I've seen them before, but IIRC, someone sent me one of theirs with their helmet for the commission, and for some reason, the visor was not large enough and was not nearly wide enough to span the length of the upper visor "squint"
While I did buy two welders visors from Amazon, they come flat, and all attempts to heat it (short of a heat gun, cause I know that will cause bubbling of the surface) failed, as I guess it is intended to take a considerable amount of applied heat to affect it's shape. I did find another supplier for the face shields, and they appear to be already formed in a curve, which I think is what I need to really make this work without putting a lot of stress on the post's connection.
I think I may go ahead with using JB weld. I'm not too concerned if I use that. I can at least move forward with painting the helmet in the mean time. Worse case, I use expoxie or hot glue to hold the visor in, but I really want to make this work....
