Downloads (3)

This is a chemical product. Before storage or use you must download and read the accompanying safety and technical datasheets.

Safety Data Sheet (SDS)373 KB
Dutch Safety DataSheet386 KB
Technical Datasheet (TDS)277 KB

Specification

Product Data
ColourClear
Chemistry / MaterialPolyester
Viscosity15000mPa.s
UV ResistanceVery Good
Volatile Content43%
Mechanical Properties
Max Service Temp76°C
Cured Mechanical Properties
Hardness80 (Hard)Shore D
Tensile Strength67MPa
Tensile Modulus3960GPa
Elongation at Break2.2%
Tg Onset (DMA)76°C
Pot Life and Cure Times
Pot Life (Typical)15mins
Initial Cure Time11Hrs
Full Cure Time7Days
Weight and Dimensions
Density1.11g/cm³
General Properties
Gross Weight1.212kg

Shipping Information

Restrictions

In the currently selected pack size, this product is classed as dangerous goods in limited quantity for the purposes of transport.

Shipping is possible to all UK addresses, including the Channel Islands, without restriction. However, due to being classed as 'dangerous goods', delivery times are not guaranteed on any delivery service.

Shipping to EU countries is now done through our European subsidiary based in the Netherlands. All EU customers should use www.easycomposites.eu.

To check availability of shipping to any other country, add the item to your basket and use the shipping calculator on the basket page.

For a full information regarding the shipment of dangerous goods to all destinations, see our delivery information page.

Package Size

There are no package size restrictions or surcharges for this product.

Delivery Cost

To find the availability and cost for delivery of this item to your address, add it to your basket and then use the instant shipping calculator on the basket page.

GC50 Epoxy Compatible Clear Polyester Gelcoat

GC50 is a clear, UV stable polyester gelcoat designed specifically for use with epoxy resin laminates. Unlike conventional polyester gelcoats, which epoxy resin cannot bond properly to, GC50 cures dry to the touch on the open face and can be fully bonded to by epoxy resin.

Requires MEKP catalyst, not included. Available to buy online in 1kg, 5kg and 25kg tins.


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AVAILABILITY:12 in stock available for immediate shipping


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PRICE
£20.20ex. VAT
(£20.20 /KG)
12 in stock available for immediate shipping
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PACKS
PACKS
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If you believe you’re buying an equivalent product cheaper elsewhere, contact us to discuss your requirements.

Easy Composites' GC50 Epoxy Compatible Gelcoat is a very special type of polyester gelcoat designed specifically for use with epoxy based wet-lay or resin infused laminates in place of an epoxy gelcoat or post-production paint/lacquer.

As a polyester-based gelcoat it brings the advantages over epoxy gelcoat of being highly polishable and offering excellent UV stability. What distinguishes GC50 from a conventional polyester gelcoat is its exceptional bond to epoxy laminates.

This fast curing gelcoat is ready for the application of the epoxy laminate, either by wet-lay or resin infusion, within 2-3hrs (@25°C) but also remains bondable for up to 24hrs making it easy to achieve optimum bond strength.

The gelcoat offers extremely good inter-laminate strength to a wide range of epoxies and has been tested and found fully compatible with the entire range of Easy Composites epoxy resin systems.

If you need a high quality clear Polyester Gelcoat for use with Polyester resins then we would recommend our CLEARPOL Extra Clear ISO NPG Polyester Gelcoat.

Advantages

When applied at the recommended 0.3mm - 0.4mm thickness GC50 exhibits excellent clarity making it ideally suited for use on carbon fibre parts where the clear epoxy gelcoat will provide an excellent gloss finish to the natural carbon fibre appearance.

The gelcoat can also be pigmented to any colour using standard polyester pigment pastes where its excellent UV resistance will ensure colours stay glossy and do not fade.

Our GC50 Epoxy Compatible Polyester Gelcoat has been developed to offer extremely good UV resistance with 12-month sun exposure testing showing very low colour change and excellent gloss retention. This UV protection is especially useful for epoxy based laminates which are otherwise vulnerable to UV damage.

How to Buy

The GC50 resin is available in 3 different pack sizes: 1kg, 5kg and 25kg. Please choose the pack size required from the drop-down list at the top of the page.

Requires MEKP catalyst, not included.

Further Information

How to Apply

The epoxy compatible gelcoat is very easy to use. It is catalysed using standard MEKP catalyst (sold separately) and can then be sprayed or applied by brush.

