5 Key Points on Laminating Epoxy Resin

We can guess that you have used Epoxy before, if not, more than likely you have seen furniture, an object or project with epoxy on it. Now, Epoxy is not the same as Polyester and Vinylester due to its chemical properties. Another difference is, Polyester and Vinylester uses the same hardener and as a result, the appearance between the two are similar, while epoxy tends to have a slight yellow or amber appearance. 125463There are many different categories of epoxy, so today we will highlight one of them; laminating epoxy.

1) The laminating system cures to a high strength moisture resistant plastic, with good physical properties.

2) The ratio is well suited for use with high-solids marine, maintenance coating and bonding agents.

3) The cure time is three days in the sun or a week if it is not. Set time changes with activator and film thickness.

4) If there is an excessive amount of activator applied , the laminating epoxy will be soft and rubbery. In contrast, if there is not enough activator, the epoxy will not cure hard.

5) The epoxy cures faster in high temperatures in thick layer applications.

Please note: additional recoating of this material is thoroughly cured. If the product has cured hard and tack-free, a light sanding and solvent wash is advisable before recoating.

 

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.

Tech Tip: Storing Resin

resinStoring your resin is an important part of any job. The leftover resin isn’t something you can just discard, nor would you want to. We’ve got some tips on how to store your resin to make sure you have the most bang for your buck.

  • Keep resin in its original packaging. Those containers are approved for resin and do not get thinner overtime.
  • Do not keep mixed resin. If you add anything to it, you need to use it or lose it.
  • Keep out of the sun. Make sure your resin is stored in a cool, dark place. Our techs even suggest storing them in refrigerators (just not with food).
  • Write on the container when you purchased the resin.
  • Know the shelf lives of your products. A good rule of thumb is 3 months on Gelcoats and Polyesters, and 12 months on epoxies, provided your store them properly.
  • If the product is over its shelf life, it doesn’t necessarily mean its garbage. If it still looks ok, do a test piece to see how it sets up and go from there.
  • Do not store the product on concrete.

Now that you know how to store the product, get out there and make your project look amazing!