I bought this powder to make my own sunscreen because store bought natural zinc oxide sunscreen is stupidly expensive. Though I came across other, cheaper 1 lb. bags of zinc oxide in my search, the fact that Better Shea Butter says clearly in the description that their powder is made in the US, non nano, and uncoated, I figured it was worth the extra money for the peace of mind. With most sunscreen recipes calling for only a few tablespoons of zinc oxide for an eight ounce yield, this bag will make about a gallon of sunscreen, if my math is right. Is it right?
1 TBSP = .5 oz, 16 oz in a pound, 2 TBSP per 8 oz of sunscreen, 16 cups in a gallon-yes.
AT ANY RATE, it will make a lot.
This is the recipe I followed/modified (though, I'm sure a lot of people have already come across it): http://wellnessmama.com/2558/homemade-sunscreen/
I used:
¼ cup grapeseed oil
¼ cup olive oil
¼ cup shea butter
1/8-1/4 cup beeswax (I used leftover bits of old tealights)
3 TBSP zinc oxide (I wanted a higher SPF...though how much higher it is, I have no idea)
I followed the instructions about heating and everything came together nicely! It's a pretty thick consistency but it spreads easily, sort of like Vaseline. I will note that I was impatient and made the base before my powder arrived, and mixing it in after the fact yielded a slight lumpiness, but it's not too bad and is my fault completely. I suppose I could have reheated it but eh!
Obviously, there's no reason not to just add this powder to a lotion you already have, but I already had all of this stuff on hand and wanted the slight waterproofing effect of the wax.
FULL DISCLOSURE: I have not actually tried this sunscreen yet, but there's no way it's any different from other sunscreens, except that it's cheaper and has the ability to make other, lesser people fear your DIY prowess, probably.
UPDATE:
I went to the beach for two days, slathering my skin with this sunscreen the entire time; it was fairly heavy and sort of streaky, but seeing as I wasn't heading to a SI bikini photo shoot, I didn't really mind.
I was out for about three hours the first day and I reapplied once; I got burned. The second day, I was out for four hours and reapplied at least three times, but ended up getting burned worse.
It's possible that perhaps the sun was just insanely strong or that the beach was the wrong place to expose my skin for the first time in about a year, or that I didn't dump enough powder into my mixture, but I would just be wary. I've used Badger sunscreen at the beach before without much incident, but that was in September, so who knows! Maybe natural sunscreen just plain isn't as effective as chemical. Don't stray too far from the shade if you go this route!