If u still want to use the 3" as a solar scope, go find a #14 welders lense (any welders shop, Lowe's or maybe big hardware store). Make a full aperture stop for front of scope outta cardboard , cut a 1 5" circle in it, place lense over hole and securely tape asaembly to front of scope absolutely assuring any light entering scope only comes thru lense. Done this a few years ago with an 8", worked great for sunspots.