According to the NASA total eclipse website, a shade 14 welding lens is the only lens adequate for viewing the eclipse. http://eclipse2017.nasa.gov/safety
Having net problems - very slow -so haven't verified that info. NASA site taking forever (for me to load) ...
Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good ...