CV Spouts - Still Preferred?

[cray54]

Is there any current published research showing non check-valve spouts performing better than check valve spouts and if so, under what circumstances?

We're having a discussion about whether to continue using CV spouts, but I don't see anything suggesting anything other than CV spouts.

[We have been using Check Valve Spouts for many years. We try to remain aware of current research to make sure our methods are keeping up with current knowledge. I have been hearing people talk about other spout options performing better than CV Spouts, but I can't seem to find any published research showing it.]

Thank you, Chris

[wvfdc4]

Interested too, currently running the CV's and will for this upcoming season. Very interested in the new UVM curved spouts though from a production cost as well as spout cost.

[DrTimPerkins]

I have been hearing people talk about other spout options performing better than CV Spouts, but I can't seem to find any published research showing it.]

You can’t find what doesn’t exist. The last research comparing CV spouts to regular spouts was by Dr Mike Rechlin (WV) a few yrs ago and published in The Maple News. This was with 3/16” tubing. Same results as almost every other scientific study done by Cornell or UVM. CV is almost always better than anything except complete replacement of spout and dropline, but over a 3-yr replacement schedule of drops, the CV typically comes out ahead of replacement economically. The only other comparable approach is bleach, but that is costly in terms of labor, plus squirrel issues and having to either rinse or let first sap run on the ground.

[cray54]

You can’t find what doesn’t exist...

That is encouraging, I thought I might be missing something!

Within the CV lineup, has there been any comparison between Check Valve Spouts and Check Valve Adapters w/ Stubby Spouts?

Thank you, Chris

[DrTimPerkins]

Within the CV lineup, has there been any comparison between Check Valve Spouts and Check Valve Adapters w/ Stubby Spouts?

Results are almost identical. Extremely small "stubby" effect, but not enough to produce a noticeable or significant different in yield. Preference is typically the biggest determining factor. Some people like the stubby/adapter system, others like to replace the entire spout.

[cray54]

Results are almost identical... Preference is typically the biggest determining factor. Some people like the stubby/adapter system, others like to replace the entire spout.

It occurs to me that there may be significantly more labor involved with complete spouts - possibly needing to be pressed on with a tool, whereas the adapters can be installed easily while tapping. Are the spouts for 5/16 and 3/16 line usually requiring a tool to install, or are they designed to be pressed on while tapping?

Thank you, Chris

[Amber Gold]

I used to use the stubby w/ CV adapter system, but then I switched to seasonal's CV's.

I do find that tapping in, and pulling taps, does take a bit longer with the seasonal's. It only takes a second to seat the adapter on the stubby and then hit it into the tree which locks them together. Seasonals require a tool to get it onto the spout

[cray54]

...It only takes a second to seat the adapter on the stubby and then hit it into the tree which locks them together...

That is interesting, we always avoided hitting the stubby. We would hammer the adapter in first, and then do a 1/4 turn press to seat the stubby.


...Seasonals require a tool to get it onto the spout

Thank you for letting me know. I decided to get just a few and try them out. I don't like the idea of needing a tool (especially when we usually have more tappers than tools), but I figure it is worth trying. If a tool wasn't needed, I think we would switch over completely right away.

[cray54]

Results are almost identical...

With this in mind, I picked up a mix this year to try them out.

Is there any guidance for how far before tapping the spouts can be installed on drops and left hanging (It looks like it would have to be a separate operation for us)?

[Andy VT]

This thread makes me curious the status of those barbed spouts.
Last I knew they were in trial.
Anything on general market yet? And will they be CV, non, or available both ways? And from who?
I recognize it might be too early for these questions.
Just curious. (Won't apply to me anytime soon with my drops to buckets)
Andy

[DrTimPerkins]

Is there any guidance for how far before tapping the spouts can be installed on drops and left hanging (It looks like it would have to be a separate operation for us)?

We've had a few papers on that in the past couple of years. You can put the spouts out anytime after the temperatures fall to freezing. Leaving drops dangling open or plugging them makes no difference either.

