CIPP Lateral Lining Tips! Welding TPU To Liner Material

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Be sure to see us at the WWETT Show in Indianapolis on February 22, 23, & 24th. Our demo schedule for the Quik Coating process will be 9:00AM, 11:30AM & 1:30PM in booth 6410 daily. We will demonstrate the Quik Shot(tm) CIPP lateral lining process at Lucas Oil Stadium attached to the Convention Center via underground walkway from the Convention Center. We will demo our self contained trailer with heat/AC, generator, wet out table, calibration roller, Quik Shot(tm), and storage as it is used in the field.

“I glue calibration tube for remote start liners for laterals, but sometimes the glue lets go and my attempt to use CIPP to line a lateral fails. Is there a better glue than the Rhino glue I’ve been using or another method?”

I know many of you have and are still using glue to start a CIPP liner at some other location than at the inversion device regardless of what kind of inversion device you are using. I also know that there are a fair amount of times that the glue doesn’t hold or that you got too much on the material and it won’t invert. I’ve talked to many installers that would like something more reliable than the glue and we found it after much R & D to perfect the process. If you weld on a like material to the coating of the liner, in other words polyurethane leader to polyurethane liner or PVC leader to PVC coated liner, you can form a great bond that will stay together and will invert without getting too hard at the connection.

There are a couple of ways to accomplish this method and either way works although one takes a little more practice than the other. Initially I tried a heat gun bringing the temperature on the liner/leader to about 400F for 12 to 15 seconds. This is where it gets tricky with this method. Your heat guns operate between 110F at just under 1,000F. Your job is to hold it far enough away from the material to achieve the 400F but close enough to get in that range and then trying to determine how long you’ve held 400F to complete the weld. If it’s not hot enough the weld won’t hold. If it’s too hot you’ll melt the material and leave holes that won’t hold vacuum or resin inside.

The second method is much more reliable and takes very little training. Use a flat iron, sold in every department and drug store to straighten hair, to accomplish the weld. Find one with temperature control and set to 400F. It will let you know when you reach the 400F mark. Using acetone, clean any surfaces to be welded together. Remove oil from your hands, printing on the materials, and other debris from handling by wetting a clean rag with acetone and scrubbing the surfaces. Once complete, slip the leader material over the liner. Usually the leader is a little larger than the liner and we’ll address that in a moment. Using a timer you will weld the top and bottom of about 1/2 of the liner/leader surface for 12 to 15 seconds. Flip the flat iron over to the other side and repeat the process. For the edges of the leader that are open and not welded closed, turn the flat iron 90 degrees to align with the liner and leader and weld the overlap closed. You now have a sealed liner to leader connection ready to invert.

What does all of this mean to you? The first thing is all of those scraps of liner from previous jobs you’ve saved wondering what to do with 11′ here and 14′ there. You can them together and make a longer line out of scrap materials, saving the expense of tossing them. We sometimes have turns and bends where we’d like to have a very flexible liner to go around the corners and would prefer a less stretchy material for the straight parts. You could weld together pieces of each to form your turns while using the less stretchy material to get closer to your mark you are attempting to hit.

If you have liner with holes in it for whatever reason, you could weld patches on the liner with cut pieces of the calibration tube.  If wetting out a very long liner and using multiple vacuums to extract air and impregnate the tube, you could patch the vacuum holes and cool the spot before the resin arrives  to keep your vacuum efforts intact without losing vacuum.

“Why can’t I just weld on my PVC calibration tube? I tried it and it seams to stick”. You can weld PVC calibration tube to PVC coated liner but if the liner is PU coated, it may not stick through the inversion. Because the materials are dissimilar materials, and they both have melt points, the bond may release during inversion. Further, the stitching on the higher temperature calibration tubes won’t stick at all, leaving an unsealed connection that won’t hold air or water.

Your next concern is “how do I get it to let go?” If a sharp jerk on the calibration tube doesn’t let it release, a 2 minute “sanding” with our reinstatement tool removes the bond with ease.

For more details, call 888-354-6464 for instructions and to order calibration tube material.

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