Chemistry

Using a plastic bottle label as a built-in etch resist

Using a plastic bottle label as a built-in etch resist

One of our most-trafficked original tutorials over the past couple of years has been this simple trick for etching designs on glass bottles by using the label itself as a stencil. It’s a quick, satisfying, inexpensive project that yields long-lasting results with common equipment. In the process of porting the original blog post to our new Make: Projects platform, I took the opportunity to revisit the idea, updating the old images and adding a couple of helpful details, all of which was refreshingly easy using the new interface. Check it out.

New in the Maker Shed: Cooking for Geeks

New in the Maker Shed: Cooking for Geeks

I’m very happy to announce the availability of Jeff Potter’s Cooking for Geeks in the Maker Shed. I met Jeff while he was making ice cream with liquid nitrogen at a party sometime last year. I don’t think I’ve been more excited about a cookbook in my life. If you were ever curious about what you eat beyond the ingredients and recipe, then Cooking for Geeks is for you.

Maker Birthdays:  Stephanie Kwolek

Maker Birthdays: Stephanie Kwolek

Born on this date in 1923 in the Pittsburgh suburb of New Kensington, Stephanie Louise Kwolek (Wikipedia) graduated from Carnegie Mellon in 1946. She would go on, starting in 1964, to discover the remarkable properties of paraphenylene terephtalamide polymers, research which would culminate in 1971 with the advent of Kevlar (Wikipedia), an entirely new field of polymer chemistry, and the countless remarkable applications thereof we now enjoy. Today Dr. Kwolek is 87. Happy Birthday!

How-To: Levitate a pencil lead

Prolific, anonymous YouTube DIY science guru NurdRage, who in the past has brought us instructions for synthesizing trichlorophenyl oxalate (TCPO) and instructions for using it to make homemade glowstickx, presents this cool video and corresponding Instructable showing how to demonstrate diamagnetic levitation using common pencil lead instead of the usual (and expensive) pyrolytic graphite.

How-To: Restore the color of old Lego bricks

How-To: Restore the color of old Lego bricks

Turns out the yellowing of old ABS plastic is due to degradation of bromine-containing fire retardants which are added to the plastic during manufacture, which release elemental bromine, causing the yellow color. Shining UV light on the gel accelerates the decomposition of the fragile oxygen-oxygen bond in the peroxides it contains, generating reactive hydroxyl radicals which scavenge the free or loosely-bound bromine in the plastic that causes discoloration.