[DrTimPerkins]

This thread makes me curious the status of those barbed spouts.
Last I knew they were in trial.
Anything on general market yet? And will they be CV, non, or available both ways? And from who?
I recognize it might be too early for these questions.
Just curious. (Won't apply to me anytime soon with my drops to buckets)
Andy

We've had several papers on this in the past year. This discusses the 5-yr development of the spout https://mapleresearch.org/pub/innovations-in-maple-sap-collection-systems-spouts/ The latest one with the 2023 results of the commercial spout is https://www.themaplenews.com/story/proctor-reports-on-2023-season-barb-spout-results/473/ Another one coming out in next issue of The Maple News.

In general the Arc-Barb spout produces about 10-25% more than a regular spout depending upon the type of season (lots of factors). Ray Gingerich (Ohio) was one of our cooperators who tested them last season (2023). He found a 36% improvement comparing two side-by-side bushes with 500 taps each (Arc-Barb Spout vs normal spout). Unsurprisingly, he was the first one to place an order this year. :lol: Testing at UVM PMRC in 2023 found a 10.3% and 12.2% increase in sap yield (two different studies) with the commercially produced molded spout (as opposed to our machine spouts we tested in prior years).

The Arc-Barb spout and other fittings are being produced and sold by Middle Valley Maple https://www.middlevalleymaple.com There are more things in the development pipeline that hopefully will be coming out in the next few years.

The CV is licensed to H2O/Leader. The two companies would have to agree to work together to make an Arc-Barb CV Spout. I have no idea if that will happen (I stay away from the business side of things), but I've heard the question quite a bit.

[SeanD]

Are those results with the Arc spout and tee together or does just using the spout result in those increases?

[buckeye gold]

Are there any plans to make the arc-barbed spout and other arc fittings in 3/16" or are they only for 5/16"

[johnallin]

We've had several papers on this in the past year. This discusses the 5-yr development of the spout https://mapleresearch.org/pub/innovations-in-maple-sap-collection-systems-spouts/ The latest one with the 2023 results of the commercial spout is https://www.themaplenews.com/story/proctor-reports-on-2023-season-barb-spout-results/473/ Another one coming out in next issue of The Maple News.

In general the Arc-Barb spout produces about 10-25% more than a regular spout depending upon the type of season (lots of factors). Ray Gingerich (Ohio) was one of our cooperators who tested them last season (2023). He found a 36% improvement comparing two side-by-side bushes with 500 taps each (Arc-Barb Spout vs normal spout). Unsurprisingly, he was the first one to place an order this year. :lol: Testing at UVM PMRC in 2023 found a 10.3% and 12.2% increase in sap yield (two different studies) with the commercially produced molded spout (as opposed to our machine spouts we tested in prior years).

The Arc-Barb spout and other fittings are being produced and sold by Middle Valley Maple https://www.middlevalleymaple.com There are more things in the development pipeline that hopefully will be coming out in the next few years.

The CV is licensed to H2O/Leader. The two companies would have to agree to work together to make an Arc-Barb CV Spout. I have no idea if that will happen (I stay away from the business side of things), but I've heard the question quite a bit.

Hello Dr Tim..

I like idea behind these. Can I use my current tubing tools, spout puller?

Thanks.

[tcross]

has there been any studies, or do you foresee any that would compare it to the cv spout? the price point seems pretty reasonable!

[DrTimPerkins]

Can I use my current tubing tools, spout puller? .

Yup. https://m.youtube.com/watch?v=TQIACHdXb_A

[DrTimPerkins]

Are there any plans to make the arc-barbed spout and other arc fittings in 3/16" or are they only for 5/16"

Yes. 5/16” spouts first. 1/4” spouts and spouts with 3/16” tubing connectors in the works, among other things.

[DrTimPerkins]

has there been any studies, or do you foresee any that would compare it to the cv spout? the price point seems pretty reasonable!

None planned for 2024 at UVM PMRC. Can’t say beyond that because I WILL be (re-) retired by that time.

