Making salt from seawater
When I told a friend I was going to make salt, her reaction was 'why bother?'. True, it's pretty cheap but I was curious to see the point where it turns from being water to being salt. We had some friends staying and their kids were really interested to see the process, so maybe your kids would like to see it too.
I wanted to get some nice clean sea water, so we went out for a sail in St Austell Bay and collected 5 litres of water from a spot about quarter of a mile offshore.
When we got back, I left it to sit overnight so any big particles settled to the bottom, and then filtered it through a bunch of coffee filters. There were a few specks in the filters, but generally it was pretty clean.
Okay, so this isn't the most environmentally friendly way I could have done it, but waiting for it to evaporate in the UK would have taken weeks. As the water level went down it became more and more cloudy.If you're doing this at home, don't use steel pans! It went a bit rusty.
Eventually it became a white crystalline sludge, at which point we ran it through another coffee filter but this time we kept the solid material.
We spread the sludge onto a piece of baking paper and dried it in the oven at about 85°C for a couple of hours, until it was completely dry.
Once it was dry, the salt had caked into large lumps, so we pushed it through a sieve. Ta da!
In total we got 134g of salt from 5 litres of water. Average sea salinity is 3.5% so the maximum yield was 175g. There was a lot crusted onto the pan, and some of the salt will have evaporated with the water, so this is about right.
In ten days we're leaving the UK for new adventures in Spain...Read more
Archive2016December 2016 (2)November 2016 (2)October 2016 (2)September 2016 (3)August 2016 (4)July 2016 (5)June 2016 (4)May 2016 (4)April 2016 (5)March 2016 (4)February 2016 (4)January 2016 (5)2015December 2015 (4)November 2015 (4)October 2015 (5)September 2015 (4)August 2015 (4)July 2015 (4)June 2015 (4)May 2015 (5)April 2015 (4)March 2015 (4)February 2015 (4)January 2015 (4)
What's this about?
Hi I'm Mat and I'm addicted to new hobbies. I used to think this was a bad thing but now I'm embracing it.
Writing them all up in this blog encourages me to finish projects, and helps me keep track of which ones I've tried.
I always laugh when I hear people struggle to spell words phonetically, when they say random words starting with that letter instead of the standard (if dull) NATO phonetic alphabet...
Also in Making things...
I finally finished my bronze sword project! Kind of...