Addenda

Make a thermal carafe out of leftover parts and trash!

Several readers sent me feedback on the slapdash thermal carafe project. Here is some of what they said.

Michael wrote to say that paint thinner works well when you need to remove expandy foam from places where it unintentionally ended up. This works best while the foam is still uncured.

However, paint thinner can be destructive and irritating to things like paint. And skin. Be sure that applying paint thinner is preferable to leaving the foam where it is for the surface in question.

Dr. Rick wrote to say that there is another brand of expandy foam (update: that link is dead/product discontinued) that is based on latex, so it cleans up easier (and expands slower). I haven't tried this product, but you might want to.

Several readers expressed concerns with reusing plastic bottles and heating them up. Some people opine that plastic can release chemicals as it ages or when heated that are toxic or at least bad-tasting.

My Web research into this matter is somewhat inconclusive. I found several sites that suggest it is fairly safe to reuse and heat plastic bottles; however, it is not clear how broadly the facts apply. I suppose it depends on exactly what type of bottle you use.

Here are the sites I found:

• http://www.plasticsmythbuster.org/
• http://debris.com/journal/832
• http://www.snopes.com/medical/toxins/petbottles.asp
• http://www.snopes.com/medical/toxins/cookplastic.asp

I don't know whether it's a great idea to reuse and heat plastic or not. But by all means, if you have any reservations, simply substitute a glass bottle or a metal bottle (if you can find one) in the project for the inner bottle.

Both glass and metal will have more mass than the thin plastic bottle I used, so it's possible that there will be more of an initial drop in temperature when a hot liquid is added to the carafe. This can be counteracted by pre-heating the vessel with hot tap water for a few minutes before putting your coffee inside.

Metal will conduct heat better than glass, so it might not retain heat quite as well. On the other hand, glass is more fragile.

If anyone tries using metal or glass instead of plastic for the inner bottle, drop me a line (my email address is below). Let me know how it worked out.