Benefits to gravity? Help me understand

[csk91]

Happy new year!
I have about 30 maple trees on my property and I live on the top of a hill so all of the trees are on some type of a downward slope. There is a 10-15 food drop in grade. Is there any benefit to trying to do a gravity set up for 2-4 trees in a run? Would there be a benefit to tapping a tree and having a 5-6 foot grade drop over 20 feet of 5/16 tubing before feeding into a storage container? Right now I just put leader check valve taps with 5/16 drops into 5 gallon buckets at the base of the tree. Just trying to determine if I could be “pulling” more sap out of my small property. Bought a new arch and nervous about feeding it.

[Sugarmaker]

Welcome,
Much, Much written about gravity and vacuum systems on 3/16 tubing systems. Your wont find much value on 5/16 for increased volume.
How big is your new arch? How many gallons is expected to boil per hour? How many taps do you have now?

Each tap in a good tree should produce approx 10 gallons of sap per season or about a quart of syrup. That is on just gravity buckets or 5/16 tubing/ The right 3/16 system in the right place might almost double that in theory.
Good luck with your season.
Regards,
Chris

[csk91]

Thanks for the reply. I have been reading but most of the information I am finding is about 20+ taps running in long 100 foot runs. I was wondering if there is a way to experiment with smaller runs using the tubing I already own. I have been using drops into buckets for 4 years. I have silver/swamp maples. I get about 3-5 gallons per week per tap when it’s running well. My sugar content is pretty low compared to a sugar maple.
I had a 16x30 flat pan on an insulated barrel stove. Going to a 20x48 Smokey lakes pan/arch. The pan is a flat pan divided into 3 channels so I can draw off as I go vs batch boiling. I think I’ll go from 5 gal per hour to 8-10.
In a good week I have over 100 gallons (so 10 hours of boiling minimum)... but on a down week I may only have 30 or 40 gallons... really looking to keep that low end number a lot higher or it is almost not worth the effort.

[therealtreehugger]

You said you live on the top of a hill - move your sugar making to the bottom of the hill, so you can have tubing go right into your storage tank. No more lugging buckets!!!! I didn't realize what a pain it was until I put up some tubing going directly to the sugar house!

[ronewold]

I'm very new to this, but I have done a ton of reading on doing natural vacuum tubing setup. 5/16 tubing isn't recommended for generating vacuum, 3/16 tubing is what people use. For every foot of drop from the tap to the tank, you can generate a theoretical 0.8 inches of vacuum, but you need to put a minimum of 4-5 taps on a single 3/16 line to get this to work. So with your 10-15 feet of drop, you could possibly generate 8-12 inches of vacuum, which would definitely help with sap production. If your trees are partway down the hill, some of this effect will be lost on them- and the trees at the bottom near the tank won't see any vacuum at all.
So if conditions are right at your place (majority of trees near the top and collection point near the bottom) and want to squeeze a little more production out of a limited number of trees, you might be able to get some benefit if you switch to 3/16.

[csk91]

Thank you. That is really helpful. I can get lower in grade if I move the collection point a few hundred feet away from the trees is there a downside to having a really long run after the last tree? Also would a switchback pattern or 180 degree turn as you zig zag the line create resistance in the flow defeating part of the gravity benifit? Does the run need to be in a general direction?

[buckeye gold]

That long run and fall from your last tree will actually help you create vacuum. Don't worry about turns and weaves. weaving in and out among threes helps keep tension on your lines. Just don't pinch it and your fine.

[mainebackswoodssyrup]

If you can collect at the bottom, run one 3/16" line from top to bottom with 5/16" drops and put all 30 taps on that one line. We have one bush that is 34 taps along a rock wall and we are trying 3/16" on it this year for the first time. Very similar to what you are describing. We have about 20' of drop in 500' so not max. vacuum but we should get some. Never know until you try. These trees are some of our best trees. If it doesn't work good, we'll replace the line for $50 next year with 5/16" tubing and some new tees (big deal!). Not going to bother with cleaning the line if it does work, will just replace the line after 3 seasons.

[maple flats]

With that drop you will do very well, having 25-30 taps on any 3/16 line in year 1. How you do in subsequent years depends on how well you clean the system, both soon after the season and then again mid-late fall. After year 1 there will be a "skin" layer left in the tubing which must be cleaned. If not removed that will have chunks scale off next year and will plug the fittings.
I have done well using 3/16 but I learned several tricks or steps to take. Soon after the last sap flow, wash the tubing using calcium chloride. It needs about 30 minute contact time to do a good job, then drain it out and flush well with potable water. (from the top) Then in mid to late fall, repeat. I also swap out every 3/16 fitting. I use 5/16 taps and drops, then all 3/16 laterals. Thus I use a new tap, tee and any connector in the line is changed for new. Mine are all also on good vacuum (26-27") and the connector before entering the mainline (a 3/16 x 5/16 connector) is changed. I've had good results doing this for 5 years now, but 2020 was down a little. 2016-2019 were all real good. This year I'll repeat the same.

[csk91]

Thanks since the run is so small and the tubing isn’t too expensive I think I could get away with just using it for one season. I was on bascom last night trying to figure out what I would need to buy in addition to the tubing. Got a little overwhelmed and backed off. Will go back today and see if I can figure it out. Might be too late for this season as I will be tapping in the next 3 weeks. We will see. Thanks for your help

[maple flats]

I wouldn't wait much longer, as more producers order their supplies inventories can and do get low. I just ordered from Bascom on Jan 2 (Saturday, ordered online late in the day. Order was shipped Monday. I only ordered 200 3/16 hook connectors, 300 3/16 x 3/16 x 5/16 tees, 100 5/16 hook connectors and 300 5/16 cv2 taps. Everything came, from Bascom to central NY in 2 days transit time.
I normally buy locally, but with Covid I order more online. I still had the rest of what I need, including about 250 drops I made 2 years ago.
If you are going to run tubing for the first time, you need a fitting for starting at the top tree, a hook or other designed for the tubing to go around the tree and connect back to the tubing. Then for each drop, you need a tap, a tee to join to the lateral and a length of tubing. At the downhill end you can run into a collection tank or if you have mainline, you need a hook connector and a saddle. Another method that can be used for both the top tree and at the bottom is some 1/4" hollow braid rope. To use that tie the rope around the tree, leaving a medium long tail. Then take a ball point pen apart and slide the point end onto the tubing and by pushing only force it up inside the center of the hollow rope. Once in 6-8" poke out thru the side and you have an adjustable Chinese finger to hold the tubing. I use 5/16 taps and drops on every tree, the tees are then 5/16 or 3/16 x 3/16 x 5/16 to connect the drop to which ever size the lateral is. The lateral is the tubing going from tree to tree.
csk91, I'm not sure any of us gave an answer to your original question, "the advantage of gravity". Gravity never breaks, it runs for free 24/7/365. Those are two more important advantages IMHO.

[buckeye gold]

You will have time to run your tubing. a couple days work and you'll have it. Two hints, if someone hasn't already made them. Make a spooler or at least run some pipe through the spool of tubing and spin it off as you go. Don't try and hold it on your arm and unwind it, you'll have loops and tangles and hate your life. Search threads here for spoolers. Also run all your tubing and then put in your tees and drops. So much easier that way. While at bascombs buy a tubing holder or make one to help with putting in tees, unless you spend the big buck for a tubing tool. A thermos of hot water will help you soften the tubing for tees. Be sure and get several straight repair couplers, you will have leaks and need to make repairs.

[csk91]

Thank you!

[maple flats]

You will have time to run your tubing. a couple days work and you'll have it. Two hints, if someone hasn't already made them. Make a spooler or at least run some pipe through the spool of tubing and spin it off as you go. Don't try and hold it on your arm and unwind it, you'll have loops and tangles and hate your life. Search threads here for spoolers. Also run all your tubing and then put in your tees and drops. So much easier that way. While at bascombs buy a tubing holder or make one to help with putting in tees, unless you spend the big buck for a tubing tool. A thermos of hot water will help you soften the tubing for tees. Be sure and get several straight repair couplers, you will have leaks and need to make repairs.
That being said, just a few years ago, Glen Goodrich used to pull the tubing off his forearm. He said he'd pull 5 loops, then flip the roll and pull 5 more. I never tried it, I use and have always used a spooler. I made my first spooler, then I won a spooler as a door prize at a maple conference and have used that since.
The spooler I made was simple. I cut a plywood disc about 16-18" diameter. I then drilled 4 holes to hold bolts on CPVC pipe. Those hole were on about a 3.5 or 4" circle. I also cut a smaller disc about 5-6" diameter. That had 4 holes drilled for the bolts near the outer edge and one 1/2" hole dead center for a hanger hook. The holes in both parts matched up. I then cut 4 pcs of 1/2"CPVC pipe and got 4- 1/4 x 12 bolts, 8 1/4" fender washers and 4 lock nuts. The spooler was then assembled, each bolt got a fender washer, then was slid thru a hole in the larger plywood disc. Then a 10" CPVC (1/2") was slid on, and then the smaller disc and finally a fender washer and lock nut. I repeated that 3 more times. Then I had a large hook, on a machine thread rod. That got a washer or 2 above and below the disc, then a lock nut, all mounted thru the center hole in the small disc. That hook was left loose so it could spin, the bolts with the CPVC pipe were tightened.
I used that spooler for likely 4-5 years before I won a spooler as a door prize. I later gave it to a new producer.

