# What's the chemistry of homemade Gak? **URL:** \ **Category:** Factual Questions\ **Created:** [August 2, 2000, 1:45pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839 "2000-08-02T13:45:08Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [August 2, 2000, 1:45pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/1 "2000-08-02T13:45:08Z")
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](http://about.com) Family Crafts page. [http://familycrafts.about.com/parenting/familycrafts/gi/dynamic/offsite.htm?site=http://www.kidsdomain.com/craft/gooeygak.html](http://familycrafts.about.com/parenting/familycrafts/gi/dynamic/offsite.htm?site=http://www.kidsdomain.com/craft/gooeygak.html) ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [August 2, 2000, 3:29pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/2 "2000-08-02T15:29:45Z")
I thought most white glues were polyvinyl acetate, not casein. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [August 2, 2000, 3:31pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/3 "2000-08-02T15:31:00Z")
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: [HERE](http://familycrafts.about.com/parenting/familycrafts/gi/dynamic/offsite.htm?site=http://www.kidsdomain.com/craft/gooeygak.html) ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [August 2, 2000, 3:32pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/4 "2000-08-02T15:32:54Z")
Nope. That netted me a space in another spot in the URL. ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [August 2, 2000, 9:17pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/5 "2000-08-02T21:17:54Z")
> [@](#): > > \*Originally posted by Padeye \* > \*\*I thought most white glues were polyvinyl acetate, not casein. \*\* 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/](http://www.elmers.com/msds/) So, huh. ---
**Author:** ![funneefarmer](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@funneefarmer](https://boards.straightdope.com/u/funneefarmer)\ **Post date:** [August 2, 2000, 9:25pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/6 "2000-08-02T21:25:54Z")
Try [gooeygak](http://www.kidsdomain.com/craft/gooeygak.html) ---
**Author:** ![funneefarmer](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@funneefarmer](https://boards.straightdope.com/u/funneefarmer)\ **Post date:** [August 2, 2000, 9:30pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/7 "2000-08-02T21:30:35Z")
For an explanation try [cross linked polymers](http://www.sd01.k12.id.us/schools/borah/teachers/purdy/elemid/edufest99/elmers/elmers1.htm) ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [August 2, 2000, 9:35pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/8 "2000-08-02T21:35:31Z")
Perhaps Elsie and Elmer were used merely paid spokescows for [URL="[http://www.lileks.com/institute/gallery/ads/hemo.html](http://www.lileks.com/institute/gallery/ads/hemo.html)"Borden, as in this disturbing ad. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [August 2, 2000, 9:36pm UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/9 "2000-08-02T21:36:35Z")
Damnit! [Borden](http://www.lileks.com/institute/gallery/ads/hemo.html) ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [August 3, 2000, 3:57am UTC](https://boards.straightdope.com/t/whats-the-chemistry-of-homemade-gak/27839/10 "2000-08-03T03:57:48Z")
Thank you, **Funneefarmer,** that was exactly what I was looking for. \*\*Padeye–\*\*well, thank you. I think. :rolleyes: “Never underestimate an ungulant who can knit with her hooves.” My thought for the day…