Mark Frauenfelder (mark) Mon 27 Jan 03 14:31
Hi Rockyshoe! I'm so glad you and your kid had fun with the book. My daughter never gets tired of making slime (and neither do I). I found a great new substance to mix with the borax solution - liquid starch. You get a "dry" slime from it. Mark, I do most of my drawing on the computer. It's just so dman convenient. I love being able to swap colors around. Sometimes I'll start with a pencil sketch and then scan it and trace over it in Illustrator using my Wacom Graphire tablet. I don't often go into photoshop. I use Image Ready to convert Illustrator files into jpgs and gifs for web work.
Gail Ann Williams (gail) Mon 27 Jan 03 16:00
I liked that you named the cornstarch goo "Robot Food," Mark. What a strange substance that is. When I was about 11 years old, I spent my summers in the Sierra Nevada where my dad ran a climbing school. He had a lot of interesting grownups for students, but most of them ignored me and my sisters. So the big challenge was to figure out things to amaze them -- yet not annoy our parents. One of my favorites was when we mixed up some cornstarch -- er, Robot Food sans food coloring -- in a Sierra Club cup and breathlessly presented it to one of the climbers, saying we had found it oozing from a crack in the granite where there was a dark stripe. He played with it for a good 15 minutes, fascinated and puzzled, and asked us additional questions. Then one of the few women students happened by (this was the late sixties, when adventure sports were still overwhelmingly male) and took a look. She knew immediately, and busted us, somewhat slyly, by saying "making gravy, girls?" I have a request, for the sequel. Someone gave me a copy of a homemade household cleaning formulas book, and I realized that a slightly older kid might find the removal of silver tarnish by use of water softener and aluminum foil, etc, magical or scientifically instructive, too. It sure had me wondering.
Mark Frauenfelder (mark) Tue 28 Jan 03 09:35
Great story, Gail! Please tell me how to remove silver tarnish using your magical method. My wife found an old silver dollar in a box and it is almost black. We'd love to make it shiny again.
Evelyn Pine (evy) Tue 28 Jan 03 09:37
The request for a sequel from my five year old, Gabe, is one using outdoors stuff, mud, branches, plants, water, seeds. Not that he doesn't want to make a Martian Volcano everyday, mind you.
a little bit (rockyshoe) Tue 28 Jan 03 10:58
must know how high the film canister is supposed to explode.
Mark Harms (murffy) Tue 28 Jan 03 18:43
Maybe you need a tighter lid that lets more gas pressure build up before popping. I haven't tried this one. I wonder if a Fuji film cannister is better than Kodak. Mark? I'd have to say the book's 9-12 age designation is more of a guideline (perhaps erring on the side of caution). It looks like younger kids can enjoy the projects safely with adult supervision. What do say, Mark? You credit your daughter, Sarina, with helping out with "honest feedback." Were there some experiments she poo-pooed?
beneath the blue suburban skies (aud) Wed 29 Jan 03 10:20
my lab partner has the flu, so though I did buy borax and white vinegar for us, we haven't gotten back to experimenting. hopefully next weekend. not sure if this is what Gail does, but I saw someone hawking a home cleaning book on TV once and they cleaned silver with a solution of warm water, salt and washingi soda, in a pan lined with aluminum foil. Have used that method a few times, winging the proportions and it works great.
