3/16" Tubing

The 2015 syrup season was a challenge from the start. We had almost 24" of snow on the ground and it was extremely difficult to tap out and collecting was even more difficult. It was at this point that I started researching tubing options because for the first two weeks of the season it took almost 2 hours a day to collect. Many years ago we had installed a 1/2" mainline on wire with 5/16" tubing. This worked well the first year but the second year was such a disaster we went back to buckets and took down all the tubing. After spending a lot of time on different forums and websites I decided on 3/16" tubing. Like anything else that you do for the first time a good plan makes things go a lot easier.

The Plan:

  • At the end of the 2016 season (still on buckets) I flagged all of the maple trees that we used along with all others in the area. There were many more maple trees further up the ridge that were never tapped due to the steep terrain that made buckets almost impossible to carry daily.

  • We then determined that we would establish two collection points within 50 feet of the access road.

  • An estimate of how much tubing and number of taps was calculated - 100 taps and 3,000 feet of tubing. Supplies were ordered and when they came in it became apparent that two things needed to be figured out: 1. how to manage the spool of tubing so it wouldn't tangle 2. How to install the fittings

  • I found plans to build a tubing spool reel but had to purchase a two handed 3/16" tubing tool (worth every penny - 3/16" tubing fittings cannot be installed without a tubing tool).

  • Install the tubing - 3/16" tubing works best when there is enough sap in the line to create the vacuum but also to not have too much that it cannot flow freely and backs up to the tap holes. Since our trees are along a brook I decide that I would not have more than 25 taps per line. Also, at the end of each line I made sure there was at least 50 feet with no taps and a downhill slope. With all this in mind we mapped out 4 lines. Three of them would come to an end at the same locations with a 10 foot drop from the last taps and the fourth had a 20 foot drop.

  • We were able to find 150 gallon open top stock tanks (food grade) from Global Industries that would be placed at the end of lines.

  • We also went with a Honda transfer pump that had the sufficient lift to go from the collection tanks to the truck.

The Installation:

  • The first line was an adventure to say the least. I had done some research and found that it is best to be in a continuous line weaving between the trees maintaining a downhill pitch. I tied off the tubing and started working my way through the trees trying to keep tension on the line the entire time. This was almost impossible to manage while holding the spool and fighting through underbrush. Instead of fighting a loosing battle I stopped and came back the next day with clippers, hand saw and a chainsaw and cleared a good walking path for all of the lines. I also made sure I had another person - one to keep tension and the other to hold the spool. This made installation much easier.

  • I found that 3/16" tubing could span a distance of about 25-30 feet beyond that it would sag no matter how tight you pulled it. This also was the point where I realized that if you pull really hard you can stretch the tubing too much reducing the diameter or even break it. At this point I realized that the span from the last tap to the collection tanks was going to need support. I ordered supplies to run 14 gauge wire. I used a lag bolt with a plastic wheel on one end and a tension ratchet on the other.

  • All four lines were in place and it was time to install the tees and drops. I had never used a tubing tool before and decided to practice a little before hand. I spent some time in my basement making the drops and installing the tees and stubby spouts. It took a little practice using the tool but after a few it went pretty quick.

Things I Learned:

  • When installing the tubing don't be too concerned about sags - when you install the drops you can tighten it up as you go.

  • Minor sags are OK further up the line but the most important part is having the last 50 feet to be tight and downhill. During the first season I had a branch come down across one of the lines bringing it to the ground and the vacuum in the line was sufficient to move the sap under the branch and back up at the same speed as normal.

  • Not all fittings are created equally. Over the past three years I have used fittings from D&G, Leader and CDL. Without a doubt the CDL fittings are of higher quality and are much easier to work with. The others had burs on the ends of the barbs making it difficult to install in the tubing or were weak and would bend before being inserted.

  • The first year I used 3/16" drops but have changed to 5/16" because on days of heavy runs it allowed for the sap to have room and flow into the line easier and not back up.

  • I have switched from using stubby spouts and adapters to clear check valves. Having one fitting instead of two reduces micro leaks. I am not sure check valves are necessary and in the future will try standard clear seasonal spouts.

2021 - will not use check valve spouts this year! Last year had about 10% fail - the ball inside the spout became stuck and would not move in and out. Some were stuck in and others out. Will be using a clear season spout.

  • Drops and spouts need to be changed out each year. This became clear during the 2018 season when I changed out drops and spouts on two lines and only spouts on the other two. The lines with new drops ran for two weeks longer.

  • If installing vacuum gauges make sure they are above the highest point of the line and the fittings are tight otherwise sap will push right up into the gauge.

  • When a line breaks or something gnaws its way into it replace the entire section between the fittings. Do not use a union - this will add another point of restriction. If you are by yourself use two tie downs to make this easier. Wrap the tie down around the tubing and the tree at either end of the break and ratchet it down tight. This will prevent the entire line on either end from loosing tension.

  • Make sure your tap holes are clear of shavings so they will not get sucked into the tubing and get stuck in the fittings.

  • Walk your lines as often as possible checking for leaks or branches leaning on the lines. Carry a roll of electrical tape with you. It can be wrapped tightly over minor leaks for a temporary fix and allow you to quickly find them when you have time to fix properly.

  • Look at the sap at the end of the line to see how it flowing. A line that has no leaks will have some bubbles but will flow freely and consistent. If there is a leak somewhere in the line you will see smaller bubbles and an inconsistent flow.

  • When walking the lines looking for leaks there are three things: 1. A stream of bubbles entering the line 2. You can sometimes hear a high pitched whistle 3. Sap going the wrong way - uphill.

  • If you have a location that is constantly having squirrels chew into the lines or drops you can wrap the tubing with Gorilla Tape. Not sure if it is they cannot chew through it or if they don't like the smell but either way it works.

  • To save some time this year I decided to install my drops in December instead of when tapping out. The problem was how to attached them to the fitting or tubing. By using 5/16" drops the tubing doesn't secure back into the tees. I didn't want them to just hang down so I found tubing rings from Lapierre that I ordered from Bascom's Maple. When it is time to tap out I will just cut off the ring and install the tap. This will allow me to install drops anytime during the year.