Ok to allow sap to suck back into trees?

[mhmaple]

Hopefully I didn't miss an obvious answer to this on the forum, and forgive me for asking - I'm a newbie: I've heard that with a tubing system, leaving the end of the main line in the bulk collection tank overnight can lead to a reverse flow phenomenon where the sap travels back up into the trees from the tank.

My question is, if I'm not able to boil for several days, can I use this to my advantage by intentionally leaving the end of the main line at the bottom of the bulk tank, then a day or two before I want to boil, raise the end of the main line to the top of the tank so the sap then stays in the tank (ie to prevent siphoning)?

I figure if this works, I'd be able to tap lots of trees so I'd have plenty of sap on hand on days when I can boil, but at the same time I could avoid wasting sap (and unnecessarily stressing the trees) by letting the trees pick the sap back up at night during stretches when I can't boil for a few days.

Only problem I see is infecting the trees with bacteria, since no line or tank is perfectly sterile. Is that a real issue?

Thanks for any advice/opinions out there.

[Pete33Vt]

I have never heard of trees sucking sap back up the lines. The only thing you would have if you left your line in the tank for a few days is a overflowing tank. Hope this helps.

[gator330]

Keep the end of the line out of the sap!!!!!!!!

If you need to wait to boil then it will wait. There are a lot uf use that hold sap for 5 days till the weekend to boil. Just keep the sap cold may come a little darker but it's still good.

As for stressing the tree if you tape by the chart one or two even three, if a real big tree, your not going to stress or hurt the tree by taking a small % of sap from it.

[Thompson's Tree Farm]

Avoid having the sap suck back into the tap at all costs. It will carry bacteria and it will contribute to the sap flow stopping earlier in the season.

[Russell Lampron]

Just touched on this topic yesterday at The NH Maple Producers Assn meeting. The topic was actually refering to microbes, which cause the tap hole to close, getting sucked back up into the tree when you shut your vacuum pump off. Proctor Research Center and Leader are working on a spout that will prevent this from happening.

Gravity systems don't have as much of a problem with this if you use drops that are long enough. As the tree sucks up moisture from the roots it will suck sap and microbes back into the tap hole.

My advise: Keep the pipe above the sap and use drops that are 30" long.

[Dennis H.]

Russ I also heard about the tap system they are working on. It is to be some kind of one way check valve. The only problem that they are working on is how to clean the tubing system.

Sucking sap up into trees? they say it can happen. When I attended the NY Conf in Jan there was a class that talked about using new drop lines every year just becasue of that. When they did a test they found that a tree could suck sap up about 1 foot of tubing. That is why they are saying to replace both spile and drop line, not just the spile.

[mapleman3]

that means you can re-make drop lines at about 200 drops per roll of tubing, at 30" per drop, at around 50-55 bucks a roll , thats appx $3.60 per drop + the price of a tap.... gets mighty expensive!!

maybe every 2-3 years but every year?? I can't afford that.

[3% Solution]

mapleman3,
You think that is expensive, check this out ...............
If you want to get 100% from your bush each and every year......... replace everything ............. every year!!!!!!!
Studies at Proctor have shown this to be true!!

Hey, hey, are you alright??
You look kinda faint, you going to be ok????

Dave

[mapleman3]

an you imagine??? if you have 1000 taps and changing it EVERY YEAR!!!

there is a breaking point to what we do, my thought is you do the best you can do, clean and fix lines.. maybe change things every 5-8 years (that may be pushing it too)

on the subject
I'm on Gravity on my big bush, I will do as normal, and I don't see a way for the sap to suck out of my tank, theres no way a tree/trees will suck a tank of sap back uphill... I wouldn't worry too much about that!!

[gator330]

Makes sence, That is also why buckets make the most sap. If you don't spill it!!! Cheaper to, just more laber intensive.

[gator330]

that means you can re-make drop lines at about 200 drops per roll of tubing, at 30" per drop, at around 50-55 bucks a roll , thats appx $3.60 per drop + the price of a tap.... gets mighty expensive!!

maybe every 2-3 years but every year?? I can't afford that.

If you do the math that way, Why is it you can buy pre-made 30" drop spout and tee for 1.60???

[Clan Delaney]

mapleman3,
You think that is expensive, check this out ...............
If you want to get 100% from your bush each and every year......... replace everything ............. every year!!!!!!!
Studies at Proctor have shown this to be true!!

