Very Simple Sap Lines

[DRoseum]

Why not put all 11 trees on a single run and tank just below the last one?

Also - reiterating... do not vent at the top of the run. That defeats the natural vacuum that is being put on the tap holes.

[Swingpure]

Why not put all 11 trees on a single run and tank just below the last one?

Also - reiterating... do not vent at the top of the run. That defeats the natural vacuum that is being put on the tap holes.

I may have misunderstood, when Sugarbear said:” You want no fittings of any kind mucking up a final run.” I was afraid of putting three fittings after the long 125’ “final” run.

[Sugar Bear]

Hmmm, I thought I finally had what I was going to do firmly in my head and that I could sleep at night.

So if I have a run of 8 trees, let’s say over a downhill distance of 150’, I should further extend the tubing 75+ feet downhill to create the final run and the vacuum? I have three trees about 125’ down from the last of the 8 tree run. Would I run the 3/16” tubing to a collection barrel down by the three trees, but not connect up to the three trees. And just have the three trees separately connect to the collection barrel?

Gary

I can't speak for 3/16 tubing and the hydro dynamics are definitely going to be different then 5/16". But If you were to use 5/16" tubing I would definitely do it this way. Unless you can pick up the three taps and go another 75' of tubing that drops 15' minimum from the last of those three low taps.

I have had a run almost identical to this with three taps at the bottom of the final run, T'd into the final run, just before the collection barrel.

Separated them mid season. Very significant improvement in flow rates.

A column of sap generating vacuum should be as straight and as long and as uninterrupted as possible.

The more taps the steeper the sap column can and or needs to be and the more inches of mercury it will generate.

1) Too few taps and too steep a a final run will not generate a sap column because it will run out too quickly and not build up in the lines. The flow rate in this scenario will be about the same as if you had all your taps on drops to individual buckets.

2) Too many taps and not steep enough of a final run will saturate and sap lock your tubing with sap. The sap won't run out fast enough because friction of the liquid in the tubing overrides the limited amount of gravity acting upon it. In addition a limited amount of vacuum generated in the system has negative effects on sap flowing out the tubing as well. These forces combined make for a run that is less efficient flow wise then taps on drops to buckets. ( you would be better off venting the tubing in this case at the top as it will bring you closer to a taps on drops to buckets flow rate )

Somewhere in the middle of 1 and 2 is a tightly sealed natural vacuum system that functions above taps on buckets. The only way to get a feel for this spot is through trial and error.

Vacuum gauges at the top of experimental runs are a MUST if you want to get a grasp on what works and what does not.

It is also important to be able to visually detect/feel tubing that is loaded with sap and tubing that is empty. I do this by putting a dip in my tubing with my hand, if the dip fills with sap the tubing at that location is still empty. If it does not fill it is because it is already filled and part of the existing sap column. I am always able to determine the exact length of my sap column by doing this.

[Swingpure]

1) Too few taps and too steep a a final run will not generate a sap column because it will run out too quickly and not build up in the lines. The flow rate in this scenario will be about the same as if you had all your taps on drops to individual buckets.
.

The best I can do is have 8 taps on a good steep grade, then have a long uninterrupted 125’ steep run to a collection barrel. I have two situations like that. I also have three five tree short runs.

Is the fact that I only have a maximum of 8 taps, negate any chance of vacumn gains, even with the long final runs?

[Sugar Bear]

The best I can do is have 8 taps on a good steep grade, then have a long uninterrupted 125’ steep run to a collection barrel. I have two situations like that. I also have three five tree short runs.

Is the fact that I only have a maximum of 8 taps, negate any chance of vacumn gains, even with the long final runs?

I have a run with 7 taps and a final run of about 80 feet and it vertically drops around 15 to 18 feet to the collection barrel from the lowest tap.

Last year I put a vacuum gauge at the highest tap.