[Amber Gold]

It sounds like the CV and barbed spouts have comparable sap production increases, but the barbed spouts are ~50% the cost.

It is surprising that the increase in daily flow because of the shallower spout depth of the barbed spouts is comparable to the late season sap flow increase benefit of the CV spout. Thinking about that some more, you'd be getting more sap when the sap quality is higher, and less sap when the sap quality is lower...seems like a good thing now that I'm thinking about it.

The ultimate spout would be a barbed, CV spout...

[DrTimPerkins]

The ultimate spout would be a barbed, CV spout...

Whether or not we ever see that is impossible to say.

[Andy VT]

I'm glad I asked about the barbed spouts. This is fascinating how barbed and CV are now in competition with each other.
I don't use CV because I feel the benefits aren't big enough for drops into buckets for my little operation, and I like using stainless steel to keep just a little more plastic out of the landfills.
After this thread I had to give barbs a quick thought... but, alas, no, I'll skip those too. The trees I tap are all urban yard trees... any unnecessary tear out on removal is a no-go.

But if I had a real operation... I'd be giving barbs a hard look after this thread. And if I were H2O I'd be making some phone calls....

[johnallin]

Yup. https://m.youtube.com/watch?v=TQIACHdXb_A

Thanks...thought you were retired and off to Michigan.

[DrTimPerkins]

Thanks...thought you were retired and off to Michigan.

So did I. :lol:

Shortly after I retired Dr. Abby decided to step away. We had several ongoing projects that she was going to finish up. One was 9.5 yrs into a 10 yr study. Another was 5.5 yrs into a 6 yr study. I couldn't let those go unfinished, so accepted a 10 month appointment with UVM working remotely (from Michigan) with no administrative, supervisory, or budgetary duties. Just the research (the fun part). I am NOT the Director (they split the position into two positions and a search is ongoing).

I am involved in research for the 2024 season, most of which will focus on finishing up those last couple of studies, but also several trials of the Arc-Barb Spout.

[johnallin]

So did I. :lol:

Shortly after I retired Dr. Abby decided to step away. We had several ongoing projects that she was going to finish up. One was 9.5 yrs into a 10 yr study. Another was 5.5 yrs into a 6 yr study. I couldn't let those go unfinished, so accepted a 10 month appointment with UVM working remotely (from Michigan) with no administrative, supervisory, or budgetary duties. Just the research (the fun part). I am NOT the Director (they split the position into two positions and a search is ongoing).

I am involved in research for the 2024 season, most of which will focus on finishing up those last couple of studies, but also several trials of the Arc-Barb Spout.

Glad to hear you're still around to straighten out some of the "off the wall" advice that can show up here...IE: clear press knocks from Fred... and that you're doing something you enjoy.

Now that we've got clear presses and clear barbed spouts - how about clear 3/16 "T" Fittings so you know when they're plugged? You can do it!

[DrTimPerkins]

...how about clear 3/16 "T" Fittings so you know when they're plugged? You can do it!

We've got better ideas on how to solve that particular problem (clogging of fittings)...and ways to address other issues. Stay tuned....

[Andy VT]

So did I. :lol:

I am NOT the Director (they split the position into two positions and a search is ongoing).



Wow! The pool of maple doctors has to be small. Back in my single days one of my housemates gave me an honorary doctorate in pancake-ology, but in maple syrup I'm more of a GED in progress. Glad you're able to help tie up some loose ends!

[johnallin]

We've got better ideas on how to solve that particular problem (clogging of fittings)...and ways to address other issues. Stay tuned....

I most certainly will, but you’ve got to keep working on it though :lol:
Non of this retired stuff! Next you’ll be telling us your the “Michigan PickleBall Champion!”
<Big grin>

[82cabby]

So, I’ve gotten myself confused a bit. For a small 100-200 tap gravity operation on 5/16 tubing… which might produce more in a season, the arch-barb or the check valve spouts? I’m guessing the check valve for gravity and the arch more for vacuum but the barb with the shorter penetration has me second guessing….

