Question: How do I repair damage to a PE factory applied coating?
Answer: We have several options; all are dependent upon the size and scope of the damage. I will break it down as follows:
For very minor damage, we offer what we call a Perp Melt Stick. This is a stick of hot melt adhesive supplied in the form of a cylinder, 1" diameter by 12" long. Using a propane torch, the melt stick is heated and the adhesive flows down to fill and cover the area of minor damage. This is very similar to (but larger than) the commonly used FBE repair sticks that most people are familiar with. This product is sold by the stick and is always in stock and ready to ship at Joint Specialists.
Perp, which stands for Poly Ethylene Repair Patch is a cross-linked, but not expanded product. This means that it doesn't shrink. Perp is sold as a roll of material and patches are cut in the field for specific sizes of damage. As an example, if you have a 2" square damaged area; you would cut a piece of Perp at least 6" x 6" in order to have 2" of overlap on all sides for the proper seal to be made.
In addition, Perp Filler is sold as a roll of mastic material and is used to rebuild the damaged area so that there is a flat surface to bond the Perp patch to. This also helps avoid any entrapped air in the repair.
For three layer repair requirements, a layer of S1301M epoxy primer can always be used as the initial coating (prior to applying Perp Filler and Perp Patch).
Answer: We have several options; all are dependent upon the size and scope of the damage. I will break it down as follows:
Pin Hole / Very Minor Damage
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| Perp Melt Stick in action, repairing minor damage |
Minor to Moderate Damage
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| In the center of the pipe, we see the installed Perp patch. |
In addition, Perp Filler is sold as a roll of mastic material and is used to rebuild the damaged area so that there is a flat surface to bond the Perp patch to. This also helps avoid any entrapped air in the repair.
For three layer repair requirements, a layer of S1301M epoxy primer can always be used as the initial coating (prior to applying Perp Filler and Perp Patch).
Major Damage
Lastly, for major damage, it is best to install a full encirclement shrink sleeve; chosen based upon the specific requirements of the pipeline (click HERE for more info). In such a case, we are essentially treating the major damage as another field joint; coating, sealing and encapsulating the area with a shrink sleeve (after proper cleaning, etc of course). 
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