[minehart gap]

That being said, just a few years ago, Glen Goodrich used to pull the tubing off his forearm. He said he'd pull 5 loops, then flip the roll and pull 5 more.
I use the same method that Glenn used. I have gone up to 10 loops before flipping the roll over but only when I am working on steeper slopes and fiddling around can make me slip. It works really good.

I just never had much luck with the spoilers. I would always run out of tubing before my lateral was done then have to walk back down to connect another roll then back up to keep going. With Glenn's method, I just throw a second roll over my shoulder and start up the hill.

[Mead Maple]

I think it should be noted that deal with a 1,000' rats nest of tubing in the middle of the woods makes the heart humble. It also makes you realize that going forward, never will I ever mess up a fresh spool, I will in fact treat it like a new born that is extremely sensitive and make my life miserable should I mishandle it:lol:

After watching one of the several instructional videos on YouTube, I actually string out 3/16" on my arm until it's wanting to really twist. I could go as much as 150'-200' before this happens. Because 3/16" is so pliable, I don't have any issues with it binding/twisting and it doesn't seem to have any lasting memory. But as you guys have indicated, a spooler is probably in my future.

OP, get that 3/16" up, you won't regret it!

[DrTimPerkins]

There is a 10-15 food drop in grade. Is there any benefit to trying to do a gravity set up for 2-4 trees in a run?

A pet peeve of mine, and I've had some discussions with Tim Wilmot about this, but I really dislike the term "gravity" in this manner of use. What we are really talking about is "natural vacuum" with 3/16" tubing. Gravity sap flow has been used for 50 yrs to describe sap collection with buckets, bags, and more recently, with tubing systems that don't used pumped vacuum. Maybe "gravity vacuum" would work instead of "natural vacuum", but "gravity" alone doesn't fully describe what we're doing.

[csk91]

A pet peeve of mine, and I've had some discussions with Tim Wilmot about this, but I really dislike the term "gravity" in this manner of use. What we are really talking about is "natural vacuum" with 3/16" tubing. Gravity sap flow has been used for 50 yrs to describe sap collection with buckets, bags, and more recently, with tubing systems that don't used pumped vacuum. Maybe "gravity vacuum" would work instead of "natural vacuum", but "gravity" alone doesn't fully describe what we're doing.

I apologize for using the wrong terminology. I am just trying to suck as much juice out of these trees as humanly possible to maximize my yield/ boil time! Haha. I am going to stick with my 36” drops into buckets this year as I a tapping this week and I am not ready. New evaporator still hasn’t arrived. Next year I am going to figure out this natural vacuum thing. I got intimidated by the fitting and tools...

[Pdiamond]

csk91, you said you were intimidated by the fittings and tools, are you referring to the cost?

[csk91]

No I just don’t know exactly what I need. If money was the issue I’d pick a different hobby. Just haven’t found the right YouTube video or article with pics I guess.

[csk91]

When I go on bascom and look at the 3/16 and 5/16 fittings for a 3/16 line to 5/16 drops I can’t picture exactly what I need to buy based on the pics. I need to buy a book or see some pics of the fittings. Just a little in the dark and running up against “go time” here in coastal mass

[Sugarmaker]

You tubing should be good for many years if set up correct and maintained. I would est approx $8 per tap to set up your system. Find a local expert to help you get started. It will say you a lot of time and money too.
Regards,
Chris

[csk91]

Thank you!!!

[eustis22]

5/16 spouts to 5/16 --> 3/16 tees.

You're tapping this week? Why? I'm in Essex County and I don't start til at least Valentines.

[csk91]

I am on the water in buzzards bay. My season is over before st Patrick’s day.