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Scubapoxy 3725
Fast-cure Underwater-applied Adhesive

A Kevlar®-reinforced, two-pack epoxy designed as a specialist fast-cure adhesive for underwater, marine and wet-area environments.

Quality materials are used with Kevlar® fibres to create a high-strength, high-performance adhesive that provides genuine underwater capability and a rapid 5-minute cure.

Scubapoxy 3725 was also formulated in conjunction with commercial divers to be as diver-friendly as possible. The fibre-reinforced, thixotropic nature of the product is not prone to stringing or floating, while the resin-rich, paste-like viscosity gives superior tackiness and adhesion compared to traditional “putty” products.


The filter box area in a swimming pool where the vertical tiles were re-attached using Scubapoxy 3725.  Common uses for Scubapoxy 3725 include:

Tanks, Reservoirs, Pools, Piers, Pontoons, Splashzones, Wet Areas, Wastewater, Oil/Gas Pipelines,
Boats & Vessels, Marine Structures, Hydroelectricity

Product Details

Type: Two-pack epoxy - solvent-free/100% solids. 
Colour: Mid-grey. 
Finish: Gloss (subtle orange peel texture).
Mix Ratio: 1:1 v:v 
Pack Size: 4 litres. 


  • Proven performance in underwater applications.
  • Cures hard in 5 minutes.
  • Paste-like, diver-friendly formulation.
  • Easy 1:1 by volume mix.
  • High-build, gap-filling properties (including vertically).
  • Use for patching, sealing and attaching.
  • Reinforced for greater film strength and cohesion.
  • Good overall chemical resistance.
  • Excellent adhesion to concrete, steel, fibreglass etc.
  • Not a Dangerous Good for quicker, easier shipping.

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ASTM D-2280  JIS K 5600-5-4:1999
81-86 Shore D.

Chemical Resistance

Scubapoxy 3725 is resistant to exposure from all common liquids in residential, commercial, industrial and marine applications, e.g. chlorinated water, saltwater, wastewater, cleaners, dilute acids/alkalis etc.

Staining may occur when exposed to aggressive chemicals. Good housekeeping practices, including dilution and spillage clean up, will minimise chemical damage. For full immersion performance, contact supplier.


The actual coverage achieved by Scubapoxy 3115 will depend on the application type, as well as substrate characteristics and condition.

The theoretical yield for an application where the product is applied at an average of 5mm is: 4 litre kit @ 0.2m2/L = 0.8m2

A 4 litre kit of Scubapoxy 3725 underwater-applied fast-cure adhesive.

Curing Times

 Time (@ 25°C) 

Pot Life - 4 minutes 
Set (touch) - 5 minutes 
Set (hard) - 10 minutes 
Re-coat (min.) - N/A 
Re-coat (max.) - N/A 
Full Cure - 12 hours  

Approximate time frames for full kit @ 25°C. Pot life will shorten for larger mixes. Curing times will decrease with increasing temperature (+10°C will halve curing times, -10°C will double them). 

Product Notes

  • Scubapoxy 3725 is very effective when used with bandage or fibreglass tape to plug leaks. Mix enough to saturate the bandage or tape, butter on as you wrap. For full details, contact supplier.
  • If left exposed to the air for long periods of time, Part B of Scubapoxy 3725 can form a “skin” typical of the hardener used. While this can be removed and the remainder of the product underneath used, every effort should be made to ensure containers are sealed properly.
  • Scubapoxy 3725 may be difficult to apply at temperatures below 15oC. In this case, it’s helpful to pre-warm the components separately in a heat bath before use.
  • Scubapoxy 3725 has thixotropic properties, which give the wet film good sag resistance on vertical surfaces. Thickness should not exceed 2000 microns/2mm when applied at temperatures greater than 25oC.
  • Consistent with all epoxies, Scubapoxy 3725 will tend to discolour upon extended UV exposure. This doesn’t detract from coating performance.
  • Clean up with MEK, acetone or methylated spirits.

Surface Preparation


Sound surfaces should be well cleaned by high-pressure water/abrasive blasting if possible. Small areas can be cleaned by grinder; not practical for large areas.

In general, ensure surfaces are clean and free from oils, grease and loose contaminants. Lightly abrade with sandpaper if above options aren’t available, and use methylated spirits to clean the surface once more before application.


High-pressure water-blasting or abrasive blasting to class 2.4 (AS 1627.4) with a typical profile of 50-70 microns in a jagged pattern. Grinding acceptable for small areas. Can be applied over tight rust. For best results, clean metal surface with a sponge soaked in detergent (sealed in a locked plastic bag if working at depth) immediately before application.

Coated Surfaces: 

Can be applied over existing, well-adhered, abraded, clean coatings.


  • Caution - Surface must be prepared and everything completely ready for application before mixing Scubapoxy 3725 otherwise it could harden before use.
  • As a minimum in underwater applications, preparation should remove all loose surface contamination and marine growth around the site using an abrasive paper or pad, wire brush etc.
  • Application should begin within 30 minutes of preparation to avoid re-settling on the surface. If delay is longer than 30 minutes, repeat preparation.


For full safety instructions, consult SDS. Wear protective clothing, goggles and gloves to prevent skin and eye contact.

NOTE: Check packaging for correct components before mixing.

Mix product at a ratio of 1:1 by volume with a drill mixer.

Only work with small volumes (less than 500mL) to avoid excessive heat generation and product hardening before use.

Pour/scrape Part B into Part A and mix with a stiff spatula or similar instrument until a consistent colour is obtained, scraping sides at least once to ensure all product is taken in.



“Butter” the adhesive on the entire repair site. If adhering two surfaces, “butter” both surfaces and press gently together to create the bond, making sure some product is left in the joint.

If applying underwater, let sit for a moment then work/smear slowly to allow the product to displace the water and “wet” the surface. When attaching material underwater, it’s best to smear the product above water first and then take it below to fix in place.


Keep containers closed when not in use. Store below 40°C. Do not store in direct sunlight. Shelf life is at least 12 months in original, unopened container. Seek advice from your local council regarding accepted disposal methods.

First Aid

CAUTION: KEEP OUT OF REACH OF CHILDREN.  IF ON SKIN: Remove immediately all contaminated clothing. Rinse skin with water. IF IN EYES: Rinse cautiously with water for several minutes. Immediately call a POISON CENTRE (Australia - 13 11 26) or doctor/physician. If skin irritation occurs: Get medical advice/attention. 

WARRANTY DISCLAIMER: The technical data given herein has been compiled for your help and guidance and is based upon our experience and knowledge. However as we have no control over the use to which this information is put, no warranty express or implied is intended or given. We assume no responsibility whatsoever for coverage, performance or damages, including injuries resulting from use of this information or of products recommended herein.

Download copy of this technical data sheet (TDS) - Scubapoxy 3725

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