How to weather protect plywood fence

backyardfencelumberoutdoor

My handyman guy used the wrong lumber to make this fence gate. It just regular plywood used for subfloor:

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It's too late now to take it down. But it looks OK so I want to see if there is a way to weather protect it.

Eventually it will be painted (white color now is Kilz prime). What product should I apply to seal it from rotten?

Best Answer

Painting may be your best friend here, but I hate to be the bearer of bad news. Where the purlins meet the OSB will never be painted unless they are removed, then after they are painted, the holes from the nails holding the purlins in place may be the weak spot.