"Dust Collection" Sort of

[Carl Eyman]

I need help deciding if the following idea will work before spending the money to try it,

In front of my condo are four magnolia trees. They are pretty, give good shade, but are messy. They drop leaves all year long and these are hard to pick up. Not so bad when they land on concrete. The yard people blow them into a pile and pick them up, but on the areas with ground cover, they are tough to harvest. The grounds maintenance people will not pick them up there without an extra charge. So, My Solution:

I propose to get one of the plastic covers for a 30 gal. trash can that converts the can to a cyclone. Then with a shop vac pull a suction on the can, suck the leaves into the can lined with a plastic bag, and set the bag out for trash pick-up.

I've tried this without the cylone directly into the vac with a 2 1/2" hose. One would need a 4" hose. While the vac has enough air movement to pick up the leaves, the 2 1/2" hose is too small and clogs up. A 4" hose would probably do it. My QUESTION IS:

Would a shop vac move enough air to allow the use of a 4" hose? My reasoning is that the velocity of the air movement is an important factor in moving materials pneumatically. The velocity will be down in a 4" hose compared to a 2 1/2". Will enough remain? I hate to buy the hardware and find it won't work.

Ok, you wise woorworkers, share your knowledge.

[Jim Becker]

Likely, you will not get a good result with a 4" hose. Vacs work on high-pressure; low air flow. 4" hose doesn't help with that.

[Jason Beam]

I agree with jim ...

the area of a 2.5" diameter circle is: 4.9"
the area of a 4" diameter circle is: 12.5"

So you can guestimate that your airflow will drop to about 1/3 of that going through the 2.5" hose when you switch it to a 4" hose.

[Mike Heidrick]

Any gas (and some electric) leaf blower pretty much is also a mulching yard vaccum. You mount the vac tube on the bottom and a filter bag goes on the output. Some like the troy built do not even have to be converted. Suck up all the leaves and sticks and dump the bag in your trash can.

[Jim Grill]

This is completely unrelated to woodworking or DC, but I have a similar problem every year when the leaves fall.

I used to rake them, then I bought a big leaf blower, then I learned a trick from a neighbor. I run over them with a mower with a bagger, which clogs almost instantly. I keep going. The mower will make confetti out the leaves. After running over the whole yard a few times I unclog the bag and then mow over it all again and dump the bag into a trash can lined with a lawn bag as needed.

It really cuts down on the volume of leaves. I used to have no less than a dozen bags two weekends in a row (24 or more in total). Now I have less than half that and, most importantly, the work is a lot easier.

There will be a small amount of "confetti" left in the yard that the mower can't get, but it will decompose very quickly. I have a large yard and use a riding mower, which makes it fun as well as easy, but the same thing will work with a push mower.

I have a 10HP chipper shredder with a leaf hopper and I also have a leaf vacuum. Neither of those compare to the ease of the clogged mower method.