How to Repair Powercrete Coatings
This document is designed to offer a procedure how how to make repairs to Powercrete field joint coatings. If you are instead looking for information detailing how to make a repair to Powercrete-DD, I would advise you to contact the pipe coater who applied the DD. That will be your best source.
When evaluating coating repair options for Powercrete field joint coatings (which may be Powercrete J, Powercrete R65/F1 or Powercrete R95), the starting point is always: "how much damage is there?"
In this specific article we are recommending that Powercrete R65/F1 50ml cartridges, Powercrete R95 50ml cartridges or hand applied kits of Powercrete J 2#, Powercrete R65/F1 1# or Powercrete R95 2# kits be used. Powercrete products are the best choice for repairing Powercrete coatings.
Detail Conditions of Coating Damage
#1: Defects 2.5" in diameter and less (including a pin hole)
#2: Defects larger than 2.5" in diameter
To Repair Damage Less than 2.5" OD (#1)
For repairing Powercrete Coatings (Powercrete J, Powercrete R65/F1 or Powercrete R95) that are minor, use the following procedure: Clean any bare metal showing with a wire brush to obtain a clean metal surface. DO NOT REMOVE THE SURFACE PROFILE. For adjacent (undamaged) Powercrete, use light sandpaper (60-80 grit) to clean the epoxy surface. Then wipe the surface clean with solvent to remove dust, dirt, grit, sandpaper residue, etc. Apply the Powercrete J, Powercrete R65/F1 or Powercrete R95 repair material (talk with JSI customer service to determine most efficient size for your needs) to coat the damage area and adjacent not-damaged area by at least 1" in every direction. Use a trowel or brush to spread the applied Powercrete repair material over the previously prepared surface. Insure the Powercrete coating is smooth and the coating thickness is equal to the applied coating thickness outside of this impacted area. Allow sufficient time for the repair area to cure and then evaluate that coating just as you evaluate the field joint coating area. Allow sufficient cure time and then follow the procedure set forth by the end user in their specification (in terms of potential hardness testing, holiday testing, etc). If holiday testing, 125 volts per mil is appropriate. If necessary, record the defect and repair procedure in the construction journal.
To Repair Damage Greater than 2.5" OD (#2)
First thing to do in cases of larger damaged areas: contractor must determine from the end user coating and construction specification if defects in the FJC of this size are allowed to be repaired, or if the coating must be removed and re applied. If the end user specification allows the Powercrete product to be repaired, use a one or two pound kit to perform the repair using the same installation steps as listed above under the #1 category.