During the beginning of the season when sap flow was slow I pulled about 10 inches of mercury ( a unit measure of suction ) on the gauge. I had about a 35 foot long column of sap in the final run of 5/16" tubing. ( mid afternoon ) That column ended where it was dripping out the tubing into the collection barrel and ended 25 feet up the tubing.

A couple weeks later, at peak of the seasons sap flow, I was able to measure a column of sap that was 75 feet long and gave me 17 inches of mercury at the gauge. Even more suction. My column of sap was almost up to the first taps. Just a few feet short of it. If I had a tap or two more my sap column would have been past it and it that situation my intuition tells me that I would have had too many taps on my run for that moment in time.

I would say if your sap column runs into your drops coming into your mainline ( in this case 5/16" tubing ) from taps, you have too many taps on your line. I don't think you want to sap swamp a tap hole in a vacuum situation. Although I am not certain of the drawbacks of that.

Too many taps at one point in the season may be too few at another point in the season for a specific run of tubing. It is dependent on how well the sap is flowing and how well the trees that you have tapped perform.

I will say that the 7 taps I have on my mentioned rig are saptual dynamoes.


In your case the 125' may be perfect. I would go with it. Put a gauge on the top. Make sure its tight. And look for that column of sap in the final run. If its there you will have inches of mercury on the gauge. Assuming you have no air leaks in your lines.

Sap column/suction will keep sap running longer into the freeze of evening however will eventually collapse and go away when sap stops flowing at taps. Collapsing column should pull all sap out of the run because of the hydro dynamics involved with "moving" sap, unless you have pronounced sags in the run.

As that say out on the river. Tight lines

[DrTimPerkins]

2) ...you would be better off venting the tubing in this case at the top as it will bring you closer to a taps on drops to buckets flow rate )

There is almost never a good reason to vent maple tubing. 1) You will lose any natural vacuum that might develop. 2) Venting pulls in air which contain microbes, which leads to faster taphole drying. Venting has been shown repeatedly to result in lower sap yields. The key is to have a slight amount of slope. Some liquid retained in the tubing when the run stops is normal in most cases.

[DRoseum]

Dr. Tim can weigh in, but I dont think adding the bottom 3 taps would have a negative effect on the upper 8. If anything it's more sap in the line and a slightly longer run, which would increase vacuum on those upper 8. Vacuum is generally proportional to drop/slope. My recommendation is put all 11 on a single line with your final tank as low as practical after your final tap.

[Sugar Bear]

There is almost never a good reason to vent maple tubing. 1) You will lose any natural vacuum that might develop. 2) Venting pulls in air which contain microbes, which leads to faster taphole drying. Venting has been shown repeatedly to result in lower sap yields. The key is to have a slight amount of slope. Some liquid retained in the tubing when the run stops is normal in most cases.

"almost never" denotes an exception. Could you describe that exception and what the circumstances would be for it?

[Swingpure]

I read a lot of articles and they all said to have a long, steep run after the last tap, as Sugar Bear had said. I am going to buy more tubing on Wednesday and I am rethinking how I will set up my lines.

I will also buy the single handed 3/16” tool at CDL. I did check out the tool at Mapletech tools and they did reply to me about shipping costs, but by the time it came across the border and the exchange, it was not any cheaper than CDL.

I still wonder about setting the lines up at the beginning of November before the snow flies, especially if some people leave them up all year round. We do have squirrels and chipmunks, but they are not overly active after November.

[DrTimPerkins]

Dr. Tim can weigh in, but I dont think adding the bottom 3 taps would have a negative effect on the upper 8. If anything it's more sap in the line and a slightly longer run, which would increase vacuum on those upper 8. Vacuum is generally proportional to drop/slope. My recommendation is put all 11 on a single line with your final tank as low as practical after your final tap.

Correct. As long as the bottom taps don't overload the lines, or as long as you don't have to cross a long flat stretch of ground, it would be fine to add them. They will not get any/much of any benefit of natural vacuum if there is little drop beyond them to the point of sap exit from the line, but it won't hurt either.