One used to be able to get waterglass - sodium silicate - anywhere to preserve eggs for the winter. I've done it myself in the early 80's. I'm looking for a small amount now for ceramics purposes (to deflocculate a clay slip to make terra sigillata for those interested) but can't find the stuff anywhere. Where do poultry keepers get theirs if they still preserve some eggs for winter?
Try eBay; I just spotted it there.
Ah, thanks. I'm not an Ebay sort of person so didn't think of that. I'm the generation that still thinks of shops first. I probably have more options if I go online and get it posted.