> Does anyone know of a good waterproof glue for wood that does not need to
> be mixed?

I don't think I'd trust anything short of epoxy for real waterproofness. West Systems makes a "5 minute epoxy" which does need to be mixed but uses a forgiving 1 to 1 mixture ratio...very easy to eyeball small batches for spot fixes. I've used it for small "fixes" here and there and been happy with it. (I'm not sure of the price, but it's fairly cheap.)