I live in an old building with a set of 3 solid wood exterior doors, which my landlord has left to rot and has not varnished in years. The varnish has completely disintegrated in the lower parts which are more badly hit by sun and water. You can literally rub it away by hand.
I've decided to varnish at least the bottom parts, so as to protect them from another harsh winter--otherwise, I don't think they will survive. Not interested in perfect looks, just to protect the wood and a reasonable match.
Problem is, where the wood has been damaged, anything you apply greatly darkens the wood--so it becomes really different from the upper parts which have some of the old finish there and take the varnish without darkening.
Sanded down to the bare wood, it looks like a gray wood. Once you apply any finish, it turns a very dark cherry.
To add to the complication the old finish which has survived nicely in the upper parts seems to be some amber colored varnish. It is NOT a stain, but a rich, golden amber finish that sits on the surface of the wood. It almost looks like shellac, but it could not possibly be, I suppose, as it would not last outside.
I have tried using a wood conditioner, a gel stain, water based exterior urethane and spar urethane (separately of course, on different spots)--all produce a darkening in the bottom, bare parts.
It seems to me now that the old finish simply had a pigment that produces a color sitting on top of the wood, and covering the bare wood color. But what could that be? I have not found anything on the market that would work for outside.
Yes, of course the color has changed with the sun and weather, I'm not expecting a perfect match, but I still want to know what varnish looks like it has some dye in it. This is not simply multiple layers of varnish.
Any ideas would be immensely helpful!