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About Opti-tec 5012 Low Viscosity, Clear Epoxy Adhesive / Encapsulant

Opti-tec 5012 is a two component, low viscosity epoxy with very high optical clarity. It has a long pot life and can be cured at room temperature or at 80°C for 90 minutes. Opti-tec 5012 is designed for potting, encapsulation and adhesion of components where high optical clarity, good wetting and low viscosity are important.

Opti-tec 5012 can be used for bonding glass, quartz, metal and many plastics. It finds uses in assembly and repair of glass items where a clear adhesive is required.

Features & Benefits

  • High optical clarity, water white with excellent resistance to yellowing
  • Excellent transmission down to 300 nm
  • Low viscosity (500 cps)
  • Long pot life
  • Cures within 48 hours at room temperature. Cure can be achieved in 90 minutes at 80°C.
  • Opti-tec 5012 has high surface energy. This and its low viscosity allows it to readily wet and wick between surfaces. It develops strong adhesion to most materials used in optics, including metals, ceramics, glass and most plastics.
  • Good impact and thermal shock resistance, with low internal stresses due to low shrinkage on cure
  • Opti-tec 5012 is a hard, glass-like material after cure and can be polished
  • Good chemical and moisture resistance with a very low exotherm, suitable for sensitive potting and encapsulation applications
  • Opti-tec 5012 features low fluorescence


  • Optical assembly, optical filters, lenses, prismsOpti-tec 5012 low viscosity, clear epoxy used for bonding glass in art applications. Pier Box with Blue Gold Insert is by Tessa Clegg.
  • Glass bonding
  • Plastic & glass fibre optics
  • Opto-electronics, photonics, LED
  • Optical encapsulation & glob topping, casting, potting
  • Repair of glass, wood, ceramic
  • Potting or encapsulation where high optical clarity is required: geology samples, relics and artefacts, tissue samples


Typical properties    
Mix ratio 100:35 resin to hardener
Mixed viscosity 0.5-1.0 Pa.s (500-1000 cps) @ 25°C
Colour Water white
Specific gravity 1.05
Pot life @ 23°C 4 hours (< 25g mix)
8 hours (< 4g mix)
Max suggested mix 100 grams
Cure schedule Bondline temperature
48 hours
90 mins
Note: Optimal cured properties are achieved by curing at a bondline temperature of 80°C.
Cured properties
(90 minutes @ 80°C)
Glass transition temperature (Tg) 70°C
Hardness, Shore D 82
Temperature range -60 to 200°C
CTE 50-60 ppm/°C
Lap shear strength (Al/Al) 3000 N
Optical transmission >97% @ 300-900 nm; excellent to 2500 nm
Refractive index 1.56 est.
Dielectric strength 20kV/mm est.
Dielectric constant 3.1 est.
Volume resistivity >1014 est.
Shelf life 12 months in original sealed containers

Opti-tec 4200, 7020, 5012 transmission
Optical transmission of Opti-tec 4200, Opti-tec 7020, Opti-tec 5012


Safety Data Sheets
For the latest SDS for this product, please e-mail msds@intertronics.co.uk

Other Information

Technical Guide - Adhesive Problem? What's the Cure? Adhesive Problem? What’s the Cure?

A guide to adhesive bonding, considering structural bonding and the criteria involved for successful assembly.

All Downloads

Filename Size Download
Twinpack Mixing Instructions 0.17MB
Bulk Mixing Materials Instructions 0.21MB
Adhesive Problem? Whats the Cure? 0.36MB

Ordering Information

Opti-tec 5012 is available in twinpacks or in bulk.

Twinpack packaging

The twinpack is a clear film sachet, with the resin and hardener separated by a removable clip and rail divider. Click here for twinpack mixing instructions.

Standard twinpack size is 4g total weight. Opti-tec 5012 twinpack sachets are packaged in quantities of 5, sealed into a protective aluminium foil pouch.

Part number Description
OPT5012-4G 5 x 4g twinpack sachets
OPT5012-500G 500g kit (approx 1.1lbs)

Storage: Store in the original unopened containers under cool dry conditions between 15° and 25°C.


Next Steps

Our technical team are on hand to discuss your application requirements. Click here to get in touch.

Find out more information on how to purchase.

  • Last updated: July 2021
  • Version: 4.9

Statements, technical information and recommendations contained herein are based on tests we believe to be reliable but they are not to be construed in any manner as warrantees expressed or implied. The user shall determine the suitability of the product for his intended use and the user assumes all risk and liability whatsoever in connection therewith.