welding the heavens

June 5, 2012 2:16 PM

Transit of Venus - the welding mask edition.

So, in about an hour, the transit of Venus will begin here on the west coast. I have a welding mask that auto-darkens to #13. Advice has been to use a welder's mask rated at #14. I have had no luck in locating a mask or goggles rated at #14. Can anyone give viewing advice on #13 vs. #14? I'm not planning on using something unsafe to view this event, but advice would be appreciated on best practice with a a #13 lens.

posted by Bohemia Mountain to science & nature (3 answers total)

Don't do it. I have always seen that #14 should be used, and that #13 is not good enough. Eye damage from looking at the sun can show up years later sometimes, so this is not the sort of thing you want to "try it and see." This reference backs me up, and also provides some alternatives.
posted by ubiquity at 2:32 PM on June 5, 2012 [1 favorite]

http://www.skyandtelescope.com/observing/objects/eclipses/3306081.html?page=2&c=y

Here is a source that specifically references #13 and #14 as safe.

Standard disclaimers apply that I am not an expert, know the risks involved before you try this at home. I once tried to purchase a #14 and they were out of stock, the salesperson had extensive knowledge of welding glass said that the difference between #13 and #14 are negligible.

Again, proceed with caution and know the risks!
posted by kuppajava at 3:14 PM on June 5, 2012

The link from kuppajava is for a lunar eclipse. Venus covers a much smaller area of the sun, and I don't know how much that affects the relative brightness compared to a lunar eclipse. I would still be cautious.
posted by yeolcoatl at 3:43 PM on June 5, 2012