Underwater Grade Epoxy

A solvent-free underwater grade epoxy compound. Supplied as a component kit.

  • Lining inside of damp concrete pipes (standard epoxies will not adhere). 
  • Underwater repair of ships’ hull coatings. 
  • Lining up-stream of concrete dams to stop seepage. 
  • Flooring – on wet floors – where dampness is a result of water applied on surface (not rising dampness), e.g. dairies, abattoirs and other environments. 
  • Underwater grouting or patching. May be used as a grout with graded silica sand. Mixing ratio 3:1 by volume of sand and epoxy resin. 
  • May be applied as a paint by roller or brush underwater
  • Serves as a paint (roller or brush) 
  • Serves for grouting 
  • Underwater working 
  • Easy to work, gloss finish
Surface Preparation

All surfaces must be clean and sound. Also see our Technical data sheet “Preparation of Surfaces”.


Self bonding.


Thoroughly mix the contents of the two containers together before use. Should the kit be split, a mixing ratio 1:1 by WEIGHT ONLY must be used. If silica sand extended epidermix 311 is used as a grout, a mixing ratio 3:1 by volume of sand and epoxy resin is advised. In this application, the resin / activator blend should be transferred to a clean, dry container of suitable size, which has been thoroughly cleaned. Run the dry aggregate into the mixed resin and continue mixing until all the aggregate is wetted and a homogeneous mass is produced.

Properties of Wet Material

 Mix ratio 

1:1 by weight only 


1.055 g/cm3 

Colour: Base Clear Activator 

Clear straw yellow Mixed Clear light yellow 


Do not dilute 


Mobile Liquid 

Shelf Life 

2 years from date of manufacture 

Storage conditions 

Store under cover in cool conditions 


500ml and 5L kits 

Properties of Cured Material



Filled 1:3 Volumes Silica Sand 

Compressive strength @25°C 

56 MPa 

68 MPa 

Tensile split cube test @25°C 

10 MPa 

8 MPa 

Double lap shear strength 

9 MPa (direct clamp) 

5 MPa (2mm bond line) 

Grouting test: 15 diameter embedment 

12mm HT bar yielded & fractured in 19mm Ø steel pipe 

12mm HT bar pulled out of 25mm Ø steel pipe @ 7 MPa 

Modified Arizona shear test 

55 MPa prisms failed in concrete 

Max service temp 

Dry: 60°C Wet: 40°C 

Shrinkage during cure 


Chemical resistance 

Excellent towards aqueous media. Good resistance towards dilute alkali and mineral acids 

Solvent resistance 


Properties During Application

Application by 

Brush, short fibre roller and trowel for mortars 

Pot life 

45 – 60 min/500ml 

Volume solids 


Coverage (unfilled) 

1L/m2 will yield 1mm film thickness 

Coverage (filled) 

1L mixed epoxy liquid yields approx. 3L mortar when mixed 1:3 with abe® coarse No. 1 silica sand 

Curing time @25°C 

Touch dry:12 hrs Practical cure: 24 hrs Full cure: 7 days 

Over-coating time @25°C 

Min: 6 hrs Max: 48 hrs 

Application temp range 

10ºC to 40ºC 




epidermix 311 applies equally well underwater or above water. epidermix 311 bonds directly by displacing the water on a surface. epidermix 311 does not tend to emulsify or crawl when brush or rolled underwater, or on a damp surface. epidermix 311 hardens in 24 hours underwater at ambient of about 25°C. Good leveling, flow, gloss and flexibility is achieved. 

Note: epidermix 311 must always be used in such a way as to prevent moisture ingress. It may not be used to seal dampness into a surface. 


Clean equipment with abe® super brush cleaner, and then rinse with clean water.

Protection on Completion

Protect against UV if not permanently underwater. Most epoxies chalk and degrade in extensive sunlight. 

Model Specification

Two-component, solvent free underwater grade epoxy liquid. 

The underwater grade epoxy shall be epidermix 311, a two component, solvent free resin system applied in accordance with the manufacturer’s recommendations, a.b.e.® Construction Chemicals.

Health & Safety

Product safety information required for safe use is not included. Before handling, read product and safety data sheets and container labels for safe use, physical and health hazard information. The safety data sheet is available from your local a.b.e.® Construction Chemicals sales representative.

Important Note

This data sheet is issued as a guide to the use of the product(s) concerned. Whilst a.b.e.® Construction Chemicals endeavors to ensure that any advice, recommendation, specification or information is accurate and correct, the company cannot – because a.b.e.® has no direct or continuous control over where and how a.b.e.® products are applied – accept any liability either directly or indirectly arising from the use of a.b.e.® products, whether or not in accordance with any advice, specification, recommendation, or information given by the company.

Further Information

Where other products are to be used in conjunction with this material, the relevant technical data sheets should be consulted to determine total requirements. a.b.e.® Construction Chemicals has a wealth of technical and practical experience built up over years in the company’s pursuit of excellence in building and construction technology.