Vacuum for SMALL producers?

[Larry]

I am looking for ideas. Is there such a thing as a reasonably priced vacuum system for my very small backyard sugar bush? Home made options gladly considered.

I have 250 taps in all on tubing. My slope is gradual, but sufficient. Since switching over to health spouts and the new tapping protocol (no more than 10 taps on each 5/16" line) 4 seasons ago, my yield has decreased dramatically. Coincidentally, the weather conditions have been marginal during this period. None-the-less, my theory is that I've lost any natural vacuum that I once had.

Thanks in advance,

Larry

250 taps on pipeline
2x6 Leader WSE Evaporator
Northern New Hampshire

[maplehound]

keep your eye on auction notices. If you can find a zero milk tank they can be vacuumed thus eliminating the need for a reciever. Also if you can find a small 1 or 2 hp milker vacuum pump. The smaller vacuum pumps and smaller milk tanks sometimes can be had fairly resonably cheap.

[Russell Lampron]

Like Maplehound said look for a dairy auction or a farmer that is selling out. An older dairy vacuum pump will maintain 18" of vacuum with no problem. I have a Delaval 73 with a 3/4 hp motor on it. I have about 200 taps on it and it works great. Without it I wouldn't have made nearly as much syrup as I have this year and I am still well below last years total. The 200 on vacuum has well out produced the gravity tubing and buckets which have done almost nothing.

Russ

[Jim Brown]

Gentlemen; I tried a 'Red neck' vac system on 30 tap I have in my yard this year and it worked pretty good .Take a steel drum and in the small opening place a tee.One side of the tee place the 6 way spider on the other side a small valve. In the large opening of the drum place a connection that the 2 inch hose from a large(OLD) shop vac will slide over. Hook up the lines and turn it on! I pulled with that old vac untill it started to bend the drum!The small valve is to let a vac leak so as not to crush the drum.I used it for two(2) weeks straight and that thing still was running when I removed it. Took it back to the garage and the crazy thing runs fine! Can't kill a good (OLD)Craftsman shop vac.
Just a thought
Jim

[markcasper]

How would a shop vac have enough suction to collapse a barrel? How could the vac run that long? It's certainly be under stress when its trying to pull on itself for that long?

[802maple]

Tests have been done in Canada that supports the theory of health spouts do not run as well as 7/16's under a natural system without vacuum. So if you want the so called tree savers you need vacuum and I agree with Russell and others search out farm auctions and you will most likely find an inexpensive option, ie. vacuum pumps and zero tanks although most zero tanks go at a minimum of a dollar a gallon

[WESTVIRGINIAMAPLER]

One way I found to overcome this is put 35 to 40 taps on one lateral line. I tried it this year with between 35 to 40 on 1 line and 43 on another line and it was amazing how much sap these lines ran per tap. Don't have an exact amount, but it was above the rest of my taps.

[Jim Brown]

Mark; That old shop vac pulled a dent in the drum untill I opened the small valve and let the thing pull some air. I thought the crazy thing would burn out in one day (no loss 20 years old)That stupid thing sat and ran for a aweek and a half Nearly non stop,in the rain and all and never quit. We were having problems with our vac pump in our small bush and my son suggested we take the shop vac over to run the releaser!(we didn't) we fixed the pump.
If a person has a few trees around the yard or the farm buildings and would like to pull some vac on them it worked for us.I did it just to see if it would work since we have large system in the woods and this was within sight of the sugar house and the trees were with in 40 yards of the house.I don't think I would recommend for a perm solution but who know
Jim

[Russell Lampron]

The shop vac has a float in it to stop the flow if you should happen to overfill the barrel too. No releaser needed.

Russ

[Breezy Lane Sugarworks]

You will certainly find something at a farm auction. BUT if you are to get a milk tank from a farm, make SURE the arrangements to remove the tank are made prior to the bidding!! Not many farmers are that hard to deal with, but I had some bad luck when I bought my tank, but things are all set now and I'm using it! I am using an old delaval 75 from my grandfather's barn and i converted it to a gas engine and it pulls 18" no problem. It'll do 22" easy, but i don't dare leave it alone doing that much. I'd rather have it last!

[danno]

For a sap releaser, some producers have been using old glass dairy milk releasers. They say they work well for 200 taps and under. (do a search on this web site for bender or milk releaser.) I could not find one when I was setting up my system so I bit the bullet and bought a Lapierre - works great.

Anyway, a dairy farmer called me tonight and asked me if I was interested in an old dairy releaser. I told him "no", but also directed him to this site to post in the "for sale" section. He had some used vacuum pumps he was looking to sell as well. Keep checking out those sale items - maybe he will post.

[SUGARSMITH]

I have a vac pump I would like to sell, Its a delavel,model 77( I think ) worked great but out grew it. I dont know what it is worth and its located in CT.

