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jfroe939
01-02-2010, 09:33 AM
In the cheapest (and probably least effective) way possible, couldn't one incorporate a shop-vac for vacuum by creating something in between a large poly tank that fits relatively air-tight to set the top part of the shop-vac on minus the metal vacuum basin? I'm guessing there'd be issues with the vacs burning out because they're not meant to run continuously? If someone managed to make something like this that worked even relatively close to well I'd like to see it because I think they're be alot of people that could use a cheap means of vacuum. I'm not saying it would be easy to make, but it sure would be popular for if no other reason cost effectiveness. jason

DrTimPerkins
01-02-2010, 10:44 AM
In the cheapest (and probably least effective) way possible, couldn't one incorporate a shop-vac for vacuum

A shop vac motor is designed to pull a lot of CFM at low vacuum. Once you get beyond a few inches of vacuum, the CFM drops to next to nothing. And yes, you'd burn it out fairly quickly, especially since they use air to cool the motor. With a tight system you'd not have much air movement and it would overheat in short order.

RileySugarbush
01-02-2010, 10:50 AM
In addition to durability and noise, Shop Vacs are designed for high volume flow without much vacuum pressure. Only about 4.5 inches of mercury which is not much compared to a real vacuum pump.


Dr. Tim beat me to it!

flooder
01-02-2010, 12:24 PM
I know a guy that uses a shop vac on 400 trees and last year only made between 40-50 gallons.Probably the shop vac had something to do with the low yield.

Russell Lampron
01-03-2010, 06:07 AM
This topic has been discussed on here before. Royalmaple did some testing and found that his shop vac only produced about 2" of vacuum. Not enough to pull sap in my opinion.

Brent
01-03-2010, 07:42 AM
if a shop vac worked people would have been doing it for 25 years already.

there is a reason sugarmakers make the investment

brookledge
01-03-2010, 07:06 PM
Vacuum is very strong. If a shop vac could reach high levels the plastic container would implode. The walls need to thick enough to withstand the vac. The bigger the diameter the thicker the wall needs to be. it is a good thought but that is it.
Keith

Haynes Forest Products
01-03-2010, 07:11 PM
Remember folks if you did your system right and tight you dont need the HIGH CFMs of a shop vac.

farmall h
01-03-2010, 07:24 PM
if a shop vac worked people would have been doing it for 25 years already.

there is a reason sugarmakers make the investment

Like Brent said!

Brent
01-03-2010, 07:38 PM
I don't think a shop vac would make 1" of Hg let alone 15 to 25". I couldn't get mine to lift water 3 feet to suck out the lines on the swimming pool this fall. Shop vacs are all about velocity and cfm. Actual vacuum does not move the garbage. Its the air flow that picks it up and carries it along.

To get a tree to give up sap we want exactly the opposite. High vacuum and just a few cfm's to get rig of the air that leaks in.

johnallin
01-03-2010, 07:57 PM
if a shop vac worked people would have been doing it for 25 years already.

C'mon Brent, in all fairness, you gotta give the guy credit for trying..right or wrong experimentation is a big part of this site.
Didn't you do the same with your RO system a while back?
Lots of stuff here is "what if" and some of it even works in the end.

Brent
01-03-2010, 09:24 PM
You're right John, I did experiment. But I did a lot of homework first and it worked. Like almost everyone else, I outgrew that one. Unfortunately I don't think you can get a spec on the vacuum generated by a shop vac. In fact they even lie about the horsepower on them. ( you can't run a real 3 Hp motor on a 15 amp circuit ).

Anyway, point made. I guess I am getting a little crusty. Didn't mean to be harsh.

RileySugarbush
01-03-2010, 10:44 PM
http://www.shopvac.com/specifications/ultra_pro_series.asp


In the above link, the Shop Vac folks claim 60 inches H2O which is about 4.5 inches of Hg when sealed or zero flow. I think it would over heat quickly.

Regarding the3 power claims, the 6.5 HP peak is some kind of brief dynamic peak power like Sears uses on their power tools. Actual power of the highest power unit on this page is about 2HP continuous when you look at the current and voltage.

johnallin
01-04-2010, 03:12 PM
Anyway, point made. I guess I am getting a little crusty. Didn't mean to be harsh.

You're a gentleman and you'll be fine once you get back out in the woods....
only six weeks to go.

Now, if I can only finish the work I've got lined up I'll be fine too.

Brent
01-04-2010, 03:23 PM
Yeh maybe 6 weeks for you but up here we normally don't tap till St. Patrick's Day. March 17.

Maybe jump the gun and "experiment" more with check valve spouts. Got some on order already