Hey, hey, are you alright??
You look kinda faint, you going to be ok????

Dave

Sure, but where's the cost/benefit balance? If replacing everything every year means that your bush puts out just enough extra sap to cover the costs of all that new equipment, you're still having the take the time to replace it every year, just to break even. Yikes.

[3% Solution]

Clan,
Pretty much a "no brainer" for all maple folks.
It was just one of those experiments they do there.
Interesting info.
Another interesting fact was that you can drill 100 holes in a tapable tree and not kill it!
However, if you keep doing it year after year, it's not going to help the tree much.
Ok, off subject, let's get back to the subject >>>>>>>>>>>>>>>

Dave

[gator330]

Sence off the subject a bit more won't hurt. Do the 100 taps on a cule tree. See how much sap you get, just to see. Give the tree time to heal up and cule it then. How COOL would the boards look from that tree!!!

[Dennis H.]

I will have to look up the guys name who gave the class at the Conf in NY but what they did was run a double tubing system and put a tap from each tubing system into each tree about 6" apart.
One tubing system was all brand new tubing and the other was new but they put in old drop lines. What they came up with was that at the start of the season they were produceing about the same but as the seaon went on, about 4 weeks in, the one with the new drop line was producing, get this, a 100% more than the the one with the old drop line.

He said that when you are capable of producing that much more with new drop line that it would pay for it self.

Which that then led into the situation when the tree sucks sap back up into itself. That tested that by taking the drop line and looping it down below the lateral. It caused a dead spot in the drop line.

It gets even weirder with a gravity set up. he forund that whe the tubing is running full the tres at the bottom of the main the sap was being pushed back into the trees by the column of sap above them on the tubing system.

Now that is a whole different Thread.

[sapman]

that means you can re-make drop lines at about 200 drops per roll of tubing, at 30" per drop, at around 50-55 bucks a roll , thats appx $3.60 per drop + the price of a tap.... gets mighty expensive!!

maybe every 2-3 years but every year?? I can't afford that.
Seems to me that the tubing cost is actually $.36 for a 30" drop, isn't it?

And from what I've heard, a lot of big producers aren't even washing tubing anymore, and not really suffering for it. After all, with vaccuum, there shouldn't be much left in the system at the end if you're careful.

Tim

[jason grossman]

what you need to know is that trees do "suck" some sap back in the tap hole. when you tap a tree and add vacuum you are creating a negative pressure outside the tree (that is higher inside in pressure) thus causing sap to flow. when you shut off your vacuum the pressure in your lines equalizes with the barometric pressure, then when the pressure inside the tree changes and becomes lower than that in the tubing it can pull some liquid back into the tissues. this also pulls in microbes that have been growing in the drops, which causes the hole to close faster. the trees don't pull alot back in probably only up to two inches from the hole. so leave your vac on until everything freezes up in the drops. also avoid tapping below the laterals and try to avoid curls in your drops that hold sap.

[brookledge]

I hope they come out with a spout witha check valve. I use vacuum to clean my lines so washing isn't a problem. As far as I'm concerned the only way sap can get back to the tap is when you shut the vac pump off early. The tree is under vacuum so it can pull backwards. I think the key to this is to have check valves on the mainlines. I know when I shut my vac pump off my vac tanks will hold vacuum for along time. Some other producers that I have seen as soon as they shut the vac off air goes shooting back up the mainlines. One of my bushes I have a zero tank and a check valve at the pump. so I know I'm not getting a rush of sap and air back.
Keith

[Haynes Forest Products]

How long does it take for bacteria grow and cause trouble in the tap hole. In Door County Wisc the season is so short 11 days last year isnt alot of time.

[jason grossman]

haynes, once you drill the hole bacteria will start to grow! once the sap is exposed to the atmosphere and temps allow it will grow. all we can do is manage it as best as possible. as some may remember the days of pills in the tap hole keep sap flowing by killing everything, but not real good for people!!

[maple flats]

The class Dennis H. is talking about was given by Steve Childs, Cornell maple Specialist. He did say that tubing can allow some sap/bacteria/micro Organisims to enter the tree. He said that it is not practical to change drops every season but is conducting tests to determine a guideline. He suggested it might end up being 5 years but does not have any guide lines yet. He was doing double tubing experiments with 2 tubing systems on each test tree and a collection vestle for each at each tree. He said his tests were being done with both taps being on the same side of the tree and on gravity only because of the complications of having a vacuum system with individual collection at each tree. He said he hopes to have a guideline within a year or two. He was counting the cost of materials and labor and comparing that against the increased sap flow before making a recommendation.