Let me know if you are interested and I will send some pictures.

Dan

[tuckermtn]

Might also consider a sap sucker style pump...peristolic pump(mine is a Cole- Parmer) that squeezes surgical tubing to create vacuum but doesn't require a releaser. pretty simple, but the drawback is they do not produce a lot of vacuum. I'm running one this season and with some tweeking I can only get it to produce about 6" of vac. But I only have 140 taps on that system...

[Bucket Head]

I have 44 tree saver spout's on a single 5/16 line. The line is close to 400 feet long and has a thirty foot drop in elevation from the start to the collection point. I put a gauge on it this season and it pull's almost 8 lbs. of natural vacuum.

I have another line that is a little shorter with 31 tap's on it. It must have some loose connections on it because it is only showing a pound and a half of vacuum there.

Next year I am going to make darn sure that it's leak free! Eight pound's of "free" vacuum is a good deal!

Steve

[Larry]

Thanks for your ideas. Keep 'em coming.

Right now, I am leaning towards trying to create natural vacuum by putting about 35 spouts on long 5/16" lines. This is what I had before I took the advice of the "experts" at Proctor Maple Institute. I went one of their seminars where I learned that one shouldn't have more than 10 taps on a line -- even gravity systems. This is a bunch of hooey! I have done some experimenting too and am a firm believer in natural vacuum. I have 1,500' of nice straight 3/4 inch line that will make a great highway for my long 5/16" lines.

Have a lead on a sap sucker too......we'll see.

Looks like we're heading into fantastic stretch of weather. I think I'll have to sneak out of work a bit early and start gathering.

Larry

[WESTVIRGINIAMAPLER]

The guys at Proctor get funded and lots of donated equipment and what they say has a lot to do with more tubing sales, etc. 1+1 = 2

[TapME]

I have 40 taps on one side of my bush and I am wondering about a shop vac system to try vacuum on them. I've read some of the post and would like to ask advise on how to set it up. A little history I've never done tubing, but Parker gave me a crash course and I think I have a good clue. Vacuum on the other hand I have no clue. I am open to suggestions, thanks lou.

[royalmaple]

Lou-

You got the 1/2 hour tour at my sugarhouse. You didn't take mental pictures and get it all figured out yet?

Stop by if you are around again and I'll show you the basics. You are still going to need a releaser of some sort, unless you are thinking of drawing the sap directly into the shop vac. But I dont think that would be your best option.

[WESTVIRGINIAMAPLER]

If you could put the 40 taps on one lateral, it would produce good natural vaccuum for free.

[TapME]

Matt, It was a very nice trip around your shack and learned a lot, now it is to put it all in to a plan. I was thinking of placing a tank in front of the vac, one that could hold some pressure and use the auto shutoff on the cleaner to stop the flow of vac. sounds primitive but seems like a plan that may work. All this would be closely watched.
Brandon, I have read all the post about a natural vac on smaller lines and will test it this coming season. More sap than we got this past year would be welcomed greatly. 7gallons on 75 taps is not a good average even for buckets, but all is greatly accepted in to our home.
We also have to consider upgrading our pans and arch. Many things to consider and little time to make them happen.

[royalmaple]

You would just have to consider the time needed to watch the vac and dump the tank from time to time as it gets full. Unless you have a tank big enough for a run. I think you'd be much happier if you had some sort of a semi automatic system set up so the jar/releaser dumped for you.

[TapME]

I read some old post that talked about the natural vac and there are some with large totals with 50 to 120 laterals on a 5/16 line. The therory behind the natural vac has some credability but the volume is staggering on some of them. I need to have more storage and would like to find a good cage tank or something like it. Royalmaple you said you new of someone that had tanks in your area. Also that first evap. you built looked good Matt, How did it work?

[powerdub]

I would be interested in seeing how the yields are for those that have so called natural vacuum. Are you getting a quart per tap or what? I know what I used to get with that kind of set up but I am interested in hearing what others are getting.

[royalmaple]

Lou-

Evaporator did work, but took lots of time to build for sure and wasn't as efficient as something you can buy. But I got most of it for free but I did have to buy the material for the pans. I think if I was going to build another one like it. I would build one large flat pan with partitions instead of trying the flue pan. Without the proper tooling(which we didn't quite have) it is a Pain in the A..

I have more time in the flue pan than I did in everything else. But if you went with a flat pan and the same concept you'd be in good shape. Darren V. in VT that is on here from time to time has a nice set up with an oil tank.

If you have any situations like I do, there is little to no slope in the land and there is only so much you can make in the woods from tree to tree so "natural vacuum" just isn't there. And if I had 100 taps on a line, that would be 100 taps that I wasn't collecting from. I would be making a natural sap dam.

