Picked up a couple of Greenlee Blower Power Fishing System/Vacuum at the local auction. They were only $20 each and I figured they might be good for blowing the pull string through the 300′ of underground conduit I will be running to my shop and my house. The question is: what type of ball, badminton bird, whatever, is best to tie onto the string to avoid getting it stuck about halfway up the conduit? How good is the Greenlee thing as a vacuum?
Use these assembly techniques when installing crown risers and molding to minimize visible gaps and nail holes.
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial NowGet instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
Replies
I'll just toss out a few things here.
At $20 each, you've got a really good deal since Greenlee stuff is expensive. Unless the units are decrepit and broken.
I think the term is a "mouse". Check the Greenlee site. It's made of soft foam rubber the diameter+ of the conduit and has a plastic disk at each end and a wire trru the middle with a little loop on each side.
Get yourself some "fly line" or "jet line". This is amazingly strong fiberglass string of blue-white/ or green/white. The green/white is used for data and the blue/white is for power. It's the same stuff but you maise well be orthodox and follow the rules.
Most electrical contractors get the biggest, bulkiest, cheapest wet/dry vacuum from Rigis and concoct an assembly with cut off soda bottles and duct tape. For the "mouse" they use a puffed up plastic sandwich bag or a properly crumpled up wad of paper.
It is very important to follow the protocall religously because if you use green/white jet line, then you will be pulling in data cables.
~Peter
Everyone is entitled to my opinion. Except me.
In a lot of cases the cheapest, free, 'mouse' is a simple plastic grocery bag. You can use commercial 'mice' but these bags are as good, if not better, than the more expensive versions. For pull lines I usually use the poly line that comes in a 1500' box, loosely wound cheap stuff commonly seen at the big box for one-way tie downs. You could use mason's line on shorter runs but it will stretch and may cut into bends in PVC conduit on longer runs.
Tie the tag end of the line sticking out of the box to the loops, handles on a common plastic grocery bag. A full bag works for 2 to 6" conduit. Smaller conduits will work better with just a corner. Idea is to create a parachute that fills with air behind it and seals the conduit. No need to get fancy. Grab the bag corner and cut with a knife at about 8". Grab part of the cut edge and twist it a bit and fold over. Use this as the bend in a sheet bend.
It is a good idea to flip the hoses around and blow the run free of water. This prevents drowning the vacuum. If you want to 'train' a green helper tell him to get in the manhole and watch. Once moving, you have to maintain aseal on the blowing side for a few seconds as pressure builds up. the stagnant water from a 300' run of 2" comes out like a fire hose. Cheap fun.
Once clear Get someone on the other end with a vacuum and suck the bag into the run. Maintain a little friction on the line to keep the chute filled and pulling. Once the pull line is in small communication lines going into large conduits can be pulled in with the light line. Larger conductors need heavier pull ropes.
Once used it seldom pays to try to reuse this cheap line unless you have parallel runs where it can be laid out flat. If you have to wind it up it is better to use another run from the box.
Avoid nylon as it can stretch if the cable binds and suddenly let go with great force. Often this is just getting a hand jammed into a 2" conduit, a couple of jammed or broken fingers, but it can get much worse.
I only did this twice. Two 75 ft runs of 3/4". I used a sandwich baggy for the mouse.
I figured that I would have to mess with this a dozen times to get it to work.
But stuffed the mouse in one end, cupped the suction hose over the other and before I could even move my hands around to get a good seal the mouse was there.
Neat trick.Kevin Halliburton
"I believe that architecture is a pragmatic art. To become art it must be built on a foundation of necessity." - I.M. Pei -
Those ultra-thin grocery bags, the ones that a can of beans falls through, with the integrated hand holes work really well.
They also work pretty well for making icing cones for mortar mix, drywall mud or roofing tar. Pack a few scoops into a corner, roll tight and clip the corner. Makes controlled application much easier. Keep another handy and you can toss the remaining mess into it. Keeps the tar from going everywhere.
Casey,
I recently moved my business into to new building and had to fish cat 6 phone lines through about 350 ft of 1" pvc. We just used a shop vac, colored nylon layout twine from Home Depot and a plastic bag for the mouse. Worked like a champ ! The guy in the unit next to us paid the phone company $400 to do the same thing !
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
Did you hear about that hazard of sucking fumes from the pvc glue in the vac & causing a explosion?
Sounds like a good reason to blow before you suck.
This is a family forum so lets keep all this above board.
Then let me rephrase, another good reason to blow before you vacuum. Gets water/trash and fumes out.