[WESTVIRGINIAMAPLER]

I bought 250 of the Leader tree saver spout extensions this year to give them a try. I am going to try them in 2 different south bushes with the majority of the taps in both bushes on them and aprox 65 in one bush not on them and aprox 15 in the other bush that are on a line by themselves so I can see if they make much of a difference. Only $ 37.50 for them, so if they produce an extra gallon of syrup, they have more than paid for themselves.

[Dennis H.]

Thanks Maple Flats, That is who I was trying to remember. Steve Childs.

[Russell Lampron]

An ongoing experiment that Proctor is doing right now is comparing the sap flow from 4 tubing systems. Each system has 200 taps and were installed by 3 of the manufactures and the forth by Glenn Goodrich.

The first system, installed by Leader, is the system where new tubing is installed every season.

The second system, installed by Dominion & Grimm, has had just the spout replaced for the first 3 seasons but because of similar results with system 3 they are going to replace the drop for this season forward until the end of the test.

The third system, installed by CDL/IPL uses the 2 piece spout and adapter and they are replacing just the spout adapter every year.

The forth system, installed by Glenn Goodrich is only washed with water and compressed air at the end of the season. Glen was chosen as the independent installer because he uses what he likes best from all 3 of the other installers companies.

The results so far using the first system as the control show that the sap flow percentage from systems 2 and 3 were pretty much the same but only about 83% to 85% the volume of system 1 after the second year. The system that was only washed was around 82%.

The third year, which was last season, systems 2 and 3 were again very close to each other but slightly higher than the year before. The sap was around 87% to 88% of what system 1 was. The forth system which was washed only declined again to about 78% after just 3 seasons.

The test is showing so far that there is some benefit to replacing the adapter or the tap each year but isn't showing what the benefit is to washing your tubing as compared to doing nothing at all. Why does this post belong in this thread? The declining sap flow amounts from the systems that aren't replaced every year are caused by micro organisims in the tubing getting back into the tap hole!

[Homestead Maple]

At the NHMPA meeting yesterday, Tim Perkins from Proctor Research said that Proctor is going to set up a bush this summer where they are going to run just main line to the trees and have just 5 taps per line, just to see what kind of sap yields they get. He didn't say if this would be 1/2" or larger main line.

[Russell Lampron]

Bill,

I believe he said that they were going to run mainlines everywhere and put just one tap per lateral.

[Homestead Maple]

Hi Russ,
I see, 5/16 laterals off the main lines and 1 tap per lateral.
Well........ that might be less expensive to replace each year but expensive to set up at first, huh?

[Gary R]

Russ, Thank you for the interesting data on tubing. Heck I don't even have any tubing. It would have been interesting if they could have done system 5. Tubing rinsed with a sanitizing agent and rinsed before taping. We should know that water alone won't kill bacteria. It appears that the closer the bacteria is to the hole at the time of tapping, the lower yield due to tap hole closure.

Thanks again!

[ennismaple]

I hope they come out with a spout witha check valve. I use vacuum to clean my lines so washing isn't a problem.

Keith

While I was talking to him on Saturday Bruce Gillilan from Leader mentioned that they were looking at putting the check valve in the disposable spout extension for the producers who pump water through their lines. I'm pretty sure he also mentioned they were developing a spout with the same check valve which would work fine for people who vacuum wash their lines.

[Homestead Maple]

If it's recommended that there should only be 5 or so taps on a 5/16ths lateral, I wonder if manufacturers will ever go to say a 3/8ths or a 7/16ths size line for laterals? More sap carrying capacity and maybe you could put 20 - 30 taps on a lateral.

[brookledge]

I won't say it won't ever happen but I feel it won't because of all of the tooling needed to make it and then all of the different types of tees, Ys, etc. would be very costly
Keith

[Smitty]

At the end of a sap run (when the trees shut down for the day) a small amount
of sap is sucked back into the tap hole(on a non-vaccum system).Thus making it important to have a minimal drop line of 20" or so,if the sap in the line gets back in the tap hole, it will greatly shorten your sesaon. Which is another great reason to replace taps every year and drop lines every 3-5 years.
I hope this helps.