Air Spade?

[Keener]

I was hoping to get some input on the use of the air spade and some feedback on how effective it is for root excavation.
Any other info like how many cfm you need, cost of the tool, or if anyone has a home built version of it ect.
Seems the local tree authorities are soon to require it rather than the shovel and broom technique.
I'm all for it if it saves time, roots, and my back.
And it would be nice if it not priced like the first electronic calculators (new to market and outrageous in cost).

 

[lhampton]

Very effective for root excavations, as well as a variety of other work. I have been on projects where it was used to trench through root zones for utilities, irrigation lines and drainage. To "till" in compost to ammend under trees for planting perennials. Bore holes for aeration, check for the prescence of living roots after construction or other disturbance. Excavate along foundations to check for roots prior to landscape and home renovations. Almost anything where dirt has to be moved or removed.

The drawback is the mess. On a single tree, or a few small trees you are almost better off doing the work carefully by hand. After you set up some containment, be it plywood or tarps, to help hold in the blown dirt, then cleanup, there are times when the old way is the best way. A great tool, but I wouldn't want to have to use it for every situation.

Neighborhood of $1100.00 US. The cost is in the nozzle. A specially designed venturi that creates a supersonic flow of air. Not easily duplicated in the DIY (Do IT Yourself) models, but I'm told that for $35.00 the DIY kicks butt. 185cfm, but there is a larger nozzle that needs greater flow. Check out the folks at Concept Engineering Group.

The Airspade seems to be all the rage here in Dallas. A few years ago, only one company had one. Now I know of five (probably a few I haven't heard about also), and everyone is talking about it. The company I work for is set to order one this next week.

I think the thing I like best is that it opens up another avenue of tree care that we have really been neglecting. In the Dallas area, most of the trees we care for are planted. Most are planted too deeply. After getting called out to "save" trees after its too late, it is nice to be able to do something proactive. Pruning, removals, sprays... Treating symptoms. Sure we can get down on hands and knees and scratch away the excess soil, but how any times do we really? Spend $1100.00 on the Airspade and $300.00 a week to rent a compressor and you can bet you'll sell some root collar excavations. You'll start looking at the base of the trees when you walk onto a property, and then look up, which really is what we should be doing most of the time anyway.

Louie Hampton

 

[Keener]

Thanks for the input Louie, my concern over the price seems somewhat warranted when the exchange on the dollar makes it $1400 or so Canadian.
I am not doubting that it is a great tool, just out of reach for the small company.
Mind you if I sold my chip truck it might just pay for one with the freight included.
Do you know the outlet hole size on the model that you are familiar with?
And do the neighbors get their stucco covered in dust 3 or 4 houses away? This can be an issue when stump grinding during the summer especially. The guy next door has no sense of humor when he happens to be painting the exterior and the grinder is adding a dust topcoat.

 

[Kneejerk Bombas]

If you go to the ISA webboard and look at a thread called "VerticalMulching/radial trenching/urbansoil repair " you will see a detailed discussion of a homemade tool.

I've used it in many situations and the mess is not a big deal. If the soil is moist you don't get any dust. Big particals don't fly very far, if there is a new car nearby, move it.

 

[John Paul Sanborn]

Mkae sure windows near by area are closed. Especially down wind.

I've heard of people having a hose with a misting wand on hand...

 

[Keener]

Thanks JPS and Mike the thoughts are appreciated.
I really think that the " if there is a new car nearby, move it" idea is a good one.
I think I will make it policy for any of the tree work I do.
Just have to figure a way to do the same with the house.

 

[John Paul Sanborn]

I don't use my air tool very often, but when I do it saves my back (and finger nails)

Also have some old Felco's and a saw handy to get fine roots out of the way.

I've done a little work lately where I blow back all the soil around sprouts on Prunus and Malus, after having an NAA application several days prior. Then prune the sprouts back and reapply the ANN to ther fresh wounds.

I'll have to let everyone know how it turns out next year.

 

[TREETX]

Originally posted by lhampton
You'll start looking at the base of the trees when you walk onto a property, and then look up, which really is what we should be doing most of the time anyway.

Amen. It is really an under emphasized practice.

I have solved many an case of the declining post oak/cedar elm/planted live oak/etc by doing just that.

 

[Kneejerk Bombas]

.

 

[Kneejerk Bombas]

Holes filled with compost.

 

[Kneejerk Bombas]

Area raked out.

 

[Kneejerk Bombas]

No flair.

 

[Kneejerk Bombas]

Down about 12", not much to do here, what a mess.

 

[Kneejerk Bombas]

We left the grade down and dished the area out. This is an example of a tree not much could be done with, at least we removed the soil from the trunk.

 

[Kneejerk Bombas]

This small pine was down about 6". The soil was very hard and compacted. Roots all around the trunk.

 

[Kneejerk Bombas]

Area cleaned up.

 

[Kneejerk Bombas]

The tow behind compressor was 375 cfm, but the 175 cfm and 185 cfm compressors that we used in the past worked just as well. Those are the only thre compressors we ever used. I suppose with the big one you could run two or three spades at once.
We made the holes about big enough to put one shovel full of compost in. You could make a small hole in the surface and twist the spade to make the hole cone shaped, to wreck less grass but hold more compost. They went down about 6" or 8".
One guy with the air tool went faster than two guys filling them back up and raking.

 

[murphy4trees]

2 questions Mike

How do you sell that work?

How much do you charge? I would guess it's T & M.
Thanks,

 

[Kneejerk Bombas]

We charge the same as our tree climbing rate, plus add a little extra for the compost. The stuff used was called potting soil, it's a mix of sand, sea shells, composted cow manure, and mushroom compost, and it costs about $30 a yard.

We sell the work so we can just come do the job when we have several jobs lined up, like stump grinding, so we have a whole day of it. Because we don't have our own compressor, the $100 rental fee gets spread out over several jobs.

How effective the hole method of adding compost is debatable, usually we spread compost on top and do the whole area that is compacted. This customer didn't want to redo his lawn.

 

[Keener]

So I took Mikes input and built the airspade.
Used it today with 375 cfm compressor and had good results in two areas, moving the topsoil down to the hardpan and boring holes straight down ( 2.5 ft ) to check for bedrock.
Blowing away the hardpan was very slow and I would not want to trench any distance or depth with my version of the airspade.
Does anyone know just how well the commercial model works on clay type hardpan?
It seems to me the roots go to the hardpan level and run along at that depth, if you wish to undermine to place services you will be working largely in the hard stuff.
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