Maybe when I take a ride someday I'll stop by and give you some ideas on your tubing. At least get tubing up, and have it set up so you can add vacuum. Then if you do afterwards your all set up. But be careful once you go vacuum you won't go back.

Wait till the big guys start selling shop vacs in the catalogs. But they will be food grade plastic...right?

I would be interested in how you make out but I just keep thinking the pump can't run that long with the resistance of a close system and not burn up? But I have never tried it. I am just going by what the sound is when you block the suction and it sounds like it is going to blow up.

....Captain, we need more power....I'm givin her all she's got....

[NH Maplemaker]

TapMe,At Home Depot they sell Rigid brand shop vac's whiich has a water pump attachment that hooks on to the bottom drain hole of the vac. I guess this would be used to pump water from the vac to a drain or out away from vac. Anyway, if you coud figur out how to turn the power on to this attachment pump at the same time that the auto switch shuts the vac off when full! The pump could pump sap right into your holding tank! This will take alittle thought as it will also need to do the revers when vac is empty. Hope this makes sense!! We have done this with a releaser we made! Vac off, pump on, pump off vac on!
, Jim L.

[royalmaple]

Get a shallow well jet pump, plumb it to the discharge on the shop vac, then have a float switch inside the tank to sense the level in the shop vac and have it control power to the pump. Basically just like an electric releaser.

One thing I am not sure of is typically those shut off floats are not heavy enough to break the vacuum if the tank is drained and you do not shut off the pump first. Since you normally shut the pump off when it is full take the lid off and drain it. So you'd want to sense the level in the shop vac and have the pump turn on before the shop vac was full and closed off the vacuum. Just a thought but maybe I am wrong.

[TapME]

Thanks guys for the info. MY thought in my sleep last night was to place the vac line on a y in the line on the top side and have the sap flow past on the bottom and into a tank that could hold some pressure. At the top of the line would be a gauge and value to adjust the psi. I'm thinking of 6-8 psi on a reinforced tank, maybe plastic with wood ribs to surport or maybe some aluminum, something easy to work with. I have been looking for a tank in the 150-200 range in ss, but no luck in my price range.
Matt, I do have a auto on and off switch that came with a sump pump that I have ( I think they call it a float switch) you plug the pump into it and as it rises the pump comes on and down is oposite. Would like to talk to you about you evap. and about hanging line. My drop would be about 10-12ft in 200.
Jim, I will have to go to the dumpO and check out this vac, sounds interesting.
Scott, the post that I read had 120 taps filling a 300gal tank in a 24hr time frame. that equals a qt. a miniute or 2.5gal/tap. It caught my attention.

[royalmaple]

Lou-

Scott was talking about production for the season. Like 1 quart of syrup per tap instead of sap flow per day.

I'm not sure what a shop vac can pull for vacuum. Might have to hook mine up and see.

Alot of my secrets are classified for the protection of the country and the industry but I could probably tell you all of them in about 5 mins. Just can't repeat them.

I have scheduled a special session of the minds next week. Russ will be over while on vacation to hammer on some vacation sodas and I'm sure we can invent something for you, if you can wade through all the BS.

[TapME]

If there is any other info that I can supply to the meeting of the minds just let me know. I wouldn't want it to go nuclear.

[NH Maplemaker]

Matt, I would think that when the pump at the botton of the shop vac came on and shop vac shut down , Water pump would remove sap and vac at the same time allowindg float switch drop back down! I know it works this way on our releaser. Jim L.

[Russell Lampron]

Like Matt and Maple Maker are saying a jet pump hooked up to the drain on the shop vac tank should work. I don't think a shop vac creates much measurable vacuum because if it did the tank would implode. You would only need a jet pump that would overcome the shop vacs suction.

Let us know how it works out and how much vacuum you have at the tap. There are plenty of small producers looking to increase their volume of sap without spending much money.

Russ

[TapME]

Russ, I would think that a shop vac works in the same principle as the Venturi effect does with air pressure being used to create a vacuum. A lot of good ideas have been pasted so for and are making me think even more. Good ideas start out as thoughts, great ones start the same way.
Royalmaple, a wonderful conversation about vac and releases, can't wait to see you and discuss it in more detail. I do know one thing about this whole discussion, and that is I will have tubing up on these 40 taps this coming year. The part about using schedule 80 plastic for a tank got me thinking, imagine if you used a 24" dia. pipe as a collecting tank and put a cap on the bottom with a spigot to drain off, the material is water grade.

[royalmaple]

Jim-

I wasn't thinking about turning off the vacuum. I thought it would be running steady. But yes if you interrupt the power to the vacuum and turn the pump on then certainly the ball will drop down and when the vacuum comes back on you are in business.

Did you see the stainless 16 gallon 6.5hp shop vac at Home Cheapo It was 160 ish bucks. All they have to do is scrap rigid off it and put lapierre on it and paint it blue.

