Where to Buy MEKP Catalyst

Due to airline regulations, MEKP catalyst is one of the only products we are unable to send to ship to customers in the USA. Fortunately, MEKP catalyst is universal and widely available. This page is provides information on what type of MEKP to buy locally and where to buy it.

MEKP (methyl ethyl ketone peroxide) is the universal catalyst (hardener) used to cure polyester and vinylester resins; without it, these resins cannot be cured to their hardened state.

MEKP is required for the following Easy Composites resins:

• GPX Premium Polyester Laminating Resin
• GCX Clear Polyester Spray Gel
• IP2 Polyester Infusion Resin (ISO)
• GC50 Epoxy Compatible Clear Polyester Gelcoat
• PCP Polyester Pattern-Coat Primer
• PCG Polyester Pattern-Coat Hi-Gloss
• UG1 Uni-Mould Tooling Gelcoat
• UC1 Uni-Mould Coupling Coat
• UT1 Uni-Mould Tooling Resin

Due to airline dangerous goods regulations, we are unfortunately unable to ship MEKP catalyst to customers in the USA, which is why it is unavailable to buy on this website.

However, MEKP is universal, inexpensive, and widely available and so, if you want to benefit from using any of Easy Composites' range of special high quality polyester and vinylester resin systems, we suggest purchasing a quart / 1 litre pack of MEKP catalyst from a local supplier that can then be used with our full range of polyester and vinylester based products.

What type of MEKP do I need?

Most MEKP catalyst sold will be suitable for use with Easy Composites' polyester and vinylester resin systems but you will sometimes find MEKP available in various ‘reactivities’. If you do, we strongly recommend purchasing ‘standard’ or ‘medium’ reactivity MEKP. This is the type we expect our resins to be used with and so when we suggest a catalyst ratio of, for example, 2%, we mean 2% of standard reactivity MEKP.

If the supplier of the MEKP you are buying does not mention the reactivity then it is probably standard reactivity, although it would be worth checking with them first. If you see high reactivity or ‘cold weather’ MEKP or low reactivity or ’hot weather' these should be avoided as they will be more or less reactive than our products are designed for.

Some examples of standard reactivity MEKP typically available from US suppliers include:

• Luperox DDM-9 (Arkema)
• Norox MEKP-9 / Norox KP-9 (United Initiators)
• Butanox M50 (AkzoNobel)
• MEKP 925 (Organic Peroxides)

How much MEKP do I need?

MEKP catalyst is added in very small quantities to polyester and vinylester resins and so a little goes a lot way. Typical percentages are 1-2% by volume, meaning that for a gallon of resin you would need just 3.2fl oz of MEKP. However, MEKP is inexpensive and is used universally across all our polyester and vinylester resins and so it makes sense to purchase enough MEKP for all your current and upcoming needs, whilst keeping in mind that MEKP has a very short shelf-life of just 2-3 months (see below).

If you want to purchase the appropriate quantity for a single pack or resin or start kit, use the quantities below:

Where can I buy MEKP locally in the US?

MEKP can be purchased from any composite materials supplier, in store and online. MEKP is also commonly available from boat yards, chandlers and many auto repair shops. Anywhere that sells materials for conventional fiberglass should stock MEKP.