Very Simple Sap Lines

[DrTimPerkins]

But somehow the effectiveness of the sap column and or the flow of the lower taps/drops within the column seem like they are being hindered.

The lower taps will mostly be "hindered" by the lack of vacuum. In other words, the pressure differential from the inside of the tree to the tubing is much lower compared to the taps higher up on the hill getting strong vacuum. Since sap flow is linearly related to vacuum level, it is not unexpected that the trees lower down (not getting much if any vacuum) will run far less.

[DrTimPerkins]

Hmm... I might have a basic assumption that's wrong.

Rather than go into a lot of detail, a quick analogy might be simpler.

Say you have a 3/16" line, 100' long, with one end plugged. You suck on the end with one big breath....what is the vacuum you can achieve?

Do the same thing with a 5/16" line set up the same way. One big suck....the vacuum you'll achieve will be less because you weren't able to suck out as much (as a total volume of the tube) air. Bigger lines = more air to remove to get the same level of vacuum.

[DrTimPerkins]

I kept thinking of slope as degrees, but it is two different things, which helps.

But they are related. It is the total elevation drop that is filled with fluid (minus whatever is filled with air) that determines the maximum amount of vacuum that can be generated. However if your slope is too low, frictional forces start to subtract from that. On low slope or flat ground, friction is too high, and totally negates any vacuum generated (even if you have a really long line with good amount of drop), and can even result in the build up of pressure. This is why 3/16" tubing is not suitable for low slope or flat ground. With good slope and good elevation drop 3/16" tubing is ideal...as long as you keep it clean.

[Swingpure]

But they are related. It is the total elevation drop that is filled with fluid (minus whatever is filled with air) that determines the maximum amount of vacuum that can be generated. However if your slope is too low, frictional forces start to subtract from that. On low slope or flat ground, friction is too high, and totally negates any vacuum generated (even if you have a really long line with good amount of drop), and can even result in the build up of pressure. This is why 3/16" tubing is not suitable for low slope or flat ground. With good slope and good elevation drop 3/16" tubing is ideal...as long as you keep it clean.

If you have the first third of the 450’ very steep (7 taps), the middle third, shallow (3 taps), but still sloped and the final third (0 taps) with about a 10 to 15° slope, should that work, or does the middle portion kill the whole thing?

[Sugar Bear]

If you have the first third of the 450’ very steep (7 taps), the middle third, shallow (3 taps), but still sloped and the final third (0 taps) with about a 10 to 15° slope, should that work, or does the middle portion kill the whole thing?

The middle part should not kill it but...

The best place for the very steep section would be where the sap column forms. The steeper that column is the better off you are. Your sap column should form from the collection barrel up and how long it gets is determined by how well the sap is flowing and the number of taps.

The slope where the taps are is not nearly as important.

Mine have been about 60/70' long at maximum flow generating 17 inches ( also my maximum ).

[Swingpure]

The middle part should not kill it but...

The best place for the very steep section would be where the sap column forms. The steeper that column is the better off you are. Your sap column should form from the collection barrel up and how long it gets is determined by how well the sap is flowing and the number of taps..

I actually walked the lines today, and I by passed some lower trees to make sure I had the “crux”. One of the two lines finishing off with an 80’ uninterrupted stretch at 35° slope and the second line finishes off with a 125’ uninterrupted stretch at a 25° slope. This line actually runs by a viable tree, but the tree is only 30’ from the collection area. I will put a bucket on that tree.

Both collection buckets are side by side and the wire that holds the end of the line, will hold both line ends.

[DRoseum]

No harm at all in including that final tree. You will get more out of it on tubing than a bucket and it won't reduce yield of upper taps at all.

[Swingpure]

No harm at all in including that final tree. You will get more out of it on tubing than a bucket and it won't reduce yield of upper taps at all.

Actually it might be a good test. Both lines start at identical elevations, literally feet away, and both end up at the same location. It would be interesting to see how each kine averages out, although the other line has more trees with greater diameter.

[DrTimPerkins]

Actually it might be a good test. Both lines start at identical elevations, literally feet away, and both end up at the same location. It would be interesting to see how each kine averages out, although the other line has more trees with greater diameter.

If the trees are different sizes, it will not be a particularly good test. Tree size has a strong influence on yield, so any effect will be swamped out one way or the other. For it to be a "good" test, you'd need a bunch (10-20 minimum) of nearly identical lines (same number of trees, same average diameter, same slope, same aspect, etc.), half set up one way and half the other.

[Swingpure]

This may sound like a silly question, but when you start to tap the trees and hooking up the drops on the line, do you work at the highest elevation down, or at the bottom of the run, upward? I can make an argument for both ways.

Thanks