Lou and I did a little jam session on the phone tonight, we have patents pending as we speak. This is gonna make it so I can retire early. I can't wait.

[maplekid]

do any of you guys have any expiriance with a ( universal vaccum pump out of an old milk house.i have the chance in getting one for 30 bucks

[Russell Lampron]

Maplekid,

Get the pump, $30 is a good deal. Get anything that the farmer wants to throw in with it too. Most likely with a good cleaning and some new oil it will work.

Russ

[Parker]

Instead of having a sump pump hooked to the vacuum cleaner tank to drain it,,,,,,could you have a 2" hole covered by a rubber flap on the side at the bottom of the tank that sealed tightley,,,mabey cut the hole with a hole saw and glue a piece of PVC pipe in there so you had a shoulder to seal aginst,,, when the tank filled with sap the vacuum would shut off, gravity would take over, the flap would open, sap would dump out of the tank,(prefrabely into a stock tank or something) vacuum would restart,, You would have to have a check valve between the vac and the mainline so sap would not get sucked back up your mainline when the vacuum shut off,,the old dairy balance tanks were set up like this, just a thought for doing it on the cheap-less moving parts= less to go wrong,,my 2 cents,,,,,,,,,, hey-come to think of it that is almost how a modern vacuum releaser dumps,,,

[super sappy]

Parker- Delaval made an old style moisture trap/ seperator that works similar to what you have suggested. It hangs in the Vac.line when milk filled the cannister. the vac was broke and a little plug dropped out the bottom and released the liquid. I gave one to massey jack last spring. That might work on low Vac. And is all stainless. -SS

[TapME]

Matt, I have sent you a poor mans pattern on the items we discussed. I will start gathering materials for a trial rum. Again , more info from traders that help me understand the cycles that have to take place, thanks. Let me know how the experiment works out on " of vac Matt. This would be a great help in the design of the system.
Parker, a release tank made from a small PVC pipe and a toilet float connected to a shaft that would open a valve at the top and bottom sounds like it would work, with vac coming in at the top and storage at the bottom. This is one of the patterns Matt and I have written up. The more this is discussed the more it seems that the concept has potential to be practical.
We talked about over heating and I think that the temp. outside in the spring would be an advantage to cool the vac. I also mentioned that I use to use a shop vac for gluing multiple layers of wood together and used a shop vac to create the vac and remove all the air, we use to run them for a 24hr period of time and never blew up one.( works better than using clamps)

[NH Maplemaker]

MapleKid,We used a universal vac pump for years untill we got to big for it. It work just fine ! As Russ said take any thing and every thing they want to give you with it!! As you can see todays junk maybe tomorrows maple equipment! Jim L.

[royalmaple]

Before you guys run out and clean out home depot or lowes or cash in your retirement for stock in rigid shop vacs. I did some tests today.


I hooked up a 1hp small shop vac to my releaser, and voila 2.5 inches of vacuum

I hooked up my 3.0 hp shop vac to the same releaser and ....2.5 inches of vacuum.

So altough it may work still no substitue for the real thing.

Parker I do like your idea of just having a flapper, only problem is that when the ball sticks to the vacuum inlet and cuts the vacuum to the tank, the flapper will certainly open and dump the sap but without cutting the power you won't be able to get the ball to drop and get the vacuum going on the tank again. The vacuum is too strong on the ball and the weight of the ball is just not enough on its own to break the vacuum once stuck to the top. So you need to either weigh down the ball somemore or interrupt the power to the vacuum temporarily.

These test were not done in a clinical environment so expect + - 25% inaccuracy. I don't have a larger vacuum to try, but might do more. I will just have to wait for the government funding to continue the research.
Governor...You got any research grants available?

[maplekid]

maple maker did yours have an electric engine or gas? and this only has the main pump nothing no motor no line nothing just the vaccum pump. what all do i need to make it operational?

[NH Maplemaker]

Maplekid, Ours was just a small one and had a 1hp electric motor on it! But the universal brand pumps came in a few differant sizes. My neighbor has one twice the size as the one we used. I think they were like the one horse tractor, used by folks that just had a few cows that they had been milking by hand!
All you need is 1" black plastic from the vacuum port to a releaser of some type! Not all that complicated. Jim L.

[TapME]

With Matt's research on shop vacs it is apparent that you may not get 6" of vac. But the good side of the story is that it is better than the average low pressure system. We all know that sap flows best when a low pressure is upon us, thus at 2.5" of vac is like having a low over you all the time is it not. This is the first of the trails , let's see if other ideas can improve the inches. Better hoses, less leakage around the canister, smaller hose line are the ones that come to mind would they make a difference, it's not about horsepower. Let me know if I am off base here.

