How about beeswax and a blowlamp to impregnate wood and joints? I wouldn't paint mine with gloss anyway but heated wax is good for later maintenance to seal joints.Ashforth Feeder from Thornes, what type of paint is used to waterproof the inside. Its currently white.
If its something strange, where do you get it from?
Yes and no. I had checked it was waterproof for an hour or two, but as a belt and braces approach, I soaked it in case the weight of the syrup deformed the feeder.Not all PVAs are waterproof and will peel off sooner or later if wet. It was the soaking that solved your problem, but only temporarily, as when the water dries out, you will be back where you started.