Recently we’ve been using the disposable clear plastic and been using new spouts every year with decent results but always looking to optimize!

[littleTapper]

Totally unscientifically proven, but on my silver maples I use a 19/64" drill bit with CVs. They don't seat as deep and seal just as well as using a 5/16" bit. Not sure what it does for my yields, but seems better....maybe :)

[littleTapper]

So, I’ve gotten myself confused a bit. For a small 100-200 tap gravity operation on 5/16 tubing… which might produce more in a season, the arch-barb or the check valve spouts? I’m guessing the check valve for gravity and the arch more for vacuum but the barb with the shorter penetration has me second guessing….

Recently we’ve been using the disposable clear plastic and been using new spouts every year with decent results but always looking to optimize!

If you're on gravity, why not go to 3/16" tubing and get natural vac which would undoubtedly help with any spout? I'm stating this knowing nothing about your situation so I apologize in advance if it's something you've already figured out won't work.

[DrTimPerkins]

… which might produce more in a season, the arch-barb or the check valve spouts?

Firstly, the two spouts are designed for very different things. The CV spout was designed to solve the sanitation problem, and is most effective about mid-season onward. The Arc-Barb Spout was designed to solve the issue of standard spouts blocking off the newest wood rings and thus restricting sap flow volume and flow rates, particularly during short thaw events (which occur mostly in the early season). A combination of the two would likely work well, but that is outside my influence to make happen.

Secondly, that particular comparison has not yet been made. It would likely take several seasons of testing to be sure of the results given that you'd want to do the comparison over a range of dropline ages. Given my semi-retirement, it isn't something I will be able to accomplish.

Third, to tip our hats just a little...we will be doing some testing this season that combine aspects of those two (wood blockage and sanitation). Can't say much more about it until after the 2024 season is over and the results are in.

Lastly, there are some really long-range things we're working on that are quite novel. Some I've mentioned (External Tubing Connectors for 3/16" tubing to resolve the fitting clogging issue as well as the Sap Caps for sap collection from saplings). Some we haven't talked about (and won't until things prove out and the timing is right). Typically, we do 2-5 yrs of development and prototype testing, then another 1-2 yrs of commercial product testing (prior to licensing and marketing), then continued testing for several years after a product is released. We have things in the works at all those stages right now.

[82cabby]

littleTapper- 3/16ths is a good suggestion. I’m geared up for 5/16ths currently and switching would require new tubing tools, replacing long lines on guide wires that are tricky to get at, that kind of thing. It is definitely something I will do in the future.

Dr Tim- thank you for your reply! I didn’t understand the distinction between the two sufficiently. Looks like I’ve got some thinking to do!

[Mooneybc]

With using the arc-barbed spouts/adapters is it recommended to still drill around the two inch depth or should it be drilled more shallow? I am thinking of changing over to the barbed adapters next season.

[DrTimPerkins]

With using the arc-barbed spouts/adapters is it recommended to still drill around the two inch depth or should it be drilled more shallow? I am thinking of changing over to the barbed adapters next season.

2” is still the recommended depth.

[blissville maples]

I have been using these check valves on and off for 10 years. When I first use them I doubted them but after a couple years I realized that my main lines were not adequate and potential ice jams inhibited the extra production.

Here I am 7 years later using them again and here's what I find:

The concept is there- on paper.
What I find even when I take them out of the bag I check some of them and out of a hundred there's always a few that don't seal even being brand new.

The problem with the check valves is that it only takes one little piece of anything to stop that ball from seating. When this happens it renders your check valve useless and it happens a lot more often than one could think. There is no test to show once the tap is in the tree if it creates a seal and prevents backflow but I'm here to tell you in my opinion 10 to 20% of the tabs end up with something between the ball and the seat.
And this is just in the first couple days.

I think one thing that has deceived me is when you walk up and look at them versus let's say a CDL signature spelt. The CDL spells have a wide open orifice that takes a whole bunch of sap on a peak flow day to fill. The check valves have a tiny orifice the middle of them not much bigger than a pencil lead so every time you go up to a check valve of course it's going to look like they are flowing more than a regular spout.