[royalmaple]

I just got a funding grant and I think I have the .75 it will take to do the ultimate test. I'll have to drive down to the local car wash and take my releaser with me and hook up to that vacuum cleaner. You know that has to be the strongest vacuum cleaner on the market.

Stay tuned.

[Jim Brown]

TapME; I put together a 'redneck' vacumm system last year . These were 39 taps I have in the yard so I could watch them while boiling Used a steel 55 gallon drum with a plastic lining. Hooked the shop vac to the 2" hole in the drum and place a 6 way in the small opening and hooked the 5/16 line to it.
Started the vac up and pulled the sap to the drum. When the drum got full ,turned things off and pumped the drum empty
Works for Me!
thanks
Jim

[TapME]

Jim, how did the flow to the drum do? Would like to know more. thanks Lou

[802maple]

Not to sound like a smart *** but if that drum didn't collapse you didn't have a enough vacuum to produce any significant amount of extra sap. !6 inches of mercury would have folded that style of drum up like a pretzel, and 16 inches isn't enough to produce high yields. Keep trying as I am a promoter of low cost equipment , but I tend to believe Matts research on this one

[Jim Brown]

It doubled the productions from those taps from previous year. I had a slight dent in the side of the drum and the shop vac was an old 16 gallon craftsman I had in the garage.The motor got hot but never quit. I intend to hook it up again next spring. I never checked the inches of vac pull.

[TapME]

It is true Royalmaple!!!!!!!!!! you have been chosen for the grant. We only need you to fill out the forms we sent you to receive your grant money. here is the site to get your forms from bs@dot bs.bs. Please fill them out in quad. and wait to receive the money by mail.

On the other side, you will not get any more vac out of them at the car wash. It's just the type of system they are. My thoughts are shattered that a shop vac will not collapse a 55gal drum. This is one for the myth Busters to take on.

[TapME]

Jim, thanks for the info. If I had doubled my sap last year I would have had a normal year instead of the 1/2 that we received. Sounds pretty simple to hook up too. Matt did the " thing and got only 2.5.

[TapME]

Gov. Are there any papers on vacuum that were published on the increase of sap with the increase of inches of vac? TapME

[802maple]

All right I am sorry if I hurt anybodies feelings as that certainly wasn't my intention. I understand that you may have doubled your production as it would must certainly help, anything would do that. I only said that about the drum to reinforce Matts research as it would probably only take about 5 to 6 inches of vacuuum maybe a little more to collapse that style of drum. What makes more sense to me is to find a vacuum pump from a farmer such as Maplekid did for $30 dollars as they are out there and a heavy duty drum like the old Galvanize syrup drums that are readily available and do the same thing that you did with the 55 that style will hold high vacuum in the 18 inch level or atach 2 drums together. Just my opinion

[ennismaple]

Gov. Are there any papers on vacuum that were published on the increase of sap with the increase of inches of vac? TapME

As a rule of thumb: Vacuum will roughly double the sap yield compared to gravity. Our bushes that were on gravity but our now on vacuum produced double (or more) sap.

As for increasing sap yield from an existing vacuum system: Sap yield increases linearly with vacuum. This means that if you're running 15" Hg and increase the vacuum to 16.5" Hg (a 10% increase) you should get 10% more sap.

[Jim Brown]

We just used the drum and vac thing to play around with in the yard.(more or less just to see if it would work at all) We have two large vac systems that we use in the main bushes both run on generators and mechanical releasers.(20 cfm and a 30 cfm pumps)With the poor year we all had last year we more than doubled our sap out put with the vac. Like a lot of others we would have had a bad year with out the vac. We held 16.5 on our pumps and did not over heat them and very little oil comsumption.
Thanks
Jim

[TapME]

802, no hurt recorded here. My thoughts were crushed (ha, ha) when I learned that the shop vac didn't crush the barrel. All good ideas have to have roadblocks to over come to continue on. The post by ennismaple has again added more good info into the mix. Now for a thought(don't be scared) if you start out with no vac and add it to the mix at 2.5" how much of a gain would that be in sap? Say the quantity was 100gal from 100 taps and you add 2.5" of vac. what would be the increase in sap? Jim increased his volume by 100% with a shop vac. Would this be true of most under average conditions? I have been looking for items to upgrade, just thought that on hand items and easy assembly would fit the bill better. This would only be about 40to50 taps as all the others are not conducive to having line set up. The new additional taps are all large sugars in small bushes in peoples front yards, and buckets are the only option. Have 85-100 already lined up 5gal buckets with line taps going to them, all within 2 miles of us.

[Mike]

Beware when running HIGH VACCUM on warm days..I hear a guy up hear ran over 30 and sucked in his main lines.....................

[802maple]

If he had 100 psi maniline he shouldn't of had a problem. Did you mean 30 degrees or 30 inches of vacuum?

