Glass Outerwrap, Protective Fiberglass Outerwrap by Denso

Protective coating with exceptional mechanical and impact strength for underwater, underground, and above-ground pipes and piles.
Denso Glass Outerwrap, Protective Fiberglass
Grouped product items
Product Name Qty
Glass Outerwrap, 3" x 9' Rolls, 15 Rolls/Case, by Denso
Glass Outerwrap, 4" x 30' Rolls, 5 Rolls/Case, by Denso


Denso Glass Outerwrap is a fiberglass cloth impregnated with a water activated resin that is used as a protective outer wrap over Denso Petrolatum Tape. Also used as a pipe repair tape.


A protective fiberglass coating which offers exceptional mechanical and impact strength for underwater, underground, and above ground pipe and pipelines.


  • Resists cold and hot temperatures
  • Easy to apply, no mixing or messy clean up
  • Resistant to water, acid, salts, or soil organics
  • Can be applied underwater or to wet surfaces
  • Minimal surface preparation required
  • Quick, long term protective coating, ready for immediate service
  • Contains no solvents



Prepare surfaces by removing all loose scale, rust or other foreign matter in accordance to SSPC SP2 “Hand Tool Cleaning” or SP3 “Power Tool Cleaning”. High pressure water wash of 3,000 - 7,000 psi is also suitable. Spirally wrap a layer of Denso Petrolatum Tape with a minimum 1" overlap. For severely corrosive environments, a 55% overlap is recommended. While wrapping, press air pockets out and smooth all lap seams. Using rubber gloves, remove the Denso Glass Outerwrap from the hermetically sealed foiled pouch and soak in temperate water (salt or fresh) for 20 to 30 seconds. Remove and begin wrapping tightly, overlapping a recommended 50%.

Irregular surfaces such as valves, flanges, etc. may require the use of Densyl
Mastic or Denso Profiling Mastic. Refer to the product sheets for these specific
products for information on application and selection.





Flexural Strength (ASTM D709-71)
Tensile Strength (ASTM D638)
Compression Strength (ASTM D695-77)
Dielectric Strength
Maximum Service Temperature
Setting Time at 70°F (21°C)

16,100 psi
24,900 psi
26,600 psi
16 kV
30 min

11.32 kgf/mm2
17.51 kgf/mm2
18.70 kgf/mm2
16 kV
30 min

Quantity Estimates

(All rolls are 33 feet in length)


Tape Width

Roll Length

Rolls per Case

Coverage with
50% Overlap


9 ft
30 ft
40 ft


17 ft2/case
25 ft2/case
40 ft2/case