This applies to 3/16 tubing as well Since a foot of liquid in 5/16 will fill up 3/16 near 3 ft. This pertains to the spouts because the check valves take a smaller amount of liquid to make it look like they are running well whereas the CDL signature spouts takes a peak sap flow to "look" like they are flowing the same.

I am here to tell you that I used probably 3,000 check valves this year. I see just as many check valve holes dry as any others. The other problem with check valves is they plug up to the point where no vacuum can get through. Dr Tim says this happens with them all and although it can not the same extent very few CDL signature spouts will actually plug completely. He says that their job is already done well we still have a week of sap weather in my nice beautiful 20-in tree can't let any sap out because the spell is plugged. No matter which way you slice it it reduces your production, and how do you know that specific tap hole made enough sap the beginning of the season to offset the loss at the end you don't know there's no way to tell!!!!

All in all I think I'm stuck on the visual side of it the fact that the check valves look like they are running more when in fact it is the same it's just the inner orifice is smaller so it stretches it out further.

My production doesn't double when I use check valves I see absolutely no difference in yield and this was the same as it was 10 years ago when I tried them then. It's just super hard for me to get away from the concept because the concept is there on paper but that's where it stops.

[blissville maples]

With using the arc-barbed spouts/adapters is it recommended to still drill around the two inch depth or should it be drilled more shallow? I am thinking of changing over to the barbed adapters next season.

I don't know I think I would be concerned about taps heaving. It's actually one of the issues I find with check valves is that they have a lot more than any other spouts. Very rarely do I have a CDL signature spout heave from ice (actually I think it's more of the bark on the bigger trees as the smaller trees never do it, I believe the bark shrinks around the tap when it's cold and slowly pulls it out)

The bottom line is you have to drive in a spout a certain distance, to try to get sap out of the first layer underneath the cambium is kind of ridiculous. Furthermore, and I've read the study about closer to the cambium the sweeter the sap. But if vacuum can pull sap from one side of the tree to the other and out of the ground and everything else if your TAP sits in the fourth annual ring how can it not be sucking from the first second and third annual ring? I mean come on here! I'm all about studies but sometimes I think they're ridiculous because you can't tell me that your TAP isn't sucking from every part of that tree that's encased by bark.

It's kind of like the studies I've read about driving your spouts in too far I have been very focused on this in the last couple years and it has caused me more harm than good. I drive spelled shallow sounds like they are seated definitely could have used a couple more taps but I leave them b because I don't want to drive them in too far and reduce yield! Then you go around all season long driving in heaved spouts, because you didn't drive them in as far as you normally do hoping you're going to get some of that sweeter sap and more of it. When in all reality you reduced your production because the micro leaks in your TAP holes are going to dry out your hole and reduce your sap flow.

At the end of the day you can only get so much sap out of a tree in a season and every year is different. I have read every study under the Sun p m r c has done and probably three times. Most of it is great but some of it you have to not focus on because it causes you more harm than good just like I found with trying to be easy on tapping. Next year I will have the 16 oz estwing by my side putting my taps in. When you're running 5600 taps by yourself you don't have time for nonsense it's one thing if you got 300 but when you get larger in size you have to do things that work and are proven.

I dunno proofs in the pudding

[blissville maples]

Firstly, the two spouts are designed for very different things. The CV spout was designed to solve the sanitation problem, and is most effective about mid-season onward. The Arc-Barb Spout was designed to solve the issue of standard spouts blocking off the newest wood rings and thus restricting sap flow volume and flow rates, particularly during short thaw events (which occur mostly in the early season). A combination of the two would likely work well, but that is outside my influence to make happen.

Secondly, that particular comparison has not yet been made. It would likely take several seasons of testing to be sure of the results given that you'd want to do the comparison over a range of dropline ages. Given my semi-retirement, it isn't something I will be able to accomplish.

Third, to tip our hats just a little...we will be doing some testing this season that combine aspects of those two (wood blockage and sanitation). Can't say much more about it until after the 2024 season is over and the results are in.

