Epoxy test panel after six month

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The Epoxy Panel after 6 months


	This is what the panel looked like when it was new. The panel below reflects changes after two months outside. The third panel shows the epoxy after six month of continuous exposure to the elements.
	Panel at 6 months (compare the light band in the middle)

	I have omitted the close-ups of the individual epoxies because the changes are too subtle to be picked up by the camera at this distance and displayed visibly at 72 dpi (dots per inch) monitor resolution. The plastic 'light shield' covered the middle band between the red dots at the edges of the photo.
	Observations
	Fabric 'whitening' - It was clear from the two month test that fibers coated with a thin layer of epoxy showed signs of discoloration. The thin epoxy coat has now succumbed to oxidation particularly on the blushing epoxies such as the WS206 and the EastSys. Patches of the WS206 are severely eroded from water penetrating into the fibers which caused complete delamination of the 'filler' layer of epoxy. It is interesting to note that the WS206 is supposedly more water resistant than the WS207 but it just doesn't stand up well to UV radiation. The whitening of the fibers on the other samples has stabilized and is not much worse than it was four months ago. Erosion of WS206 below: click on image for magnification
	Color changes and surface oxidation- The most striking fact is that the divergence of the epoxy characteristics occurs mostly in the first few months of the test. The rate of change (mostly coloration of the wood) slows down noticeably after two to three months. The darkening of the exposed panel is clearly seen not so much by the photo itself but by the relative difference between the 'light deprived' band and the rest of the surface. It also appears that the varnished and unvarnished areas on all epoxies darken at the same rate. One would assume that the varnish would shield the wood form the entire spectrum of UV light but this doesn't seem to be the case. It, on the other hand, is working very well at maintaining gloss and keeping the epoxy from oxidizing. Speaking of oxidation, the surface of WS207, Raka and System Three maintain the same glossiness (covered and uncovered). The exposed surface of MAS epoxy shows the most degradation in gloss relative to the 'light deprived' band as well as other non-blushing epoxies. The surface starts showing signs of UV damage in the form of microscopic 'spider veins' one would see on old oil paintings. A few short months ago, this used to be a very glossy surface (MAS epoxy): click on image for magnification The blushing epoxies (WS206 and East System) are completely dulled by oxidation on the exposed parts of the panel but still maintain gloss under the 'light exclusion band'. If I were to coat my boat now without having any varnish for UV protection my preference would be as follows: Raka or WS207 System Three MAS East System WS206
.	Epoxy shrinkage - All epoxies show substantial shrinkage and fabric print-through. Here is an example of Raka print-through. click on image for magnification
	Varnish 'water resistance' - The varnish is holding up really well and I can't discern much change except a slight "loss of gloss". See 12 months results .
	Back to Epoxy Results , 2 months or 12 months results page

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Last page update: 11 January 2020