ARALDITE® AV 138M-1 / HARDENER HV 998-1

• Excellent chemical resistance
• Temperature resistant to 140°C
• Thixotropic, gap filling paste

Pretreatment

The strength and durability of a bonded joint are dependent on proper treatment of the surfaces to be bonded. At the very least, joint surfaces should be cleaned with a good degreasing agent such as acetone or other proprie- tary degreasing agents in order to remove all traces of oil, grease and dirt. Low grade alcohol, gasoline (petrol) or paint thinners should never be used. The strongest and most durable joints are obtained by either mechanically abrading or chemically etching (“pick- ling”) the degreased surfaces. Abrading should be followed by a second degreasing treatment

Resin and hardener should be blended until they form a homogeneous mix.

Application of adhesive

The resin/hardener mix is applied with a spatula, to the pretreated and dry joint surfaces. A layer of adhesive 0.05 to 0.10 mm thick will normally impart the greatest lap shear strength to the joint. The joint components should be assembled and clamped as soon as the adhesive has been applied. An even contact pressure throughout the joint area will ensure optimum cure.

Mechanical processing

Specialist firms have developed metering, mixing and spreading equipment that enables the bulk processing of adhesive. We will be pleased to advise customers on the choice of equipment for their particular needs.

Equipment maintenance

All tools should be cleaned with hot water and soap before adhesives residues have had time to cure. The removal of cured residues is a difficult and time-consuming operation.If solvents such as acetone are used for cleaning, operatives should take the appropriate precautions and, in addition, avoid skin and eye contact.

Typical times to minimum shear strength

Average lap shear strengths of typical metal-to-metal joints (ISO 4587) (typical average values)
Cure: 16 hours at 40°C and test at 23°C
Pretreatment - Sand blasting

Average lap shear strengths of typical plastic-to-plastic joints (ISO 4587) (typical average values)
Cure: 16 hours at 40°C and test at 23°C
Pretreatment – abrading with sand paper and degrease with isopropanol

Lap shear strength versus temperature (ISO 4587) (typical average values)
Cure: 16 hours at 40°C

Shore hardness (typical average value) -  D86

Tensile Properties (ISO 527) (typical average values)
Cure 16 hours/ 40°C , tested at 23°C
Tensile strength - 29 MPa
Tensile modulus - 4.2 GPa
Elongation at break - 0.8%

Lap shear strength versus immersion in various media (typical average values)
Unless otherwise stated, L.S.S. was determined after immersion for 30, 60 and 90 days at 23°C. Cure: 16 hours at 40°C

Lap shear strength versus tropical weathering (typical average values)
(40°C/ 92% Relative Humidity) On aluminium. Cured for 16 hours at 40°C and tested at 23°C. Pretreatment - Sand blasting

• Araldite AV 138M-1 and Hardener HV 998-1 must be stored at room temperature provided the components are stored in sealed containers. The expiry date is indicated on the label.
• These products are generally quite harmless to handle provided that certain precautions normally taken when handling chemicals are observed. The uncured materials must not, for instance, be allowed to come into contact with foodstuffs or food utensils, and measures should be taken to prevent the uncured materials from coming in contact with the skin, since people with particularly sensitive skin may be affected. The wearing of impervious rubber or plastic gloves will normally be necessary; likewise the use of eye protection. The skin should be thoroughly cleansed at the end of each working period by washing with soap and warm water. The use of solvents is to be avoided. Disposable paper - not cloth towels - should be used to dry the skin. Adequate ventilation of the working area is recommended.