Sounds sketchy. An arc welding filter will work, I forget the exact grade. 14 I think. But if you let your pupils fully constrict (opposite of dilate) instead of just suddenly looking at the naked sun, it won’t do a lot of damage to look right at it. I’ve heard of people that have permanent spots in their vision from looking at the sun, however. So doing it is stupid especially since there’s no real reason to.
Welder Lens should be #12 or darker. I did use a #10 for a fee seconds. No problem.