After 2-3hrs the gelcoat is ready to be 'backed-up' with the epoxy resin based laminate which can be by wet-lay or resin infusion. For resin infusion the slight tack of the gelcoat can be very helpful in the positioning of carbon fibre or other reinforcements into the mould.

Once the laminate is cured the part can be de-moulded and is ready for use; no further treatment is needed and the part will have a highly polishable, glossy, UV stable gelcoat with an incredible, proven bond to the epoxy part.

Compatibility Information - Dos and Don'ts

Although by no means an exhaustive list, the mould materials, pigments and additives listed below have all been tested and are known to work well with GC50.

Compatible Moulds

  • Uni-Mould Mould System
  • Epoxy Tooling Gelcoat
  • Epoxy gelcoat based moulds
  • Polypropylene and polyethylene sheet
  • Aluminium
  • Toughened Glass (eg. flat sheet manufacture)

Compatible Pigments

  • Polyester Colour Pigment * (for vivid opaque colours)
  • Translucent Tinting Pigment * (for less vivid opaque colours)

Compatible Fillers

  • All dry filler powders**

* With bold coloured laminates such as carbon fibre, the underlying colour of the fabric may still show through the pigmented resin, especially with thinner layers of resin over the underlying laminate.

** Although technically compatible, very few occasions would warrant the use of filler powders with a clear gelcoat. Adding filler powders will in most cases negatively effect the clarity of the resin.

Key Processing Information

  • Ease of Use: Suitable for professional and hobby use (follow SDS advice).
  • Odour: GC50 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 2%. Use digital scales.
  • Mixing: Mix thoroughly by hand for at around 2 minutes.
  • Application: Can be applied by Gelcoat spray cup gun or by brush. Maximum thickness 0.8mm.
  • Pot-Life: The pot life at 25°C is 12 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: At 25°C you can expect the gelcoat to be ready to be backed up in around 2-3 hours. The Gelcoat remains bondable for up to 24 hours.
  • Overcoating / Second coatings: Do NOT attempt to 'double gel' as GC50 will NOT bond to itself leading to delamination.
  • Shelf Life: The shelf life is 5 months from date of manufacture.

Easy Composites' GC50 Epoxy Compatible Gelcoat is a very special type of polyester gelcoat designed specifically for use with epoxy based wet-lay or resin infused laminates in place of an epoxy gelcoat or post-production paint/lacquer.

As a polyester-based gelcoat it brings the advantages over epoxy gelcoat of being highly polishable and offering excellent UV stability. What distinguishes GC50 from a conventional polyester gelcoat is its exceptional bond to epoxy laminates.

This fast curing gelcoat is ready for the application of the epoxy laminate, either by wet-lay or resin infusion, within 2-3hrs (@25°C) but also remains bondable for up to 24hrs making it easy to achieve optimum bond strength.

The gelcoat offers extremely good inter-laminate strength to a wide range of epoxies and has been tested and found fully compatible with the entire range of Easy Composites epoxy resin systems.

If you need a high quality clear Polyester Gelcoat for use with Polyester resins then we would recommend our CLEARPOL Extra Clear ISO NPG Polyester Gelcoat.

Advantages

When applied at the recommended 0.3mm - 0.4mm thickness GC50 exhibits excellent clarity making it ideally suited for use on carbon fibre parts where the clear epoxy gelcoat will provide an excellent gloss finish to the natural carbon fibre appearance.

The gelcoat can also be pigmented to any colour using standard polyester pigment pastes where its excellent UV resistance will ensure colours stay glossy and do not fade.

Our GC50 Epoxy Compatible Polyester Gelcoat has been developed to offer extremely good UV resistance with 12-month sun exposure testing showing very low colour change and excellent gloss retention. This UV protection is especially useful for epoxy based laminates which are otherwise vulnerable to UV damage.

How to Buy

The GC50 resin is available in 3 different pack sizes: 1kg, 5kg and 25kg. Please choose the pack size required from the drop-down list at the top of the page.

Requires MEKP catalyst, not included.

Further Information

How to Apply

The epoxy compatible gelcoat is very easy to use. It is catalysed using standard MEKP catalyst (sold separately) and can then be sprayed or applied by brush.

