steve