3/16" Tubing layout question

[maplestudent]

Hi Everyone. First I'd like to say a warm Thank You to all the people that have posted and shared their knowledge on this site.

I've read Tim Wilmont's research on 3/16" tubing and also several threads here, and am thinking I'd like to try it on some of my trees. I'm not sure how I should do the layout though. Most of my trees are red maples, and I'm hoping I can coax a little more sap from them; some are particularly stubborn. I have two groupings of about 7 trees each where I believe I can achieve an overall drop of between 20 to 25 feet (for all trees) with a slope of up to about 17% if I went straight down the hill. The trees at the highest elevation in each group, and thus the end of each line, are probably 125 from each other. The trees at the lowest elevation in each group are probably about 50 feet from each other, therefore the lines will more or less approach each other. From the bottom of that hill, I can continue at a minimum slope for another 200 feet to where I'd ultimately like to have my sap storage. In addition, there are more trees that I could conceivably add, both near the bottom of the 17% slope hill, and also along the 200 feet of minimal slope. My interpretation of Tim Wilmont's research is that zig-zagging lines appear to have better results than branching lines, and I'm not quite sure I understand the properties of how the vacuum works if I wanted to add trees at the bottom of the 17% slope or along the 200 foot run to storage tanks. So, my questions are:

1. Would it be best to keep the lines from the two groups of trees separate until the bottom of the 17% slope, or would it be okay to combine the two lines, after which I'd still have about a 20 foot drop?

2. When the lines get to the bottom of the 17% slope.....would continuing the lines unbroken all the way to the storage affect the amount of vacuum, or would it be better to end the vacuum at the bottom or the 17% slope hill, say into something like a dump station bucket, and then run a separate line to the storage tank?

3. If I added trees that are near the bottom of the 17% slope, I realize that they will not achieve the same amount of vacuum as those at the top of the hill, but will adding them jeopardize the amount of vacuum that I might achieve at the top of the hill?

4. Along the 200 foot run to the storage tank, I have another 15 to 20 trees that could be added, with minimal slope to the tank. Tubing would mostly be a convenience thing. Should I run these totally separate from the trees on the hill? on 5/16" tubing instead of 3/16"? can too much sap in the portion of a line with minimal slope hinder the achievable vacuum at trees that are on the same line but on the hill?

I'm not sure my budget will allow me to get all of these trees on tubing this year, but I'd like to approach this in a manner in which I could build upon in future years, starting with the trees on the hill. I also have more trees on the other side of the hill that I don't plan to tap this year, as I don't have any sort of mechanical woods transportation to aid in collection, but could possibly tap with buckets and do the manual labor thing and carry to a future dump station at the top of the hill.

Thanks, Any suggestions are greatly appreciated.

[steve J]

Well I am not an expert on this although I have installed 3/16th for this season. You do not want to join these two lines together because vaccum is created in each line and if you introduce a Y from what I understand that would become a bit of a log jam and slow your sap down. I think and maybe others here have another opinion but maybe what you need to do is run a 3/4 main line to the bottom of that slope and connect your 3/16th to that and have that run to your storage tanks but also join on 5/16th lines in the area were you said there were other trees.

[maplestudent]

Steve J

Thanks for your reply and for your alternative suggestion.

One thing I should have mentioned is that I'd like to create a setup that I can set up and take down each year. For that reason I'm trying to avoid a larger sized mainline, because my understanding is that it would need a support wire. One of the reasons I phrased my questions the way I did was to try to develop an understanding of the resulting properties that are created in a system when various things are done, such as your answer about the "log jam".

However, I will certainly keep your suggestion in mind while I try to figure out what I want to do.

Thanks for your input.

[maplestudent]

After doing more research, seems to me that for the two groups of trees on the hill, it would be best to run two separate 3/16 lines to the bottom of the hill, like Steve J suggested. I have about 8 or 9 trees at various elevations that are near the bottom of the hill (but not at the bottom) that could be added to these lines. Tim Wilmont's paper indicates the trees near the bottom of the slope would not have much vacuum, but doesn't say anything about whether or not such trees would help or hinder the overall flow of sap from all the trees on the line or have any specific affect on the vacuum at trees at the top of the hill. Though it would seem that if they could add sap to the column with at least some drop below them, they would be of benefit, but if there was minimal drop below them, they might cause some stagnation in the line.

Any thoughts on this theory?

[lpakiz]

A good way to find out would be to cut in a tee at one of the lower trees. If sap squirts out on a heavy run day, you have pressure, don't hook on another tree-you are past capacity. Now if it pulls air in, you have SOME vacuum. Not as much as higher up the line, but some.

[maplestudent]

Excellent idea. Thanks for the suggestion