This month, we’re sailing past the half-way buoy in our race to discover and debunk the 10 myths of epoxy. They say epoxy won’t cure in the cold or cure underwater but not so says our epoxy guru David Johnson.
Myth 5: Epoxy won’t cure in cold weather
I can understand where this myth comes from, although it’s still a myth at the end of the day. Our WEST SYSTEM® 105 epoxy with 205 fast hardener® will actually cure at temperatures of just 5°C but it’s far from the optimal temperature for working with epoxy.
Just think of epoxy being a bit like honey. If you put it in the fridge it gets viscous and difficult to spread on your toast. In the case of epoxy you might not be able to wet out glass cloth quite so easily, or it might be harder to achieve the desired consistency when mixing epoxy with fillers. There’s also the risk that coatings go on too thickly, creating a subtle exotherm which can lower viscosity rapidly and increase the risk of running.
So what can you do to work successfully with epoxy in colder weather? The first thing you can try is warming up the epoxy (think of the honey example again). You can also create a tented area and use a small blow heater to increase the temperature where you’re working. That way the epoxy will be much easier to work with and you’ll get the best possible results and finish.
And the perfect temperature for working with epoxy? That has to be t-shirt temperature, meaning that if you’re comfortable working in a t-shirt you’ve got it right. For those who need a figure, let’s say 15°C!
Myth 6: Epoxy won’t stick underwater
This is definitely a myth. Some years ago we heard from a customer who tried to get rid of some left-over epoxy by flushing it down the toilet. It cured and stuck to the toilet pan and he eventually cracked the toilet trying to break up the epoxy with a chisel.
When it comes to emergency hull repairs and the like, we definitely wouldn’t recommend using epoxy below the waterline. However, WEST SYSTEM products might just buy you some time in the case of an emergency. We’ve actually had some success by applying some of our G/flex 655 product to a fibreglass plate and carrying out temporary emergency repairs under the water.
For this reason, we think more of our customers should pack G/flex® 655 epoxy and fibreglass sheets as part of their essential equipment on board. It’s one of those things that you hope you never need but it could be as vital as a pair of flares one day in an emergency situation.
Thanks very much to David Johnson for another expert contribution. Look out for part 4 next month!
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