Question: When cleaning my wood stove glass door (Quadrafire) I noticed an area in the center that will stay a little bit milky no matter how often I scrub it. I am using the stove cleaner from a spray bottle which is sold at our stove shop specifically for glass cleaning. Our stove was used almost daily for four months, usually from early afternoon until bedtime. Mostly oak, juniper plus a little manzanita and pine. No dirty wood. The glass was cleaned about every other day and only when cold. Typically it never got very dirty but I wanted to wipe off the fine ash layer. I have read in the Q&A that minerals in the firewood cause this, or maybe the caustic ash does. But is it normal to see a clouding of the glass after only one season of use? Answer: Yes, it is normal. This can happen in a matter of days if the conditions are right. The glass can get etched if when very hot the ash is allowed to contact it. The glass can actually get "sticky" when very hot and fly ash can get permanently attached. The only way to get rid of the "gray" is to replace the glass pane. It is really hard to prevent when you use your stove as an all-day every-day heater. Most of us who use our stove that way just learn to put up with it. If you are really careful to push your ashes away from the door every time you load, and you wipe of your glass every day, you may be able to keep it from etching. But the work involved to do this is often more than it's worth.