Mainline Question

[n8hutch]

200 ft of 3/16 tubing is what 13$,5 minutes to walk the extra 200 ft is 2.50$ 1 tap at even today's bulk prices would pay say 40 dollars over 5 years, how would it not pay for itself, retail your talking 150 dollars gross income from that 1 tap . I guess I'm missing something especially if that tap is doing nothing because of pack pressure.

[wnybassman]

Hi Noel,

Doug Beitz here over in Attica. I have nearly 2,000 3/16ths all of them running into a mainline ranging from 3/4" to 1 1/4". I do have one or two individual 3/16 running into my tank to gather the lower elevation trees in comparison to my tank. You are more than welcome to come check it out any time you'd like. Give me a call if you'd like 813 6623

Thanks! I may just do that. I grew up in Alexander so I am pretty familiar with Attica too. I've been pretty busy but I think my schedule will loosen up in a few weeks.

[DrTimPerkins]

I see no issues in that as I run up to 25 taps per lateral line and if the last tree only gets 3' of drop to the mainline, then it goes on the lateral.

As long as you have a good elevation drop and keep the system leak free you'll generate decent vacuum. The issue is related to low slope applications only. A drop line will get you a little vacuum (but not much additional sap yield from it for other reasons), but then you loose it in the lateral lines that run across flat areas.

The easiest analogy is that it is like a kid sledding down a hill. As long as you have good slope, gravity is pulling you down and can overcome any friction so that you're sailing along just fine (this downward movement generates vacuum behind it -- in a tight system). When you hit a flat area, friction slows you down (so you lose the vacuum you had). If the flat area is just a short distance, you can sail through it and continue down the hill behind. However if the flat area is too long, or if you start out on flat ground, you just aren't going to go anywhere (will generate no vacuum, or not enough to overcome friction -- in fact, the weight of the sled -- or sap -- makes it somewhat more difficult to overcome friction and get things moving -- creating backpressure on any sap trying to enter the line from the tree).

We can extend that analogy a bit further if we wish. The kid starting at the top of the hill has the most momentum and will go the furthest at the bottom (has the most vacuum). A kid starting half way up will have about half the momentum (vacuum). A kid starting 3' up the hill won't go real far (little vacuum). A kid starting at the bottom won't go anywhere (no vacuum). In order to get that kid moving, we either need somebody to push them (pressure within the tree) or somebody to pull them (vacuum in the line from a pump). But because the kid at the bottom has some friction (bottom of the sled hitting the snow, or sap moving in a small diameter tubing line), it takes a bit of force to get them going, and you'll have less vacuum differential at the tree, and thus slightly less sap yield since it is the vacuum (pressure) differential that creates sap flow, and sap yield is strongly and linearly related to pressure differential (5% more sap per 1" Hg vacuum).

Hopefully that makes sense.

[WESTVIRGINIAMAPLER]

Dr Tim,

I agree that 30' past last tap is ideal, what I was referring to is that some guys run each lateral lines hundreds of feet along side of mainline to get 30' of drop past last tap. With mainlines mostly 2% to 5% slope, this results in tons of additional lateral line length to get that 30'. I agree there will probably be a little more sap but on a cost analysis, I don't see the benefit. Yes, it sells more tubing but at the end of the day I don't think it's best installation or best for customer.

[DrTimPerkins]

Yes, it sells more tubing but at the end of the day I don't think it's best installation or best for customer.

I agree. The cost benefit ratio can be marginal under those circumstances.

[wnybassman]

As long as you have a good elevation drop and keep the system leak free you'll generate decent vacuum. The issue is related to low slope applications only. A drop line will get you a little vacuum (but not much additional sap yield from it for other reasons), but then you loose it in the lateral lines that run across flat areas.

