You can purchase Greensand from Artisan Foundry
Artisan Foundry Store can also supply all the other products you may require by mail order at very reasonable cost.
Bromsgrove Greensand from Artisan Foundry
This company gives excellent service, I placed an online order for sand on a Monday evening and it was delivered by noon on Wednesday.
Although described as ready to use this means there is no need to add anything to the sand like bentonite clay before use. It does in fact need a little preparation.
As supplied my sand was too wet, it could have been too dry as the moisture content is determined by the weather conditions when dug, sieved and packed.
The first thing I did was to tip the sand onto a tarp laid out on the drive and spread out the sand with a rake. An hour in the sun and it was ready for the next step. In industry the sand would be put through a muller to condition it. I have a large kitchen sieve.
The sand was passed through the sieve and a nice fine mouldable sand emerged from the bottom. There were a few small stones that needed discarding but this must be expected from a product that has been dug from the ground. Be aware though that some of the "stones" are in fact little balls of sand and can be broken up for use. The sand was now too dry to use so after spreading out on the tarp again water was sprayed on and the sand turned over a few times and it was ready to use.
It may take a little getting used to how much water is needed. It should hold it's shape when squeezed in your hand and you should be able to see the creases of your hand imprinted in the sand. It must not stick to your hand though, if it does it is too wet. It is dangerous to pour hot metal into a mould that is too wet as the moisture will turn to steam and can project moulten metal from the mould.
Always wear protective clothing , face shield and gloves are essential.
I would recommend getting some proper greensand if you can but it is not available in your country you could make your own.
Make your own Greensand
I thought it would be helpful to others if I had a go at making my own greensand.
I was given a bag of bentonite clay in pellet form from a friend who drills boreholes. It would be easier to use the bentonite in a powder form but this was free, so I thought I would give it a go.
I looked around for some fine sand. Builders suppliers sell a fine sand to go between the joints in block paving so I bought a bag of that to try. I felt it was a bit too coarse so I then bought a bag of children's playsand which was just a touch finer.
First I dried the sand and the clay so I could accurately repeat my mix. I thought I would start with 7.5% clay and work up until the correct bond was achived. 10% is the usual reccomendation but I found 12% to be better.
1000g of the sand was weighed out and 120g of the pellets. The pellets were broken up by putting them in a plastic bag and attacking them with a hammer. They were then put in a container with a little water and the mix stirred until all the lumps were gone.
Sand was added and they were mixed together. It is necessary to completely coat every grain of sand with the bentonite so it's not just a matter of stirring then together. I had a steel rod with a ball on the end and I was able to push the sand down hard whilst stirring. The specification of the clay states the clay will expand by 500% in 48 hours so after an initial mix it was left to rest for a day then mixed again. I needed a rest too!, it's not easy to mix. I gave it a mix each day for the next few days.
Mixing was continued until no traces of the grey clay could be seen against the golden sand and then it was left a further 24 hours before I tried a mould.
The mix came out too wet but I helped it dry with the aid of a hot air gun. Its February as I write this, if it were summer it could have been left out in the sun to dry, but beware of the neighbour's cat who thinks its a litter tray!
After use the sand can be prepared again and reused indefinitely.
Below is the video on how my sand was made.
