I lucked out. My estimate of correct resin to catalyst ratio must have been close, because the questionable batch of resin cured.
Unfortunately, I missed a few places, and will have to play catch up with the next couple of coats. Unaccountably, I found holidays on the under-side.
And I’m stalled for today – it’s been raining since 10 AM, and I don’t have an inside place to work. Ah well, at least the resin cured.
My goal is to fill the grain with epoxy and completely seal the wood. Then UV protect it with 7-8 coats of varnish. That should keep any rot and black spot away, as long as I repair the scratches immediately.