On our “to do” list today is to make homemade Gak. In texture it comes out as halfway between Silly Putty and commercial Gak, with an interesting moistness that to my adult sensibilities is exactly that of a clammy palm.
So I was wondering, what’s the chemistry behind this? It involves adding borax to Elmer’s glue. I know that Elmer’s glue is casein-based, so does the borax just coagulate the milk protein into Gak, or is there an actual chemical reaction? It leaves extra water behind, which you have to pour off.
And what unsung genius first discovered you could add borax to Elmer’s glue and make playdough? I’m familiar with the story of the invention of Silly Putty, but I’ve never heard how they came up with Gak.
I am having an awful time getting this link to make. Here’s the complete URL–I notice it has another URL embedded in it, maybe that’s why it won’t make. If you click on it, a “Page Cannot Be Displayed” comes up, which is stupid, because I have it bookmarked and I don’t have any trouble getting to it myself. Is it some kind of a double link and vB no speaka da English? It’s from the about.com Family Crafts page.
If you want to follow his link, remove the space between “www.kid” and “sdomain”. Had this bite me once, too. Apparently, vBulletin winds up inserting a space when it tries to handle long URLs. The form with the link quoted in the url vb tag should work. Let’s try it:
Well, huh. I distinctly remember being told back in the 1960’s that Elmer’s Glue was made from milk, hence Elsie the Cow on the bottle. But I went and found the Borden’s MSDS sheets and sure enough, it’s polyvinyl acetate. http://www.elmers.com/msds/