Bob Dahse

McMaster, Cambridge Wire Cloth, and Darby Wire Cloth are all fine screen sources if you want a 100-foot roll. We offer type 304, 12-mesh, plain-weave stainless screen in 2-by-2 foot squares from both our website (http://www.geopathfinder.com/Solar-Food-Drying.html , for the cheapest price) and from several E-Bay listings. I've been told that our price is about 1/3 of what could otherwise be found for small quantities. We sell the 2 foot square size to match the 4-foot by 100-foot rolls of screen we buy, and to match the 2-by-2 foot screens used in our radiant solar dryer design. Since 1982 we've been experimenting with various designs, screens, collectors, and mesh sizes to find what works the best in our humid, 45 degree latitude, half-time-cloudy location, but which can be modified to work for many different crops at higher/lower latitudes, altitudes, and temperature.

Hello again, I'm back on the forum after having been locked out of my account for a couple of years. I see on our website stats that lots of folks are linking back to the old posting we did about the radiant-style solar dryer for humid and low-sun climates we designed back in 1985. Thanks to Jason for posting the new link to the GeoPathfinder-dot-com site, and for his comments about what makes the design so effective! It works far better than the box-style air heating driers in humid areas or those at higher latitudes. And it has been built and used worldwide after HomePower magazine and the United Nation's alternative energy publication covered it back in the late 80s. In areas with less humidity, more heat, more solar strength, or for those who strictly dry herbs, the dryer can be "throttled back" in efficiency by simply draping some shade cloth over it. But it's nice to have the full efficiency on a partly cloudy, cool day, when you need to dry something really wet. It's commendable to utilize recycled stuff to build it, and the physical principles that make it work can even be used without having to actually build a dryer (if you have a parked car sitting around with a large window faced south - in the Northern Hemisphere, that is), but the size of the collector is rather important. We've found that here in the upper Midwest a 4-by-4 foot dryer is pretty much the minimum to get veggies reliably dry. Anything smaller north-south doesn't build up quite enough heat at the top of the dryer's slope (works for herbs/greens though), and anything narrower can get east-west crosswinds that suck away the heat too quickly. And be careful with out-gassing plastics affecting your food. The metal collector sheet may keep the gases away from your harvest but I still lean toward hard plastics or glass. Feel free to e-mail us from our site if you can't find answers to other questions about it.