[Jim Brown]

I don't know too many pumps that will hold 30 inches for very long with out getting too hot! Ours will pull 30 but the pump and motor get very hot REAL FAST!

[802maple]

There is a reason for that and I believe that you can't pull anymore than 29.8 inches of vacuum or somewhere near that number is absolute vacuum which takes a ideal world to acheive.

[royalmaple]

I found some research papers on the topic that was asked above. What was the different results for more or less vacuum. Thanks to the Gov's nifty CD I found some topics and studies. Keep in mind these were all done a while ago and results may change with new equipment, tubing or practices but intersting. I'll try to post the topic so you can read the whole study.

I may have to post in several posts to get it all on here.

[royalmaple]

Since the advent of the dosed-tubing method of collecting sap from sugar maple, many producers have adopted the use of vacuum pumps to induce sap flows and to increase the volume of sap collected per tap. It has been well-documented that vacuum pumping can increase sap yield from a maple sugarbush (Blum and Koelling 1968, Morrow and Gibbs 1969, Laing and Arnold 1971). It has also been demonstrated that, in general, higher levels of vacuum result in collection of higher volumes of sap (Smith and Gibbs 1970, Laing et al. 1971, Walters and Smith 1975).
Smith and Gibbs (1970) examined the effects of low-vacuum pumping (5- and 10-in. Hg) and gravity sap flows from paired sugar maple trees. Sugar concentrations from the pumped sap were not significantly different from the gravity sap. High vacuum pumping levels were not examined.
Laing et al. (1971) examined the effects of high-vacuum pumping (defined as ". . . more than 15-in. Hg as measured at the pump"), on volume and composition of maple sap. Their results demonstrated a 73% increase in sap volume with vacuum pumping and no significant difference in either sugar or other solutes in the sap. Precise vacuum levels were not measured at the tapholes nor were performance data obtained from individual trees or specific vacuum levels.
In recent years, with improved technology and equipment, it has become more common for producers to employ high-vacuum pumping (15-in. Hg or more) in maple sap collecting. However, a position continues to be held by some maple producers that while high-vacuum pumping may produce more sap, its resulting sugar content would be noticeably lower than that of sap collected with low levels of vacuum or by gravity. And, due to the high energy costs of processing maple sap to syrup, the economic gains to be realized in processing higher volumes of sap with lower sugar content are questioned. The purpose of this study was to attempt to resolve this issue by comparing the volume and sugar content of sap collected under carefully controlled conditions from individual trees at 0-, 10-, 15-, and 20-in. Hg of pumped vacuum.

[royalmaple]

The study was conducted at the Cornell University, Uihlein Sugar Maple Research- Extension Field Station in Lake Placid, NY. The specific study site was located in the Field Station's 197-ac sugarbush, which has an easterly aspect with 3%, slope and an elevation of about 2000 ft. The soils are strongly acid (pH 4.7), deep, welldrained sandy loams of glacial till origin. This is a relatively cold, high-elevation sugarbush, consisting of rather slow-growing trees. The sugarbush was developed from forest-grown trees, the oldest of which are now about 100 years old. Trees selected for the study are about 70 years old. The sugarbush was essentially unmanaged until about 15 years ago when a thinning program and other management activities were initiated. Since that time syrup production has averaged about 0.29 gallons per tap (Morrow 1982).

[royalmaple]

