Many years ago, when I was a stupid kid, I used to hold a candle to a piece of glass and once enough soot deposited on the glass, the homemade filter was ready. Luckily, holding the filter up to the occular and scraping off the soot in the process, I did not allow any direct sunlight to enter my eye
. Otherwise, try going to a store that sells welding supplies. You should be able to purchase lenses for a welding hat that have the right opaqueness for your needs. I did this and although the image is greenish, it worked out fine for observing the sun through a telescope or binoculars (holding the lense over the objective in binoculars to protect the optics from image-generating heat and over the occular in a scope but be careful of heat build up within the occular). This method also works fine for viewing solar eclipses - just hold the lens up to your eyes or store it in your shirt pocket. One warning - these lenses are VERY brittle and break easy with any kind of stress on them. Mr Q