What is the best clear coat UV resistant for a large oak frame window?

hello,

Your problem is not too ahrd to resolve. If the frame is inside, you need to get a poly-urethane with a UV-Blocker. Most off-the shelf indoor poly-urethanes do not. This means that the wood will deepen in colour over time Now, if it's outside, the Exterior rated poly-urethanes usually contain a UV blocker. This means that the wood colour, especially the stain, will not fade over time. If it is inside, I believe that Lee Valley tools carries a poly-urethane with a UV blocker. go to www.leevalley.com for more info. You can use the exterior version inside, but make sure your area is VERY well ventilated because of the extra fumes. Definatly use an oil base poly as compared to a water based becaus ethe water base has poor scratch resistance and resistance to alcohol and cleaning products is minimal in comparison to the oil based. I would recommend a semi-gloss, 3 coats with a light sanding in between coats with a 220 grit sand paper. this is done to simply smooth the surface and allow the next coat to bond better. For a harder finish simply apply more coats. You most likly do not want to use a high gloss because it is too shiny., A satin may be in order, but it all depends on finishes on the rest of your house. Varathane is a great brand for the poly-urethane and is widely available at almost every hardware store. Go for the diamond finish. It may cost a bit more, but the finish is much stronger and looks better.

minwax, satin finish clear coat varnish is great to use, fast drying is good but not as good as the slower drying stuff, it get's into the oak better...good luck