Gail Ann Williams (gail) Wed 29 Jan 03 11:00
Yeah, that's it. By a guy named Haley. I'm no cleaning wiz, but I got that book as a sort of geeking household joke gift. I really want to know the science of this: place a sheet of aluminum foil on the bottom of a sink or pan 1 qt hot (not burning hot) water (enough to cover silver) 1 Tbsp water softener/washing soda (he notes that if you are in europe this is not what is called "washing soda crystals" over there -- which could do damage to silver) 1 Tbsp salt Place the silver in for 10 seconds, be sure all silver peices touch the foil and are fully covered by water. Remove, buff with a soft cloth. (On the web you find variants saying that you have to use a pan, and boil the silver and all for 2 minutes, but that doesn't seem to be the case.) There's an article on care of valuable raised pattern silverware, etc, at http://doityourself.com/clean/silver.htm mentioning this method with the boiling directive. The Haley book says to not use it with anything with stones set in it. The setting could loosen. (I'm guessing that's with glued settings only but he doesn't say). I have a bunch of questions. What's the chemical colution from salt and water softener/washing soda? How does the electrolytic process work (I think that's the term.) Why are other folk methods polishing with either salted lemon juice or a baking soda solution, since one is acid and one base? Why do you damage silver if you put it in the dishwasher touching stainless steel? It's all a mystery. But dipping into that bath and touching the foil is very cool.
Gail Ann Williams (gail) Thu 30 Jan 03 09:39
OK, I finally did the logical thing and asked in the Science conference. Great answer, I'll paraphase the points. I hope the poster drops by over here too. This experiment creates a weak battery the NaCl/Na2CO3 is the electrolyte, and the dissimilar metals are the electrodes. The oxidized silver tarnish is being reduced and the more reactive aluminum is being oxidized If enough spoons were cleaned, eventually the aluminum foil would disappear. The aluminum is providing electrons to the silver. If you cleaned enough silver there would be a white precipitate of some kind of aluminum hydroxide or carbonate precipitate ... (maybe we can figure out what that would be). <science.564.133>
Gail Ann Williams (gail) Thu 30 Jan 03 09:40
Obviously that's for older kids, but the idea that you are making a battery to clean coins, spoons or necklaces is pretty cool.
Mark Harms (murffy) Thu 30 Jan 03 10:09
That is interesting. And thanks to (jetpack) over in the science conf. I know little about chemistry.
Mark Frauenfelder (mark) Thu 30 Jan 03 11:07
Thanks Gail! I guess you can buy water softening powder at any supermarket?
Gail Ann Williams (gail) Thu 30 Jan 03 11:39
Did a little more poking while on the phone on hold. The key thing is getting the right chemicals. From http://www.steamengine.com.au/ic/faq/electrolysis.html >Pure sodium carbonate is called soda ash, and is very dangerous because >it will boil water when mixed with it, and even make a steam explosion. >Washing soda is the hydrated form of sodium carbonate (called sodium >carbonate decahydrate, it has TEN water molecules attached to one >sodium carbonate molecule!), and is 5/8 water by weight even though >it is a dry powder. The product you found at the store labeled as >detergent is not washing soda, although it has some in it. Washing soda >is a mixture of mostly sodium carbonate decahydrate with some sodium >sesquicarbonate and sodium bicarbonate in it. Go to the grocery store >or supermarket and read the labels on the washing supplies for walls and >floors. Washing soda is sold under the names of stuff like Spic 'N Span, >TSP Brand washing compound, and 20 Mule Team washing soda (not borax). If >you can't find anything that is 90%-100% washing soda (sodium carbonate >decahydrate) and/or sodium sesquicarbonate, just get some plain old Arm & >Hammer baking soda. Take 0.6 times (about 5/8) as much baking soda as >the amount of washing soda called for in the electrolyte recipe, >add just enough water to make it soupy, heat it for a few minutes while >it fizzes, then add it to the rest of the water. Baking soda is >sodium bicarbonate, which decomposes with a little heat and water into >carbon dioxide gas and sodium carbonate decahydrate.
Gail Ann Williams (gail) Thu 30 Jan 03 11:43
However, I think either washing soda or water softener would be in the laundry aisle.
Jon Lebkowsky (jonl) Fri 31 Jan 03 15:53
A new discussion has launched featuring Cory Doctorow (who's a prolific blogger via the bOING bOING blog that Mark F. created). Mark and Mark, I wanted to thank you both for bringing us this cool discussion, and let you know that you're welcome to continue!
Mark Harms (murffy) Fri 31 Jan 03 17:59
Thanks Jon. And thanks Mark.
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