The easiest analogy is that it is like a kid sledding down a hill. As long as you have good slope, gravity is pulling you down and can overcome any friction so that you're sailing along just fine (this downward movement generates vacuum behind it -- in a tight system). When you hit a flat area, friction slows you down (so you lose the vacuum you had). If the flat area is just a short distance, you can sail through it and continue down the hill behind. However if the flat area is too long, or if you start out on flat ground, you just aren't going to go anywhere (will generate no vacuum, or not enough to overcome friction -- in fact, the weight of the sled -- or sap -- makes it somewhat more difficult to overcome friction and get things moving -- creating backpressure on any sap trying to enter the line from the tree).

We can extend that analogy a bit further if we wish. The kid starting at the top of the hill has the most momentum and will go the furthest at the bottom (has the most vacuum). A kid starting half way up will have about half the momentum (vacuum). A kid starting 3' up the hill won't go real far (little vacuum). A kid starting at the bottom won't go anywhere (no vacuum). In order to get that kid moving, we either need somebody to push them (pressure within the tree) or somebody to pull them (vacuum in the line from a pump). But because the kid at the bottom has some friction (bottom of the sled hitting the snow, or sap moving in a small diameter tubing line), it takes a bit of force to get them going, and you'll have less vacuum differential at the tree, and thus slightly less sap yield since it is the vacuum (pressure) differential that creates sap flow, and sap yield is strongly and linearly related to pressure differential (5% more sap per 1" Hg vacuum).

Hopefully that makes sense.

I think that's what I had going on this season. Because we bought that land so late in the fall, we didn't really have time to do anything drastic, and I tapped the upper half of the trees and ran lines directly into a cage tank halfway down the hill. For the record, this property slopes away from the road so everything has to be pumped up to the road. Out of the 6 lines I had going into it, 4 of them had a long gradual run traversing across the hill to get to the tank, although all of the runs had good slope leading up to that long traverse. There was only one day did I have a gallon per tap run, most times it was a 1/2 gallon or less. I really felt that flat at the end hurt my production. I think a mainline will help prevent that scenario at the bottom of the hill also.

[DrTimPerkins]

I really felt that flat at the end hurt my production. I think a mainline will help prevent that scenario at the bottom of the hill also.

Very likely that did lessen your production, and as long as you can get some amount of slope (even a minimal amount), then I'd switch to mainline for the flat section.

[wnybassman]

I decided to stick with the mainline route.

I have a driveway that can be used during the driest months of the summer that I will need to remove a section of it though. Planning on Banjo cam lock fittings for this section, just wondering if I can get the tension on the pipe with these fittings once things are tightened back up?

[mainebackswoodssyrup]

Find the best spot on either side of the drive for than banjo fittings (where you have a good tree to tension to) and leave a couple feet of mainline either side of the fitting untied from the wire so the banjos aren't under too much tension. They seem to always leak some as it is so you definitely don't want them pulling against each other. We wrapped wire around the tree from both directions and connect/disconnect the banjos as needed by having a couple feet to work with either side of the fitting.
That is, until this year when we raised the line up, got the clearance we needed and got rid of the banjo fittings that were both leaking. My first suggestion would be to look at that and see if its possible. if not, banjos work good but they leak over time so keep an eye on them. I'm not sure they seal 100% no matter what you do.

[Maplewalnut]

I see no issues in that as I run up to 25 taps per lateral line and if the last tree only gets 3' of drop to the mainline, then it goes on the lateral. I run everything that way and with customers also. Will you get more sap running the lateral line along the mainline for several hundred feet to get the 30' drop? Yes, probably but it's the old expression "robbing Peter to pay Paul". You have higher installation cost doing it that way and you also have a lot more lateral line to maintenance and repair. I see really great sap per tap numbers getting it into the mainline as quick as possible. Yes, I run nearly all lateral lines into mainlines. I'm not sure the extra thousands of feet of lateral line tubing will ever pay for itself in more sap, especially if you figure labor into the equation with installation, repairs and maintenance.

Good thread in the off season. I'll jump in with another question.... so if back pressure and minimal slope are a concern with the taps closest to the mainline that have little elevation drop on 3/16ths...would it be better to hook up any low elevation trees conventionally with 5/16ths into a separate mainline saddle and whatever you get gravity wise is more than not tapping them at all

thanks
Mike