Lastly, there are some really long-range things we're working on that are quite novel. Some I've mentioned (External Tubing Connectors for 3/16" tubing to resolve the fitting clogging issue as well as the Sap Caps for sap collection from saplings). Some we haven't talked about (and won't until things prove out and the timing is right). Typically, we do 2-5 yrs of development and prototype testing, then another 1-2 yrs of commercial product testing (prior to licensing and marketing), then continued testing for several years after a product is released. We have things in the works at all those stages right now.

How do standards spouts block off the newest wood rings when vacuum can travel across the tree both horizontal and vertically? That vacuum can't travel a half an inch from the end of the tap to the cambium but it can travel from the end of the tap 18 in across the tree to the other cambium....c'mon!!!

If I'm understanding this correctly it doesn't make sense

Sugar cant jump the annual rings only water can?

[DrTimPerkins]

Good questions. Sap CAN move sideways, but does so about 10x slower than moving vertically. The issue isn’t about whether or not sap CAN move across rings, but rather how FAST it moves out. Wood vessels (the “pipes” in a tree) are oriented vertically, so sap runs up/down quite easily. Going sideways it has to run through cell walls. In short runs, you will only get a partial run of sap from the tree before it freezes up again. Get it out faster, you get more sap. In some years considerably more. In long runs (several days) it won’t make a lot of difference. With short runs it’ll make a big difference.

The structure of wood is key in understanding this. The vessels (pipes) that sap moves through in maple wood are oriented up/down and move the vast majority of sap. Going sideways can occur, but is far more difficult and/or slow. You can think of a chunk of the wood stem as a dense sponge (or sawdust), but with small straws embedded throughout it. If you had a funnel on the top and poured water in, nearly all the water would flow down through the straws, with only a small amount moving from sawdust particle to particle (along the cell walls). Now you can make the water move through the sponge/sawdust, but it will take a LOT longer to get through. That's the point...during a thaw, you not only want to get sap out, but because the thaw isn't going to last long, you want to get as much out as fast as you can get it out.

Think of it this way…would you prefer to drink out of a straw or suck water through a sponge?

[DrTimPerkins]

I have been using these check valves on and off for 10 years. When I first use them I doubted them but after a couple years I realized that my main lines were not adequate and potential ice jams inhibited the extra production.

We've done research on this concept beginning a few years before the product (Check-valves) were released. There is no doubt they increase sap yield. The amount of the increase is dependent upon several factors, the main one being the age of droplines, other sanitation practices used, type of releaser used, and vacuum level. They do NOT produce as well as brand-new droplines/spouts or as well as chlorine-sanitized systems, however people generally don't replace droplines annually (so sap yield will drop-off in the interim 2-3 yrs) and cleaning with any sanitizer is labor-intensive (and thus costly). Therefore, when you look at the economics, the CV frequently wins.

The problem as I see it is that the cost of each spout is high relative to a regular spout. That has changed a bit now that Leader was purchased by H2O and dropped the price a good amount.

Every study done at PMRC, every study done by Cornell Uihlein and Arnot Forest, studies done in WV, and a study in Canada show that the CV increases yield. In many cases these studies were done over several years or even more than a decade.

No mechanical device is going to function perfectly all the time for an extended period. A certain amount will fail. More will fail over time. As long as enough of them function to increase yield then producers come out ahead. To make a near-perfect device you'd be paying $10 per spout and nobody would use them.

So overall...use them or don't use them. Completely your choice. However, actual research studies (where sap yields are actually measured) do show they work and provide an economic benefit to maple producers above that of most alternative approaches.

[DrTimPerkins]

... if vacuum can pull sap from one side of the tree to the other ...

Vacuum can pull sap from one side of the tree to the other...but ONLY after SEVERAL days of no-freeze conditions. The reality is that in many seasons a good share of the flows only last a few hours to one day long before the tree freezes again, so we are not ever getting to that condition (vacuum pulling sap across the tree). We did not drain the tree system to the largest extent possible given the time available. That means we are leaving sap inside the tree that we might have extracted had we been able to exploit the anatomy of the tree more optimally with a better spout design. It is not a question of how MUCH sap we can get out....it becomes a matter of how FAST we can get sap out before it is not possible to get it all out (due to a freeze).

