3/16 into 5/16

[tonka]

I did some looking and found a little bit of info but would like to hear from more of you guys who have tried running 3/16 for the top half of a run and 5/16 on the bottom half of a run. My current setup in one woods I lease I installed all 3/16 tubing running into a 1 1/2" mainline. From my mainline to the top of the line has maybe 20 to 25 ft drop in elevation with an average of 22 -25 taps per line. I realize NOW that it was not beneficial to the lower taps because the taps do not have the drop in elevation that is required to be able to form some sort of vacuum. With seeing only a 5.09 gallon per tap of sap yield this season it really opened my eyes on how my current setup didn't work for me, so instead of buying a bunch of 5/16 to replace the 1,000 taps, I would like to know how well it would work if i have the 3/16 on the top half (200-300ft 12 taps average) and run the bottom half (200-300ft 12 tap average) with 5/16 on the bottom half running into the mainline? Thanks in advance!

[bj's sugaring]

Can you move your mainline further downhill, and extend your 3/16" lines with more 3/16" to achieve vacuum at the lowest trees? That would work for you.

[tonka]

I wish I could, I have my mainline at the lowest part of the woods.

[DrTimPerkins]

What is the drop on the upper half vs the lower half? Is any of it relatively flat?

[tonka]

Top half has about 15ft of drop with the bottom half having about 5 to 10 ft of drop. As the mainline runs further into the woods up the lowest part of the hill it gets less to about 10 ft of elevation difference.

[n8hutch]

I'm not sure but it sounds like you are thinking about replacing the last 200-300 ft closet to the mainline with 5/16 and hooking the 3/16 into the end of the 5/16 lines? Is that your plan?

My thought would be to run new laterals with new saddles for the lower trees and keep your 3/16 lines running all the way to the mainline, just put a repair connector in where your drops used to be ,and or reroute the lines slightly, that would be your best bet.

Do you have vacuum on the mainline? Most likely you could add vacuum and you wouldn't have to do anything to your 3/16 lines.

Even a guzzler pump would do wonders, alot of people in these parts made almost zero syrup this year w/o a vacuum pump.

[tonka]

Yes n8hutch, keeping the top half in 3/16 and switch out the bottom half to 5/16 connected to mainline. I would like to install vacuum and leave it be but that's not an option at the moment since the bush is 12 miles one way, leased ground, and if I were to run vacuum there I would want it to be electric and not a gas engine just so it's less I have to do with it during season, no gassing the engine daily and what not.

[mol1jb]

You could do a 12v shurflo pump to a car battery and just switch out to recharge.

[Super Sapper]

By replacing the bottom half with 5/16 you will reduce your vacuum on your upper half. Will this be less sap than the gain on the lower half? If you are only doing 22-25 taps per line I do not feel you are losing much in frictional losses on your lower half. If anything run new lines with 3/16 on top but run more diagonally so you get your 25 taps and then down to the mainline. Run separate 5/16 for the bottom lines.

[tonka]

I think I'm hurting my self because of how close to the main line my first taps are. They rang from just a few feet to 30maybe even 40 feet away from my mInline and I'm not getting any to very little elevation drop from my bottom tap to the mainline. If I can get vacuum readings off the 3/16, great, but I obviously did not see that this year when I my average gpt was slightly above 5 gallons of sap. In my smallest woods of 200 that is hooked up to machanical vacuum pulling 20-22 inches I averaged 14.5 gallons of sap per tap, yes it was on machanical vacuum but I thinking if the 3/16 was working decent to good, i should have done better than 5 gpt. If I switch out even the bottom 200' with 5/16 I think it will help with the lack of elevation drop that is needed more for 3/16 vs 5/16(from my understanding) plus I will still get some vacuum readings on most of the 3/16 because it will still have that column of sap in the line and when the 5/16 line is full it should help with creating vacuum in the higher 3/16 line on top of the hill. This is the conclusion that I've come up with. Either way, 5/16 or 3/16, natural vacuum will occur, just depends on how many inches you'll be pulling and how long it takes each day for the vacuum to occure.

[DrTimPerkins]

If the lower section is flat, switching over to 5/16" tubing would help. With only 20 ft of drop, you're only going to get 15-18" Hg AT THE TOP at best. Lower down on the slope you're getting proportionally less (at best). Did you ever check the vacuum level at the top of the lines or observe the flow in the lines? That would tell you whether you actually had any natural vacuum, or you needed to spend more time looking for leaks. Even very small leaks on a 3/16" system will result in little vacuum being generated. It needs to be VERY tight. Another possibility is that you had wood chips plugging up the tees and connectors. You'd be able to see that just by watching the liquid in the lines for a bit while the sap was running.

As someone suggested, maybe separate some lines with the trees on the top on 3/16" and those on the lower slope with 5/16".

[tonka]

While tapping I did find several damaged spots that I did fix and towards the end of the season and while pulling taps I did find a couple very small leaks in 2 lines that I missed. From what I could tell of during season it seemed to be working since I could see the occasional bubbles flowing down several lines. I'll admit that I should have walked around more but seeing a steady stream flowing out into my tank made me think things are working quite well until the end of the season when adding up all the gallons of sap per woods and breaking it down to tap average. I'm wishing I would have had a couple gauges on top to see if any vacuum was being produced. Another thing that has crossed my mind was during season several nights got in the mid to upper teens and with it being a north facing slope, that might have played a little part in the yields too. I'm kind of likening the idea of running 5/16 on the bottom and keeping the top on 3/16, see how that will perform next season. Thanks again to all who have put in their 2 cents, and if there are anymore advise please do share!a