I'm currently in the midst of installing new Marvin Ultimate Replacement Casement windows into the gutted frames of my old double-hungs. The wood on the Marvins is a very light Ponderosa pine. All the new jamb extensions and casing will be semi-clear pine (few knots and some grain variation). The two match fairly well, despite the occasional knot on the extensions...but those can be filled with a light-colored putty.
My question is about finishing these wood surfaces. Since these are casements, there is the potential for the interior part of the window (wood) to get wet, should the window happen to be open during a rain. For the most part, our 24" eaves will protect the wood, but nothing will stop sideways rain!
I'd like to cover everything in a VERY CLEAR poly. Something that won't change the color of the wood, and won't yellow over time. ACE makes a water-based poly that I've used several times, but I don't know how it would work in this situation. Might be fine.
Is there something out there that is specifically designed for this purpose? I'd also like a satin or low-gloss sheen. I don't want the "wet" look. I want the wood to look as close to un-finished as possible, while still being protected.