The Poorer Man's Diaphragm Pump Vacuum System

[Cedar Eater]

We started using these ebay cheapies last year, still running strong this year. The pumps are all 4L/m and draw about 1.1 amps an hr, which if I understand it right, a 12amh battery should last10 - 11 hours. These pumps will generate more sap at a cheap cost.

I have mostly reds, so I'm counting on vacuum to keep them flowing when they would otherwise be finicky. I have a cluster of three trees with a total of four stems with one of the trees being a double or triple tapper that I want to put one of these rigs on. The trees are in full sun and sit in a creek bed so they have crowns that would make the queen of England blush. I should get a pic of them.

Anyway, the pumps won't draw full Amps the whole time, so I think your estimate on the run time of the batteries is conservative. They have to be pushing against full backpressure to draw full Amps. I anticipate significantly longer run times, especially if the pumps are shut down during freezes using the cheap temperature controllers I also got from Amazon but haven't figured out how to protect from weather yet. I will probably just throw a ziploc bag over them and staple it to a backboard. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

This is fun.

[littleTapper]

That little controller will work great. Calibrate the temp first. Mine was off a few degrees, but with calibration it's working perfectly for my Shurflo 4008 setup.

[Cedar Eater]

That little controller will work great. Calibrate the temp first. Mine was off a few degrees, but with calibration it's working perfectly for my Shurflo 4008 setup.

Good point, but it came without instructions and I don't see any way to calibrate it. I was going to just determine its bias by setting the probe in slushy water to see what it reads and adjusting my setting accordingly.

[littleTapper]

Instructions:

http://usefulldata.com/cheap-12v-tem...-probe-review/

[Cedar Eater]

Thank you very much for that link!

[wmick]

Thanks for the explanation, Cedar Eater... Makes perfect sense...
I have another question though... I'm thinking about a way to allow the sap to bypass the pump and work on natural gravity/vacuum, in a case where the battery goes dead or pump quits... Do you think your "bypass" line would accommodate enough volume for this on 40 or 50 taps? I was also thinking maybe about some sort of 2nd bypass line with a weak check-valve in it.. (that the pump would pull closed under vacuum, but it could fall open if vacuum disappears.
Any ideas??

PS - another thought... Will the trees not draw your sap back though your bypass... if you are not there to disconnect things when the temp starts going down each evening??....

[Cedar Eater]

Thanks for the explanation, Cedar Eater... Makes perfect sense...
I have another question though... I'm thinking about a way to allow the sap to bypass the pump and work on natural gravity/vacuum, in a case where the battery goes dead or pump quits... Do you think your "bypass" line would accommodate enough volume for this on 40 or 50 taps? I was also thinking maybe about some sort of 2nd bypass line with a weak check-valve in it.. (that the pump would pull closed under vacuum, but it could fall open if vacuum disappears.
Any ideas??

PS - another thought... Will the trees not draw your sap back though your bypass... if you are not there to disconnect things when the temp starts going down each evening??....

There's a very smart controller that Biz will be marketing called the Super Sap Sucker that opens a valve to allow gravity flow when the pump gets shut off due to cold or low battery. I don't think the bypass will accommodate much flow with natural gravity. I would not turn the pump off until the temps drop to at least -1^oC. By that time, the frozen tubing should be preventing either natural gravity flow or reverse flow. Keep in mind that the goal here is a cheap system for fewer taps and lower amounts of flow than you would put through a Shurflo 2088 or 4008. You won't lose much if you lose the whole system and you won't lose much sap if you're not running when you would want to be.

[sugarsand]

We also use a bypass by placing a tee in the inline with a piece of 3/16 long enough to reach the bottom of the tank. Below the tee is a cheap little plastic valve that I found on ebay. By opening the valve full, with pump shut off, I get full bypass. You can adjust the valve to get the best performance from your pump.
Hospitals recieve things in thick styrofoam coolers that are usually thrown out, they work great to house the pump and battery against cold and rain.

[wmick]

Well Cedar Eater - You convinced me... Got a late start this year... A Fresh built rig that hasn't boiled a drop yet.... Waiting for the weather to turn and worried that it will be a very short stint of sap ... Figured I could use a little edge. (vacuum)
Gave my credit card number to Amazon and Voila.... should have the goodies by the weekend, to build your system... We can compare notes..
BTW - How many taps, max, on 3/16" would you attempt with a setup like this..
Thanks for the inspiration.

[Cedar Eater]

Well Cedar Eater - You convinced me... Got a late start this year... A Fresh built rig that hasn't boiled a drop yet.... Waiting for the weather to turn and worried that it will be a very short stint of sap ... Figured I could use a little edge. (vacuum)
Gave my credit card number to Amazon and Voila.... should have the goodies by the weekend, to build your system... We can compare notes..
BTW - How many taps, max, on 3/16" would you attempt with a setup like this..
Thanks for the inspiration.

I'm new at the mechanical vacuum game so I'm trying the more conventional Shurflo 4008 next year on about 50 taps (two lines of approximately 25 taps each) and the significantly cheaper version this year on 30 taps max. I chose the 25 tap number because some people have claimed that 25 is the ideal number for 3/16 on mechanical vac. But having said that, any vacuum is good vacuum so the right number might be dependent on how well vacuum can be transmitted down the line. If I reach a point where I can disconnect the far end tap and the line doesn't get sucked out immediately, I'll know that I've gone too far.