After 2-3hrs the gelcoat is ready to be 'backed-up' with the epoxy resin based laminate which can be by wet-lay or resin infusion. For resin infusion the slight tack of the gelcoat can be very helpful in the positioning of carbon fibre or other reinforcements into the mould.

Once the laminate is cured the part can be de-moulded and is ready for use; no further treatment is needed and the part will have a highly polishable, glossy, UV stable gelcoat with an incredible, proven bond to the epoxy part.

Compatibility Information - Dos and Don'ts

Although by no means an exhaustive list, the mould materials, pigments and additives listed below have all been tested and are known to work well with GC50.

Compatible Moulds

  • Uni-Mould Mould System
  • Epoxy Tooling Gelcoat
  • Epoxy gelcoat based moulds
  • Polypropylene and polyethylene sheet
  • Aluminium
  • Toughened Glass (eg. flat sheet manufacture)

Compatible Pigments

  • Polyester Colour Pigment * (for vivid opaque colours)
  • Translucent Tinting Pigment * (for less vivid opaque colours)

Compatible Fillers

  • All dry filler powders**

* With bold coloured laminates such as carbon fibre, the underlying colour of the fabric may still show through the pigmented resin, especially with thinner layers of resin over the underlying laminate.

** Although technically compatible, very few occasions would warrant the use of filler powders with a clear gelcoat. Adding filler powders will in most cases negatively effect the clarity of the resin.

Key Processing Information

  • Ease of Use: Suitable for professional and hobby use (follow SDS advice).
  • Odour: GC50 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 2%. Use digital scales.
  • Mixing: Mix thoroughly by hand for at around 2 minutes.
  • Application: Can be applied by Gelcoat spray cup gun or by brush. Maximum thickness 0.8mm.
  • Pot-Life: The pot life at 25°C is 12 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: At 25°C you can expect the gelcoat to be ready to be backed up in around 2-3 hours. The Gelcoat remains bondable for up to 24 hours.
  • Overcoating / Second coatings: Do NOT attempt to 'double gel' as GC50 will NOT bond to itself leading to delamination.
  • Shelf Life: The shelf life is 5 months from date of manufacture.

Downloads (3)

This is a chemical product. Before storage or use you must download and read the accompanying safety and technical datasheets.

Safety Data Sheet (SDS)373 KB
Dutch Safety DataSheet386 KB
Technical Datasheet (TDS)277 KB

Specification

Product Data
ColourClear
Chemistry / MaterialPolyester
Viscosity15000mPa.s
UV ResistanceVery Good
Volatile Content43%
Mechanical Properties
Max Service Temp76°C
Cured Mechanical Properties
Hardness80 (Hard)Shore D
Tensile Strength67MPa
Tensile Modulus3960GPa
Elongation at Break2.2%
Tg Onset (DMA)76°C
Pot Life and Cure Times
Pot Life (Typical)15mins
Initial Cure Time11Hrs
Full Cure Time7Days
Weight and Dimensions
Density1.11g/cm³
General Properties
Gross Weight1.212kg
Can’t find the answer you’re looking for?Ask our technical team a question.

The reason we can’t ship MEKP outside of the UK is because it is highly oxidizing, and standard carrier services do not permit it to be transported.

However you can purchase MEKP from any suppliers of composite materials including fibreglass (GRP) shops, roofing suppliers, boat buildings, car bodyshops etc. There is nothing special about the MEKP we supply, you can ask at your local supplier for ‘Standard reactivity MEKP’; brands such as Andanox KP9, Akperox A30, Butanox M50 (Akzo Nobel) are all suitable and  widely available.

Our GC50 is a durable gelcoat with a good flexural strength so should work well on model aircraft wings and is unlikely to crack in normal usage. Please remember that this can only be used as an in-mould gelcoat (applied first into the mould and then backed up with epoxy and reinforcement). It would not be suitable for ‘hot-coating’ where you apply this gelcoat over an epoxy laminate wing that’s already been made. In this second scenario, the bond would be very poor indeed.

Spraying GC50 is completely feasible without requiring any thinning. The Gelcoat spraying Cup gun's standard 4mm nozzle is perfectly suited for this purpose.

It is designed to work with most epoxy resin systems, although we have not tested it on a large range outside of our own. If you are unsure, we would recommend a small test to be safe.

The standard 4mm nozzle that comes with our cup gun is ideal.  60-100PSI is the pressure range. 

Yes you must use a release agent on the mould surface before applying this gelcoat.