If your goal was to put out a house fire, would you rather do it with a garden hose or a firehose? It is a matter of getting the most flow out of the system as quickly as possible. The only difference is we're not trying to put out a fire, we're trying to extract sap ($) from the tree as quickly as we can.


It's kind of like the studies I've read about driving your spouts in too far I have been very focused on this in the last couple years and it has caused me more harm than good.

I do agree that there is a fine line. As we wrote, it's a "Goldilocks" problem. Too shallow driven is bad...too deeply driven is bad...just right is good. Finding that "sweet spot" is not always easy, and it is probably best to go just a hair deeper (to reduce heaving) than a hair too shallow.

Clearly overdriving is bad and clearly blocking off too much wood with regular spouts is also not optimal. Otherwise, why not drive a 3/4" deep taphole and drive it in 1/2" and leave only a 1/4" gap in the tree. I guarantee you that doing that will result in poor yield even with great vacuum. We need to sever a certain amount of wood vessels to maximize flow from the taphole. The next step is to maximize flow RATE from the taphole by reducing wood blockage in the shallowest wood rings.


At the end of the day you can only get so much sap out of a tree in a season ...

We have found several ways to get MORE sap from a tree over a season, some are simply not doable for one reason or another...others are not economical given current syrup prices (dual lateral/dual droplines are a good example). But there is clearly more sap available in a tree than what we are getting via current standard practices.

You are right that seasons are all different. Some years we saw small (but detectable) gains in sap yields with the new spout (shorter barrel with barbs) if there was an abundance of long-slow thaws. Other years we saw sizeable gains with it if there were a lot of short-fast thaws followed by a freeze. All depended upon the characteristics of the flow periods.


I dunno proofs in the pudding

Agreed.

[johnallin]

Vacuum can pull sap from one side of the tree to the other...but ONLY after SEVERAL days of no-freeze conditions. The reality is that in many seasons a good share of the flows only last a few hours to one day long before the tree freezes again, so we are not ever getting to that condition (vacuum pulling sap across the tree). We did not drain the tree system to the largest extent possible given the time available. That means we are leaving sap inside the tree that we might have extracted had we been able to exploit the anatomy of the tree more optimally with a better spout design. It is not a question of how MUCH sap we can get out....it becomes a matter of how FAST we can get sap out before it is not possible to get it all out (due to a freeze).

If your goal was to put out a house fire, would you rather do it with a garden hose or a firehose? It is a matter of getting the most flow out of the system as quickly as possible. The only difference is we're not trying to put out a fire, we're trying to extract sap ($) from the tree as quickly as we can.



I do agree that there is a fine line. As we wrote, it's a "Goldilocks" problem. Too shallow driven is bad...too deeply driven is bad...just right is good. Finding that "sweet spot" is not always easy, and it is probably best to go just a hair deeper (to reduce heaving) than a hair too shallow.

Clearly overdriving is bad and clearly blocking off too much wood with regular spouts is also not optimal. Otherwise, why not drive a 3/4" deep taphole and drive it in 1/2" and leave only a 1/4" gap in the tree. I guarantee you that doing that will result in poor yield even with great vacuum. We need to sever a certain amount of wood vessels to maximize flow from the taphole. The next step is to maximize flow RATE from the taphole by reducing wood blockage in the shallowest wood rings.



We have found several ways to get MORE sap from a tree over a season, some are simply not doable for one reason or another...others are not economical given current syrup prices (dual lateral/dual droplines are a good example). But there is clearly more sap available in a tree than what we are getting via current standard practices.

You are right that seasons are all different. Some years we saw small (but detectable) gains in sap yields with the new spout (shorter barrel with barbs) if there was an abundance of long-slow thaws. Other years we saw sizeable gains with it if there were a lot of short-fast thaws followed by a freeze. All depended upon the characteristics of the flow periods.

