Sap ladder air leaks

[blissville maples]

The last few days have been mid 30s. With the air leaks on my sap ladder as we all know any leak with the cool temps create a wind chill and freeze the leak shut( always have higher vac when near freeze bc all leaks freeze up and seal). However how do you keep the necessary air leak open for the sap ladder to remain working? Cotton ball maybe?? Been tough last few days if it freezes completely shut the sap will not lift......

[Haynes Forest Products]

I come from the old school thinking that any air leak is a bad leak. I don't subscribe to the adding a small leak in the line will increase the sap flow. SO with that said I would seal them up until further notice.

[blissville maples]

I come from the old school thinking that any air leak is a bad leak. I don't subscribe to the adding a small leak in the line will increase the sap flow. SO with that said I would seal them up until further notice.

Unfortunately if you seal them up you will get no sap flow when you run High vacuum there is no air in the system therefore a sap ladder cannot work as sap must ride up on a bubble of air, and with high vacuum there is not enough air in the system to move sap upwards. If your sap ladder Works without an air leak you have a hollow tree or air coming in somewhere you don't know about because a sap ladder will not work unless there is a pressure difference that's why most sap ladders will never run above 22 to 25 in because there has to be a air coming into it and if there's air coming into it hi Vacuum cannot be achieved

[blissville maples]

I realize it seems crazy to plug every other leak in the bush but introduce one on a sap ladder. But I didn't make the rules of physics I just have to abide by them

[n8hutch]

Have you ever tried a 3/16 sap ladder? I was told by Mike Farrell? From Cornell that a 3/16 ladder is much more efficient at moving sap but I haven't tried it yet, haven't had time.

[blissville maples]

That's interesting I would not think it would conduct enough air. Breezyhill is quite good with sap ladders from what I take and last time I was speaking with him he was saying that the half inch risers work better. He states that they thaw quicker and move a bigger air bubble which intern moves more sap per bubble I have not tried the half inch risers yet, I seem to be happy with the 5/16 however I would like to try.

[n8hutch]

I think the idea is that the sap will climb up the tubing better because of the smaller diameter of the tubing, so rather than sap pooling at the bottom of the ladder it will rise in many small drops up the ladder, of course you would need more ladders than with a 5/16 setup. If I get a chance to try one this year I'll post the results.

[Clinkis]

3/16 ladder makes a lot of sense. When you think about the physics that makes 3/16 effective it makes sense that it should work well for sap ladders. I’ve had the same problem as Bliss with my ladders. They just wouldn’t work properly without installing little leaker valves to inject a little air. Be curious to know if this would resolve this issue. Be sure nice to not have to introduce a leak into a system you spend so much time trying to keep tight.

[blissville maples]

[QUOTE=Clinkis;348078]3/16 ladder makes a lot of sense. When you think about the physics that makes 3/16 effective it makes sense that it should work well for sap ladders. I’ve had the same problem as Bliss with my ladders. They just wouldn’t work properly without installing little leaker valves to inject a little air. Be curious to know if this would resolve this issue. Be sure nice to not have to introduce a leak into a system you spend so much time trying to keep tight.[/QUOTE
Maybe I guess the weight of the sap would be less which makes an advantage. proof's in the pudding I guess. many things I would like to try as well but I will probably never have the time.... Looks like the sap just started running really nicely so going to be busy in an hour or two.......

[GeneralStark]

there is no air in the system therefore a sap ladder cannot work as sap must ride up on a bubble of air, and with high vacuum there is not enough air in the system to move sap upwards.

The trees introduce air into the system...

If your sap ladder won't work as it is frozen due to a leak, then perhaps you should try eliminating the leak. What do you have to lose? If you listened to Breezy then you used a needle valve to inject air. Try closing it.