Norox MEK-P Catalyst Guide

catalystWe have talked about catalyst long and hard on this blog, a post you can read HERE. But now we are going to look a little more closely at the different Norox products offered in gallon size and up. There are some differences, which most people aren’t aware of, so, let’s highlight those differences here so you can be sure you are getting the perfect product for the job.

These products are offered in both red and clear. The red catalyst is preferred for resin applications so you can easily see if the resin and catalyst is properly mixed. The red color isn’t used for gelcoat as it will affect the color.

Norox MEK-P 9 – The standard catalyst for Noroc, the MEK-P 9 gives consistent room temperature performance with both resins and gelcoats. A reliable product of high purity assures quality in every system.

Norox MEK-P 925 – High dimer content gives excellent performance in most Vinylester resins. 925 also performs well when used with General Purpose and Isophtallic resins. This product is what is used for the 1 oz, 2 oz, 8 oz, pint and quart bottles. This is what is used when a customer wants “high-point 90.”

Norox MEK-P 9H – This product features a reduced level of hydrogen peroxide. 9H is particularly useful in critical gelcoat applications. Another application is in heated, continuous mixing systems for polymer concrete.

Noxox MEK-P 30 – A reduced strength version of the 9, the 30 provides the fabricator more accurate metering control in hot weather or with a highly reactive resin. This is a favorite during the hot summer months.

Tech Tip: Let’s talk Catalyst

Catalyst is an essential element to most processes in our business. Without the catalyst, no chemical reaction takes place and you might as well just pour water over your fiberglass or table. You would think catalyst would be an easy product to work with, and sometimes you are right, but you have to follow the directions exactly. It’s not pretty when you don’t (trust me).

catalystMEK-P or Methyl Ethyl Keytone Peroxide, not to be confused with Methyl Ethyl Ketone, a solvent, MEK-P is one of the most common catalysts. MEK-P is used for polyster and vinylester style resins. It is very specific on ratios and requires the most attention.

Vinylesters require a hotter catalyst we sell, called Norox 925, sometimes referred to as “High-Point 90.” It’s a hotter catalyst that works better for the Vinylester. You will also see Vinylester requires a ratio of 2% by volume, as opposed to gelcoats and resin which are closer to 1.5%.

catalyst chart small

Gelcoat and Polyester resin, including Boatyard use a standard catalyst, or the 925 catalyst. These resins only require about 1.5% catalyst and are quite specific on the ratios, especially in hot weather. You will also use the same ratio’s for Polyester-based putty, like our OEM Super Poly Fill, or our gelcoat putty.

B.P.O. or Benzoyl Peroxide is a cream hardener that is used for most Auto Body and Bondo-like putties. It’s a bit easier and more forgiving on the mixture and comes in Red, White and Blue. The ratio is 1-1 oz tube per quart, or a 4 oz tube per gallon.

epoxyEpoxy activators are all proprietary, depending on the product. They range from a 1:1 ratio, like with our Table Top Epoxy, to our standard laminating epoxy allowing a 1:1, 2:1, 3:1, 4:1 and 5:1, allowing for different ratios that effect hardness and gel time. With different ratios, the higher the ratio, the quicker the pot time and the harder the epoxy.


With all these activators, sticking to the ratio is key, so if you were planning on eye-balling it, may I suggest picking up a couple of mixing buckets, or a squeeze bottle and take the guessing out of the equation.

Are you getting everything you need for your purchase?

One of the top problems we talk to customers about is making sure they get everything they need the first time for their project. It doesn’t sound as crucial for people who live mere minutes from one of our two locations, but it can be, and for people who are hours away, or even across the country, it becomes a necessity. With that in mind, let’s go over some items that are as neglected as batteries on Christmas morning.

Catalyst – Generally, MEK-P is the most neglected product. MEK-P catalyst is 124809essential for all resin and gelcoat; it’s what makes the product hard and it is a requirement that, unless you are ordering a kit, is not included. Make sure you go by the catalyst chart to find out how much you need. MEK-P comes in 1 oz, 2 oz, 8 oz, pint, quart and gallon jugs.

Brushable gel


Brushes or rollers – I can’t tell you how often people get home and get ready to mix their gelcoat or resin or epoxy and stop and wonder how they are going to apply it. For rollers, you want to make sure they are Phenolic roller covers or they will break up while rolling on the gelcoat and resin. With brushes, you can use our Chip brushes, or even our higher-end Glasskoter brushes.

Mixing buckets – Most problems from gelcoat or even epoxy come from either in-proper measuring or in-proper mixing. Many people (including me) go with the tried and true ‘eyeball method’ of measuring. The problem is epoxy and gelcoat are both very specific and very unforgiving on their measurements. If you aren’t exact, you can have a problem. Also remember; a $2 mixing bucket is way cheaper than throwing the product away and re-buying it because it didn’t harden properly. We sell mix and measure buckets perfect for mixing (and measuring) with measurement lines on the side in pint, quart, 2-1/2 quart and 5-quart sizes. For catalyst, we sell measuring cups, and my favorite, a squeeze bottle for quick, easy measuring.

Safety equipment – We’ve already talked a bit about safety equipment here, but it’s surprising how few people use gloves. Gloves are a vital part to a persons protection and it’s a cheap, easy purchase. A box of gloves is as inexpensive as $6.07 for a box of 100, so pick them up and they will last you a few projects.

solventSolvents for cleanup – Cleanup is one that almost always overlooked until the project is finished and the mess has been made. Gelcoat is not like paint, where you can use a damp rag; for gelcoat and resin, you will want to use Acetone for your cleanup needs. For epoxies, you will want to use T-12 and for paints, you will want to use mineral spirits to get the residue up. Just remember, with all solvents to be careful how and where you use them as they are harsh and can damage certain surfaces (like wood floors…don’t ask).

So, next time you need a project and you are at the showroom, or on our website, remember to get everything you need so your project can turn out amazing.