Agreed.

This is one of the better threads we've had in a while.
Good, candid banter here between Dr. Tim and Blissville Maples...and all without poking the other in the eye.
Thanks.

[The Heldeberg Sapper]

Thanks for all the great info guys. I only have 50 taps on gravity 5/16 split up into two separate runs. One of my runs is along a stone wall fence with southern exposure to a hay field so it gets lot of sun, the other is another stonewall fence but its running north/south and in the woods. The sunny run almost always outperforms the shady woods trees by a decent margin (especially early season). I have been running the CV spouts the last few years just to try and prolong my taphole life (not running vacuum or anything). I think next season i will keep the CV spouts for the sunny run and try the barbed spouts on my shady trees. I think that will help get a little more production out of the colder/shady trees based on my understanding of what benefits they offer.

[blissville maples]

Good questions. Sap CAN move sideways, but does so about 10x slower than moving vertically. The issue isn’t about whether or not sap CAN move across rings, but rather how FAST it moves out. Wood vessels (the “pipes” in a tree) are oriented vertically, so sap runs up/down quite easily. Going sideways it has to run through cell walls. In short runs, you will only get a partial run of sap from the tree before it freezes up again. Get it out faster, you get more sap. In some years considerably more. In long runs (several days) it won’t make a lot of difference. With short runs it’ll make a big difference.

The structure of wood is key in understanding this. The vessels (pipes) that sap moves through in maple wood are oriented up/down and move the vast majority of sap. Going sideways can occur, but is far more difficult and/or slow. You can think of a chunk of the wood stem as a dense sponge (or sawdust), but with small straws embedded throughout it. If you had a funnel on the top and poured water in, nearly all the water would flow down through the straws, with only a small amount moving from sawdust particle to particle (along the cell walls). Now you can make the water move through the sponge/sawdust, but it will take a LOT longer to get through. That's the point...during a thaw, you not only want to get sap out, but because the thaw isn't going to last long, you want to get as much out as fast as you can get it out.

Think of it this way…would you prefer to drink out of a straw or suck water through a sponge?

Very good analogies. Ohhhh there's so much more to a maple tree than people realize.

I just wish they didnt plug up as much. Why not a larger ball and seat for it maybe in the elbow not near the tree? The reason for this would be to allow small pieces of sawdust or gunk to pass. So many times I see that little black ball holding boogers and I feel because the runber ball is soft it induces bacteria growth quicker than the polycarbonate making the issue worse.

When I'm in the woods observing it seems like the sap is having a hard time getting past all of this creating a restriction. I go from tree to tree making a low spot in each drop line seeing which ones fill and which ones don't.

One tree with new drop and regular spout will fill right up, next one will be an old drop with cv and it will fill. Next one may be a CV and drop stays dry when i make low spot, this occurs fairly often. Pull any of them spouts and ream youll get 100% flow again which tells me exactly what happened!

Id like to have a tubing system consisting of two tap trees with two separate main lines. One main line all CDs one main line all regular spouts. This would all be done during the same season to eliminate seasonal differences. The trees would both be tapped on the same side north or south One drop would have a CD One drop would have a regular spout. Everything would be identical. I feel this is the only way you could honestly test these check valves. Without spending hours that I don't have going back to your studies I can't say if this has been done although i should know ive read them all 5x.

I dunno im wary of it all, but as I've always said the concept is there. It just seems to me that if no sap ever got back the tap hole that tapole would never dry out or take 6 months to do so.

Got to be a way to re design these to have a larger orfice that doesn't plug as easy and allows a more consistent seal of the ball. What about CV in the "t" or that would allow some degree of backflow? Im always thinking ��

[littleTapper]

Maybe not a ball, but a circular flap across the full width? Think reed valve on a two-stroke....

I may be able to 3D print the concept.

This is a great thread, lots of good info!

[blissville maples]

I cannot seem to scroll up and down to edit, will have to fill in the blanks sorry, i love my phone!