# The next best thing to a shovel!



## Cuda (Mar 16, 2009)

If you do a lot of trenching and digging this is a must have tool!
It's called the Air Knife, or another company calls them the Air Spade.
It is a air lance with trigger like a pressure washer gun they are used in trench rescue, potholing on vacuum trucks, and landscapers use them to dig around trees to not hurt the roots. They require a good size compressor like a trailer compressor to work quickly but do have some smaller models.
The thing we use it for is when we dig down 7 feet for a sewer repair the last 2 feet are always hard pan near the line and you can't go crazy with digging bars etc. because you may hit the line where you don't want to, plus gas lines and any other utility. The supersonic blast from this tool turns the hardest soil in to pure fluff. It makes big rocks just drop out of the soil. It digs under the pie to get the room you need for a coupling. We always slowed down when we got near the pipe now we just do it quickly. If we use this with our big vac trailer it's great but it can be used with out any vac to improve labor times. They don't sell a million of these a year so the cost is high $1800 for the basic unit new if you can find a used one snatch it up, but the 2k is really worth it after a few jobs. We use the air clay spade and the air knife to even out the sides of the trench walls to slide our shoring boards down so they are nice and even also.


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## gear junkie (Jun 20, 2008)

How long does it take to dig a hole like in the picture?


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## Cuda (Mar 16, 2009)

Not counting cutting the concrete, about 2 hours.


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## gear junkie (Jun 20, 2008)

That's with a mini exacvator?


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## Cuda (Mar 16, 2009)

No there was no access in the backyard, air knife, clay spade and 2 guys digging and one guy with a wheelbarrow and buckets. The air knife makes a perfect laser like cut so you can make the hole only as big as you need to which saves time. The hard clay turns to fluffy dirt because you hold the air knife right against the soil, the air goes in and pushes back at you making fluff you just have to get it out to the surface, if the hole had been bigger we would have brought the vac trailer.


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## gear junkie (Jun 20, 2008)

That's real quick...you standing over them wearing reflective sunglasses and a shotgun?


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## Cuda (Mar 16, 2009)

The whole thing has more time involved, 1 hour set up, 2 hours for cutting and breaking the area, add another hour picking stuff up at the yard, 2 hours on the hole. So a 6 hour day to get a 7 foot deep 3 wide 4 long hole to the sewer so we could burst in a line the next day. These people had the whole family flying in for Xmas and we needed to repair the sewer fast.


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## Cuda (Mar 16, 2009)

Here is a larger shot of the job. On the other side of the white fence is a set of entry stairs to the house, pipe had no bottom, the whole back of the house is a poured concrete patio, then the line came down to the sidewalk under the other stairs leading to the back yard and turned near the sidewalk, it was only 3-4 feet at the sidewalk so we made 2 holes and pulled a new line in. Pipe bursting was the best tool for the job, I can't even imagine breaking out so many stairs to put a line in the old fashion way.


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## plbgbiz (Aug 27, 2010)

We recently got an air knife. Awesome for around utilities. It won't cut anything but soil.


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## Cuda (Mar 16, 2009)

This is what I mean by set up lol.


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## Cuda (Mar 16, 2009)

Here is another use for the air knife. We needed to put in a new downspout tight line under concrete, didn't want to mole it and didn't want to cut the concrete and trench it so I tried tunneling today. Went real fast and made a nice clean hole for the new pipe.


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## JK949 (Mar 18, 2009)

Respect given!


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## johnlewismcleod (Apr 6, 2012)

Sweet tool! I'd never heard of or imagined an air knife existed :no:

Want much :yes:


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## plbgbiz (Aug 27, 2010)

Works great tunneling under a footing as well.


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## Richard Hilliard (Apr 10, 2010)

isn't that a little dangerous? where is the shoring?


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## johnlewismcleod (Apr 6, 2012)

Richard Hilliard said:


> isn't that a little dangerous? where is the shoring?


Right where it's supposed to be...first post, RH pic :laughing:


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## plbgbiz (Aug 27, 2010)

The brand name of ours is Soil Pick but basically the same as Cuda's Air Knife.


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## plbgbiz (Aug 27, 2010)

http://youtu.be/91jo4Q8_Snk


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## Pipe Rat (Apr 5, 2009)

OSHA would have a field day with that man in the hole over his head without shoring. You guys should be ashamed risking that mans life like that. Everyone goes home at night!!!!


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## tungsten plumb (Apr 15, 2010)

What size compressor do you need to run it?


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## plbgbiz (Aug 27, 2010)

tungsten plumb said:


> What size compressor do you need to run it?


It will work with a 185cfm tow-behind but it is sized to run best @220cfm.


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## tungsten plumb (Apr 15, 2010)

plbgbiz said:


> It will work with a 185cfm tow-behind but it is sized to run best @220cfm.


 Guess I wont be getting one of those then lol. it sure would be handy tho lol


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## plbgbiz (Aug 27, 2010)

tungsten plumb said:


> Guess I wont be getting one of those then lol. it sure would be handy tho lol


It can be awesome, but it can also be very inconvenient since we have to the rent the compressor.


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## Catlin987987 (Nov 12, 2010)

@ what PSI?


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## plbgbiz (Aug 27, 2010)

Catlin987987 said:


> @ what PSI?


90psi


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## Plumberman911 (Dec 23, 2012)

My old boss always told us in deep holes we were expendable and easily replaced. Had a few close calls. Once I cleaned around a main about 13 ft deep to use a banded saddle climbed out walked to my truck came back to saddle it the walls collapsed to leave about a 5 ft hole. That was close and I had the parts in the hole with me I'd been done.


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## johnlewismcleod (Apr 6, 2012)

Plumberman911 said:


> My old boss always told us in deep holes we were expendable and easily replaced. Had a few close calls. Once I cleaned around a main about 13 ft deep to use a banded saddle climbed out walked to my truck came back to saddle it the walls collapsed to leave about a 5 ft hole. That was close and I had the parts in the hole with me I'd been done.


Your old boss needs his arse kicked :blink:

Having said that, I've pushed the safety envelope many times before, but it was _my_ choice and _my_ arse on the line when I did...that's different.


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## Plumberman911 (Dec 23, 2012)

If there deep I go in them. I don't want someone else in there. Work quick and get out


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## johnlewismcleod (Apr 6, 2012)

Plumberman911 said:


> If there deep I go in them. I don't want someone else in there. Work quick and get out


There are a couple tricks for pushing the safety envelope. I made the mistake of posting one, but realized my mistake and deleted it.

The bottom line is we all need shoring below 6' and need to tie off extension ladders.

Do it...Charge the customer for it...Live to work another day. Our families depend on us.


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## plbgbiz (Aug 27, 2010)

I guess a lot of us have gone farther than we should from a safety stand point. I know I have.

I am much less inclined to push the risk for myself as I get older. I certainly do not want another man's blood on my hands.

We try to use hydraulic shoring to keep the holes small but sometimes the only choice is a big stair-stepped hole.


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