10 myths about epoxy cured : Part 5


Epoxy is mysterious stuff, hence why there’s so many myths about it. Some say, for example, that its pot life is too short, and that it’s harder to use than Polyester resin. Nonsense, says our resident professor of epoxy David Johnson.

Myth 9: Epoxy’s pot life is too short

It’s true that epoxy waits for no man, but planning effectively and working the right way can give you a longer working time.

One important thing to mention here is that we calculate a working time of 20 minutes based on mixing epoxy resin and hardener in a small paper cup. This is standard practice which allows you to compare working times between manufacturers, but you can buy more time by mixing your epoxy in official WEST SYSTEM® mixing pots, which are short and stout.

By reducing the depth of epoxy in the mixing pot, you also reduce the intensity of the exothermic reaction – which is why you get more working time. If you could mix your epoxy in a roller tray, you’d get even more time, but achieving a good mix would, of course, be impossible.

Another way you can extend your working time is by using WEST SYSTEM pumps. One pump of resin and one pump of hardener give you approximately 24 grams of mix, which is perfect for small jobs. With experience, you can work your way up to three pumps of each and still have time to work. As well as being the fastest way to measure out and mix epoxy, pumps help you work more cleanly, with no need to pour and weigh the epoxy resin and hardener.

Myth 10: Epoxy is harder to use than Polyester

When it comes to choosing a resin system, it’s definitely horses for courses and Polyester and Vinyl-Ester resins definitely have their place in boat building. Many times, professional boat builders have experience of working with both epoxy and Polyester and they find them both as easy to work with.
However, there are some reasons why epoxy might be a more convenient choice for amateur boat builders, DIY enthusiasts or anyone who hasn’t worked much with resin/hardener previously.
First, Polyester often comes in large packs, which might not be convenient or cost effective for all users. Second, WEST SYSTEM pumps make epoxy easier to measure out and mix, with no need to weigh Polyester and catalysts. Thirdly, inexperienced users may find Polyester more pungent than epoxy, which could be off-putting, especially if you’re working in a confined space.
So no, epoxy definitely isn’t harder to use than Polyester and it might even be easier for some people who are inexperienced working with different resin systems.

Thanks to David Johnson as always for his epoxy insights. This is the last episode in our myth-busting blog series – we hope you enjoyed it!

Did you miss part 4 of the series? Find it here.

Learn more about the full portfolio of WEST SYSTEM epoxy products.


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