Well, if this current job is any indication, here's what needs to be done to ensure a painless pull:
First, for any long or complex run, consider 'going up' a conduit size.
Next, pay particular care to your transitions. Many folks 'stub up' in steel, and do the bulk of the underground run in PVC. The transition can be a real 'catcher' of mice and fish tapes .... why can't our transition fittings have a taper to them, like plumbing 'bells' do?
Buried PVC connections need primer as well as cement, and a wrap of duct tape isn't a bad idea. EMT connections definitely need to be wrapped, or otherwise sealed, on long runs. You want to keep water out, if you can. (On this job, we even had an overhead run fill with water!)
Tape itself doesn't seem to be enough to protect your stub-ups. Somehow, the tape gets torn and crud dropped in. Deliberate malice or just Murphy's law? I don't know- but next time I might try attaching a soft foam plug to the pull string, just inside the pipe, at either end.
Protect your threads on stub-ups with couplings and proper pipe plugs.
This job has also shown a real need to brace the **** out of the stub-ups, to preserve their alignment during the pour, etc. This means I'll be burying some strut, running the conduit within rigid sleeves, or taking other additional measures.
Your vacuum need not be large. You don't need a big tank or a high-horsepower motor. Ironically, on this job we had a little 1-gallon Shop-Vac out-pull a 5-hp, 10-gal heavy duty vac. It's not so much the pressure you need, as the air volume .... remember, NO vacuum can create more than about a 14-psi suction.
Which, of course, brings up the condition of the vacuum. There's an argument to be made for using a dedicated vacuum ... and, in any event, to protect the vacuum with the best filter you can get. Vacuum performance is dramatically affected by even a microscopic amount of wear on the impeller ... and drywall dust is instant death to blower performance.
I spent about $15 on a "micro cleaning" kit that provided me with various attachments. With a modest amount of tape, I can now reach into conduit, even when it's off to the side of a mud ring, and get a good seal. I'm essentially duplicating the big Greenlee fitting- but in a smaller, more maneuverable size. Plus, the mouse won't get sucked into the vacuum; instead, it sticks onto the end of the nozzle.
Ironically, the $21 bucket-top vacuum seems to best fill the bill. Heck, you can even find 3- and 4-gallon buckets to mount the top onto, making it much more ladder-friendly. The 1-1/4" hose seems to move plenty of air. Best of all, you can store the hose, etc., in the bucket between uses.
(Full disclosure here: I'm now working with a trade tool manufacturer to develop a vacuum targeted to our needs- for less than a car payment, let alone the cost of the whole car!)
This job has been a wire-pulling nightmare. I have two pipes, full of wire, that had to be abandoned. For both, we got the wire about 90% through before it stuck, and could not be pulled out. Think: 5000 ft. of #10 wire lost. Sort of puts the cost of PVC primer and duct tape in perspective.
