CCTV Inspection Before Lining or Coating is CRITICAL

This past week I got a video of a liner that had torn on installation. In the past I’ve gotten photos of calibration tube that was cut during installation and I’ve received video of coating jobs with material not covered poking out from the pipe surface. So, what goes?

Everyone knows that you clean pipe before lining or coating pipe. Failure to do so will end up giving you a lined or coated pipe that looks less than professional. The problem occurs when you look at a cleaned pipe in a general view with broad strokes. While the overall job looks like it’s ready to line or coat, the devil is in the detail. If the overall job looks good, you need to take a closer look at the detail. Things get dumped in sewers all the time. Some of those things catch is areas that make them hard to see, but if you look closely, they become clear. Sharp objects like razor blades, nails, screws, and broken glass often find their way into sewers. Those sharp little items may cause you to have a failure. In the cases I mentioned a sharp object sliced the liner as it was inverting. The sharp point remained in one place and sliced several feet of liner until it finally dislodged and no longer was a factor. So in the middle of the lined pipe there was a 15’ tear in the liner. If the sharp object were located in a different area no one may have ever known but in this case the rip was along the path that allowed the calibration tube to breach the liner and move to the outside of the liner between the host pipe and the rest of the liner. As it cured a fold where the excess material bunched up was visible for the 15’ then the pipe had half of the pipe lined while the other half was unlined as the calibration tube pushed the portion of the liner to the bottom half of the pipe while the upper half had no liner at all.

The next example of sharp items in the pipe that killed a calibration tube was a broken shard of clay pipe that had wedged itself in such as way as to score the calibration tube with a scratched through tear in the tube. Unable to hold air, the cal tube was unusable to cure the liner.

Finally, a piece of scale that was very difficult to see poked out from the surface of the pipe. After six coatis of poly urea, you could see the scale poking out of the surface of the coated pipe. Cast iron pipe, being black, and the scale being dark rusty color makes post cleaning inspection extra difficult due to the dark surfaces.

My point here is to review your post cleaning video with a more detailed eye that looks for issues that may cause you trouble in the future.

Pipe Lining Supply News:

  • Only a couple of weeks till The Water Expo in Miami. (Aug. 29-30 Booth 638)
  • Upcoming training and certification class in Springfield, MO in mid-October – Details of dates and where to sign up coming soon.
  • Success of coating 12” & 14” HVAC underfloor ducting. Galvanized pipe had rusted out and our Quik Coating process saved jack hammering a finished room in a lower level to rehabilitate the pipe.

Our 70CFM Air Compressor, the Con X Air Compressor is now in stock and ready to ship. Call us for details 888-354-6464 or