No, we would not recommend GC50 for use with pre-preg laminate/cure. The heat distortion temperature (HDT) of the gelcoat is 76° C which is below the minimum cure temperature for the majority of pre-pregs.

Officially it is by volume, however the densities of the GC50 and MEKP are adequately close to also be able to measure by volume. As this is a catalytic reaction, slight variations in the ratio will not have a significant effect on the cured properties. 

Yes GC50 can be painted. To aid paint adhesion we would recommend keying the surface to around 800 grit and thoroughly cleaning it prior to painting.

Yes, once fully cured, GC50 can be painted. The surface will need to be keyed with sandpaper and thoroughly cleaned prior to painting. Many modern paints will adhere directly to the resin surface, others may need a plastic primer first. Follow the paint manufacturers guidance if you are not sure.

No, GC50 is not suitable for permanent under-water applications. It's fine for use in water - applications like dinghies, jetskis etc. - but nothing that will be permanently in contact with water.

GC50 is based on a polyester resin system and hence any pigments must be polyester based or compatible to work with the gel coat.

You can see our range of polyester compatible pigments here: Polyester Colour Pigments.

No. The reason is that GC50 is only compatible with epoxy when epoxy is sticking to it, not when it's sticking to epoxy. Because it's not designed to work in this way it actually makes quite a poor bond when uncured GC50 is applied to cured epoxy whereas uncured epoxy bonds very well to cured GC50.

GC50 does not require a post-cure, even when cured at ambient temperature it has a heat resistance of 76°C, I would not advise post-curing out of the mould beyond this temperature as this may result in 'print-though'. 

However, if the part is left in the mould the GC50 can be post-cured for brief periods up to 120°C. This does not however make a big improvement in the performance of the GC50 and should only be done if the backing epoxy requires it. 

No, we would not recommend thinning this gelcoat down with acetone. It would damage the resin and the quantities of acetone needed to make it spray would be quite high which could damage any release coating on the mould surface as you spray the resin.

For best results when spraying we would recommend using our Gelcoat Spraying Cup Gun run off a good quality compressor.

Our GC50 is not suitable as a coating on top of art work. It is designed to be used as a gelcoat to be used in mould prior to being backed up by an epoxy based laminate. Definitely not what you're looking for.

A much better product for your application is the ArtResin Clear Epoxy Coating for Artwork which provides outstanding visual results when applied as a coating over various different kinds and types of art, including paintings on wood. All our ArtResin kits include resin and hardener in matched quantities and the resin has no odour and is very safe to use.

Although Spray application is preferred, GC50 can be applied by roller or by brush. This is more suited to wet lay applications as the small brush strokes and slight uneven surface this results in, will not show on the final part as the gaps are filled with resin during the wet lay process.

We do not recommend brush application of GC50 for vacuum bagging or resin infused parts as the uneven surface means the fabric is pressed into the gelcoat tightly and slightly distorted by the uneven surface which can negatively effect the cosmetic appearance of the fabric.

No. The reason is that GC50 is only compatible with epoxy when epoxy is sticking to it, not when it's sticking to epoxy. Because of how it's designed it actually makes quite a poor bond when uncured GC50 is applied to cured epoxy whereas uncured epoxy bonds incredibly well to cured GC50.

No. Polyester resin does not bond well at all to GC50. In fact, only epoxy bonds well to GC50 so if you're looking for a gelcoat that you can back up (or back-fill) with a polyester resin then I would suggest something like our Superior Clear Polyester Gelcoat, which polyester resin will bond to very nicely.

No, GC50 is not fire rated or designed to be fire retardant.

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Shipping Information

Restrictions

In the currently selected pack size, this product is classed as dangerous goods in limited quantity for the purposes of transport.

Shipping is possible to all UK addresses, including the Channel Islands, without restriction. However, due to being classed as 'dangerous goods', delivery times are not guaranteed on any delivery service.

Shipping to EU countries is now done through our European subsidiary based in the Netherlands. All EU customers should use www.easycomposites.eu.

To check availability of shipping to any other country, add the item to your basket and use the shipping calculator on the basket page.

For a full information regarding the shipment of dangerous goods to all destinations, see our delivery information page.

Package Size

There are no package size restrictions or surcharges for this product.

Delivery Cost

To find the availability and cost for delivery of this item to your address, add it to your basket and then use the instant shipping calculator on the basket page.

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