Uni-Mould Coupling Coat

Uni-Mould Coupling Coat is part of the Uni-Mould universal mould making system and should be used in conjunction with Uni-Mould Tooling Gel Coat and Uni-Mould Tooling Resin to produce hard-wearing, polishable moulds of any size with zero shrinkage suitable for use in just about any composites process.

Uni-Mould Coupling Coat is a vinylester laminating resin.

Requires MEKP catalyst (not included)

Suggested Purchasing Quantities

Use the table below to help you purchase suitable quantities of the resins and glass for a given mould size.

For full details on the Uni-Mould system, read our Uni-Mould Introduction and Application Guide.

Further Information

Application

The Uni-Mould Coupling Coat is designed to eliminate print-through of the mould reinforcement, to reduce the risk of blisters underneath the gel coat by ensuring the gel is reinforced with a skin of resin and glass and to provide an ideal substrate for the main reinforcement.

Uni-Mould Coupling Coat should be catalysed with standard MEKP catalyst (not included) at 1.5 - 2%. Apply a layer of the coupling coat over the mould surface and then two layers of 100g chopped strand mat . We do not recommend the use of glass surface tissue in lieu of the 2 layers of 100g CSM.

Wet out the CSM thoroughly with the coupling coat resin and ensure that all air is removed from the reinforcement, that it is well wetted through and that the reinforcement is conforming to all the contours of the mould, particularly any tight corners.

Uni-Mould Tooling Coupling Coat should applied to cured Uni-Mould Tooling Gel Coat and then be reinforced with Uni-Mould Tooling Resin as per the guidelines for those products.

Use with Prepregs

Although it is possible to use Uni-Mould moulds with out-of-autoclave (oven cure) prepregs (such as XPREG® XC110) we no longer recommend Uni-Mould moulds for this purpose.

Instead – for prepreg use – better results will be achieved using high temperature epoxy moulds made using our EG160 / EMP160 tooling system or XPREG® XT135 Tooling Prepreg. These high temperature epoxy tooling systems allow the prepreg to be cured at the optimum 120°C which reduces the cure time and improves the mechanical properties of the component. Additionally, epoxy tools have been found to result in a better surface finish with prepregs such as XPREG® XC110.

Key Processing Information

• Ease of Use
• Suitable for professional and hobby use (follow SDS advice).

• Odour
• Coupling Coat has a strong styrene based odour.

• Safety Precautions
• Wear gloves and goggles and work in a well ventilated area. Always read the SDS before use.

• Ambient Conditions
• Can be used from 15 to 30°C although pot-life and cure time will be affected significantly. Recommended working at an ambient of 20-25°C.

• Degassing
• Not necessary in most cases. Simply mix and use.

• Mix Ratio
• Add MEKP Catalyst at a ratio of 1.5 - 2%. Use digital scales.

• Mixing
• Mix thoroughly by hand for at around 2 minutes.

• Application
• Can be applied by brush. Apply over mould surface with 2 layers of 100g CSM.

• Pot-Life
• The pot life at 25°C is 15 - 20 minutes. Be sure to use your resin before this time.

• Exotherm (Over-Heating)
• Resin will heat-up whilst it cures. Mix in small batches and use expediently. Mixed resin in a pot will quickly overheat (exotherm) and can smoke/ignite. Never leave mixed resin unattended.

• Cure Time/Demould<
• You can back up with Tooling Resin as soon as the Coupling Coat has Gelled. Typically this can take 1.5 - 3 hours depending on temperature and MEKP ratio.

• Maximum Service Temperature
• When fully cured and post cured, the maximum Service Temerpature of Uni-Mould moulds is 90°C

• Overcoating / Second coatings
• Coupling Coat is normally applied in one session with 2 layers of 100g CSM.

• Shelf Life
• Uni-Mould Coupling coat has a shelf-life of 3 months.