Hi.  I use the flexible resin on Ballistic nylon to create a waterproof flexible seal for skin on frame sea kayaks.  I use this product since my previous supplier discontinued their product.  I am happy with EF80 in general but I have found that exposure to water in some instances tends to result in a milky discolouration that disappears once the hull dries off.

Milky discolouration on exposure to water is a sign of moisture absorption.  EF80 is not naturally porous to water once fully cured, so it would indicate the resin part you have made is for some reason not fully cured.  Commonly this occurs quite recently after part manufacture when the resin seems cured and is safe to demould at room temperature, yet can still be sensitive to moisture absorption if exposed to water soon after demoulding. This would normally improve over several weeks as the resin finally fully cures over time. Other factors that could cause this include, poor mixing, inaccurate mixing ratio, low temperature curing or possibly the presence of some contaminants.

Initially I would get the milky parts into a very warm place for a period of time to see if they are still able to dry out. If you are lucky that may solve the problem.  We would suggest that a post cure of parts to be immediately used in water soon after build will help ensure the resin is as cured as it can be and lesson the chances of the resin going milky.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant