Clear coating wood gunwales

The changing narrative is not helpful. I've heard these words myself recently, btw.

What is see is a poorly prepared surface that is magnified by the topcoat. If you apply a single coat of epoxy; it is not enough to sand back to 400 grit.

320 grit is about the lowest I would go and the finish would need to be immaculate before any two part poly; even paint. If your surface was epoxy paint; it would look exactly the same under two part poly paint; the only difference is color.

Between the popup cleat and the paler wood, I see exactly what I would expect to see if you applied topcoat after lightly sanding the epoxy and the clearcoat does not hide the sanding marks and the clearcoat amplifies the finish or amplifies any flaws.

It probably also locks in heat. So somehow, the clearcoat, in combination with heat and sun, has magnified the epoxy substrate or has trapped heat and made the epoxy degradation process more rapid.

I did google this a bit last night and did some reading that says two part polyurethane clears are crap in the sun for uv protection.

As I said earlier, I have a hard time quantifying the amount of UV protection in the product you used vs Epifanes, but on mil thickness, what I did vs you is significant.

The bottom line is it looks like crap. It seems like the clearcoat amplified all surface imperfections overtime. And I suspect somehow, the light, thin clearcoat and the sun combined for it. My guess is if you touch one side or infrared heat shot the two sides in the same sunlight; one surface is warmer; likely the clearcoat.

But most of the time, a clearcoat or any two part finishes amplify the final appearance of the substrate; they do not hide!

So, some combination of uv chalkout; your incorrect expectation the two pak would hide your flaws; the super thin 2 pak, polyurethane have combined for less than ideal outcome. As for the other surface, there is nothing amplifying the flaws.

If you want to argue about the UV protection of the clearcoat, you need to provide more than heresay. And frankly, that seems to be difficult or impossible without testing.

My final analysis is that the debeers would provide a scratch resistant surface over a perfectly finished paint which you do not have. And, that despite your best efforts, the de beer was a bad choice here.

 

By the way, ask any automotive guy if a clearcoat hides paint flaws.

Varnishes are designed to hide flaws.

I have done enough epoxy work to see orange peel from your rollerwork in this finish, but you never told us you used a roller.