Following a period of preliminary experimentation during the 1984 sap season, 32 sugar maple trees were selected for study during the 1985 and 1986 sap seasons. The selected trees were healthy, vigorous, and free from obvious defect. They averaged 12.6 in. dbh (10.6-16.7 in.) and had an average crown diameter of 18 ft. Previous to this experiment the trees had not been tapped.
For each year of the experiment, the 32 selected trees were randomly assigned to one of four treatments (eight trees per treatment): no vacuum (the control group), a low-vacuum of 10 in. Hg, and two levels of high-vacuum, 15 in. Hg, and 20 in. Hg. Each tree received one tap at about 40 in. from the ground. All taps were placed on the same side of the trees, generally south (1985) and southeasterly (1986). Tapholes were sanitized before spile insertion with a 517, chlorine solution (5.25% sodium hypochlorite). Paraformaldehyde pellets were not used.
Sap was collected in vessels 30 in. long by 4 in. in diameter constructed from PVC drain pipe (fig. 1). The bottoms of the vessels were permanently sealed, and the tops were fitted with threaded plugs temporarily sealed with latex sealing compound. These 6 qt. capacity vessels served as containers for collection and measuring sap and as vacuum chambers. As designed, they were capable of withstanding at least 25 in. Hg vacuum without collapsing or leaking. Vacuum lines were fitted with a shutoff valve close to the collection vessels to permit opening an individual pressurized vessel without disrupting the vacuum to the remaining vessels within a particular treatment group. Collection vessels were held in place at each tree by a rubber strap. Droplines Of 5/16 in. tubing connected the tree taps to the collecting vessels. Other than the absence of a vacuum line attachment, the collection system for the control trees was identical to that of the trees receiving pumped vacuum.
Figure 1. A typical installed sap collection vessel.
Vacuum was supplied by three, 2.3 cfm, compressor- type, dry pumps driven by a single, 7 hp, gasoline engine. Vacuum was transferred to the collection vessels via 5/16, in. plastic maple tubing lines. Vacuum gauges were installed at the beginning and the end of each vacuum treatment line. Vacuum levels were monitored on an hourly basis whenever the experiment was running and were adjusted, as necessary, to maintain them at the desired levels of 10, 15, and 20 in. Hg at the tapholes. The system was reasonably trouble-free, and it was possible to maintain the desired levels of vacuum, in most instances to within 0.5 in. Hg throughout the experiment.
Sap was collected from all the trees during 11 collection periods in each year of the study. The total operation of the sap collection system was 72 hours in 1985 and 58 hours in 1986, for an average collection period of 6.5 hours and 5.2 hours, respectively. This sampling program represented 42% in 1985 and 55% in 1986 of the actual sap flow seasons based on 26 flow days in 1985 and 20 in 1986. A sap flow day was defined as a 24 hr period during which 0.5 qt or more of sap was collected per tap.
At the end of each collection period, vacuum pumps were turned off, and droplines to all containers were immediately disconnected. Sap volumes per tree were measured to the nearest 0.1 qt, and sap sugar content, expressed as total solids, was measured with a calibrated refractometer to the nearest 0.1%. After measurement, collected sap was discarded, and the empty containers were resealed. At the beginning of each collection period, droplines were reconnected in conjunction with reactivation of the vacuum pumps.

[royalmaple]

During the 2 years of the study, 704 measurements each of sap volume and sugar content were obtained from the 32 trees for 22 collection periods. In that yearly variation was not a primary focus of this study, data for the 2 years were combined. Mean sap volume values per tap for each treatment were computed. Mean sap sugar content values, weighted by volume, were likewise computed. Potential syrup production mean values per tap were then calculated from the volume and sugar content values. Analysis of variance, single classification, was used to detect significant differences between treatments (Snedecor and Cochran 1980). A summary of statistical comparisons between vacuum levels is given in Table 1. As expected, total sap volumes were higher for all vacuum treatments than for the controls (Fig. 2). The lack of significant sap volume increase between 15 in. Hg and 20 in. Hg of vacuum suggests that vacuum levels may be approaching the upper limit of practical effectiveness for this collection system. Larger sample sizes at the higher vacuum levels will be required to verify this result.
Table 1. Summary of vacuum level ANOV comparisons for average per tap sap volume, sap sugar content and syrup.
Sap Sap
Vacuum volume sugar Syrup
level F-value F-value F-value
0 vs. 10 11.50** 1.11ns 11.33**
0 vs. 15 75.29** 0.40ns 37.50**
0 vs. 20 78.15** 2.11ns 50.00**
10 vs. 15 16.78** 0.51ns 7.00*
10 vs. 20 21.83** 0.14ns 4.50*
15 vs. 20 0.004ns 4.09ns 0.67ns
ns = no significant difference
* = significant difference at P =< 0.05
** = highly significant difference at P =< 0.01
Figure 2. Average sap volume, sap sugar content, and syrup volume per tap for each vacuum level. Length of boxes indicates total range of individual taphole averages. Shaded areas indicate +/-2 standard errors of the mean.
The lack of significant difference in sap sugar content between the control trees and those receiving the three levels of vacuum (Fig. 2) supports the previously reported work of others (Smith and Gibbs 1975, Laing et al. 1971) and the observed operational experience with vacuum pumping at the Uihlein Field Station (Staats and Kelley pers. obs.).
The results of the comparisons between the amounts of total syrup produced (Fig. 2 and Table 1) are predictable from the highly significant differences observed in sap volumes and the lack of significant differences in sap sugar content at increased vacuum levels. Ultimately the amount of syrup produced per tap is the primary concern, and from this study the use of high vacuum pumping appears to be justified.

[royalmaple]

This experiment strongly supports the position that high pumped vacuum does not result in the collection of sap of significantly lowered sugar content. This work also reinforces previous investigations that attribute substantial increases in collected sap volumes to high-vacuum pumping.
The results of this study further indicate that the optimum level of vacuum, applied at the tap, in terms of both sap volume and sugar content is about 15 in. Hg. The added expense and practical difficulty of attempting to maintain vacuum levels at the tap of greater than 15 in. Hg are not warranted. The importance of good collection system maintenance cannot be overemphasized. Very small leaks in the tubing and at fittings can easily prevent the delivery of vacuum at the taphole. Installation of vacuum gages in the sugarbush is the only accurate way to monitor the level of vacuum actually being delivered to the trees. Producers should exercise care that they use vacuum pumps of appropriate capacity that match the sizes and lengths of well-graded sap lines according to the number of taps in the system and other characteristics of the sugarbush.
The advantages of vacuum pumping are clearly demonstrated during sap seasons characterized by less than optimal or "weeping flow," conditions. Under such conditions a sugarbush under pumped vacuum at the level recommended herein will often produce a good syrup crop when nearby gravity flow sugar bushes yield a very poor crop. For example, syrup production at the Uihlein Field Station during the industry wide, generally disastrous seasons of 1986 and 1987 was 85% to 90% of an average crop. This is in contrast to the experience of many producers in the same locale, not using high vacuum pumping, who produced only 30% to 50% of an average crop of syrup (Staats, pers. obs. and unpub. Records Uihlein Field Stn.).

[brookledge]

Like 802 said the most vacuum you can pul in an ideal situation is 29.92"Hg. or 760 torr. A good pump will come close to that but not quite there. A guage that shows over that is not accurate.
Keith

[802maple]

That is a interesting read though it is not compatible with todays setups. Looking in my old records 1987 -88 were the best years I had before putting in vacuum. I put in vacuum the following year.

1987 I had 1837 taps all on tubing with no vacuum I produced 935 gallons
1988 the same 1837 taps and made 870 gallons
1989 on vacuum 1912 taps 715 gallons produced

I think that they will find those years were very good for high elevation cold sugarbushes such as mine and the Uhlien operation whether you had a good vacuum system or even a good gravity system where a low warmer operation made little or no syrup. A sugar maker friend in the Brandon, Vt area in 1987 had the poorest record I have ever seen , having some 1800 taps and never got enough to boil the whole year.

[TapME]

Thank you Matt and Gov., the study was an interesting read and supports the addition of adding vac. It was to bad that they didn't do the study down to smaller levels of vac(2.5")It would have been interesting to see. Matt you are one h__l of a typer.

[royalmaple]

Yeah, look at the post times. Lightning quick, copy and paste technique.

[TapME]

WOW!!!!!!!! you are faster than I thought.

[TapME]

going to look at one old milk vac this weekend, will keep you posted as to what size it is. May be way to big for what I need. Use to use on 70 head.

[Parker]

I might be able to find a small one,,think I know where there was one,,also might know where there is one like I set up Tucker Mountian with,(dont need a releaser with BUT it only develops about 5" vac.),,if your interested,,

[TapME]

I'll keep it in mind. Glad to see that you will try to make some syrup this coming season.

[Russell Lampron]

Just got back from a vacation in Maine. I was there to witness Matts vacuum experiment and 2.5'' was all that the shopvac would pull. He had it all clamped up nice and tight and the releaser was plugged as well so there was minimal leakage.

The Captain and "boiling sodas" were flowing but had no impact on the test results.

Russ

[brookledge]

for the amount of electricity that the shop vac would use to only get 2.5" of vacuum you would be wasting $ for the little benefit it would give. At that amount of vacuum it wouldn't even reach the trees.
Way to go Matt and Russ the maple myth busters
Keith

[TapME]

Here's a taught, Has anyone tried to use a compressor pump as a vac buy plumbing it the opposite way? They compress air so they must get it from somewhere, like the intake. Am I off base here. Have two dead compressors but the pumps work but the regulators don't.

[nhmaple48]

I remember reading about someone who took 2 junk pickups,used one to power the other motor that was used as vacume pump.

[brookledge]

You need to remember that what ever you are trying to use was or is designed to tolerate the strains put on by vacuum.
For instance I have seen intake manifold gasket that where sucked in just from normal engine running now if you use an engine as a vacuum source you would probably need to redesign the intake manofold. As for compressors, many rotary vane vacuum pumps are designed to be used as compressors up to acertain pressure.
I know everybody likes to create things that save $ , myself included but You must also think on the amount of $ it will cost to run it.
I can only imagine on the amount of gas that old truck burned in a day turning another engine to create vacuum.
Keith

[TapME]

I was thinking that it takes in air so it must create a vac. Mine are oil bath cylinder type compressors that have been around a while. Don't know if the piston rings would hold a vac or not, and as far as using the tanks to hold vac it raises question that need to be looked into first. This may be a mythbuster question. My old compressor head looks a lot like a surge head, cast iron and all with 3/4 intake and exhaust, condensation /separator tank and oil bath with a 5hp electric motor.

[Russell Lampron]

I heard of someone that was going to use a compressor head as a vacuum pump but never heard if it worked or not. I wouldn't use a compressor tank for sap, there is probably some oil from the compressor in it.

Russ