slope: how steep is too steep

[Ryan August]

Ok, I know I need slope and understand a drop off after the last tap is good. But can u get to steep? Either on short run say seventy feet or long run two plus hunted feet.

[steve J]

If its steep and you got that much potential length I would consider running 3/16 line you would see high yield from it!

[Drew Pond Maple]

I would consider running 3/16 line you would see high yield from it!Where can you get 3/16" tubing?
Not in any catalogs

[psparr]

Call dominon and grimm derectly. $45 for a 500' roll.

[Walling's Maple Syrup]

Where can you get 3/16" tubing?
Not in any catalogsD&G makes it. It is in their new catalog. They also started making the fittings this year. They are also in the new catalog.
Neil

[maple flats]

That depends on the number of taps. If you have about 30 to maybe 75 taps, all well higher elevation than the lower end, 5/16 will work very well. If you have fewer than 30 you might well do better with 3/16. Just remember, from the lowest elevation tap to the outlet is most critical, it needs to have good drop. As long as you can get to the trees, no drop is too steep on lateral lines, that is not true of main lines, they do best at about 2% slope.
One point to keep in mind is that the 30' ideal fall is sap column. As sap flows from the tree it will contain both sap and gases, the 30' drop is the total sap column minus the air bubbles, thus it may take 40-50 or even 60' combination column to equal the ideal 30' drop. However, 30' is not required for decent vacuum, just for max. vacuum.

[steve J]

The thing to keep in mind with 3/16 is not to use any Y's to merge lines as it will act more like a dam at point were they merge. You should run a second line instead. I will try to post once things get running as to how mine performs but based on everything I have read and on the seminar class at Middlebury 2 weeks ago I have very high expectations.

[madmapler]

In conjunction with what Dave said, The key to good gravity vacuum is maintaining a column(volume) of sap in the line. Its the weight of the sap that creates vacuum. Steep slopes are excellent provided you have enough taps feeding the line to maintain the volume. The steeper the slope, the faster the sap is going to evacuate the line. You just need to keep it going. I have slopes with trees that I can only access with mountaineering gear after the freeze. I'm using mechanical vacuum though because although great results can be had with gravity, its not nearly as consistant as mechanical.