Would a hair-gel bomb actually work?

On Dave Farber's Interesting People list, a chemistry grad student posts his analysis of the implausibility of mixing acetone peroxides in and airplane out of ingredients smuggled aboard (his caveat: "I'm working entirely off of news reported by people who
don't know the difference between soft drinks and nail polish remover,
but the information I've seen has the taste of being real.")

What's really amazing is when he gets into why seizing liquids won't keep explosives off of planes, describing how you could make undetectable thermit canes, exploding baby-powder, deadly laptop batteries -- even explosive clothes.

A mix of H2O2 and H2SO4, commonly called "piranha bath", is used in
orgo labs around the world for cleaning the last traces out of organic
material out of glassware when you need it *really* clean -- thus,
many people who work around organic labs are familiar with it. When
you mix it, it heats like mad, which is a common thing when you mix
concentrated sulfuric acid with anything. It is very easy to end up
with a spattering mess. You don't want to be around the stuff in
general. Here, have a look at a typical warning list from a lab about
the stuff.

Now you may protest "but terrorists who are willing to commit suicide
aren't going to be deterred by being injured while mixing their
precursor chemicals!" -- but of course, determination isn't the issue
here, getting the thing done well enough to make the plane go boom is
the issue. There is also the small matter of explaining to the guy
next to you what you're doing, or doing it in a tiny airplane bathroom
while the plane jitters about.

Now, they could of course mix up their oxidizer in advance, but then
finding a container to keep the stuff in that isn't going to melt is a
bit of an issue. The stuff reacts violently with *everything*. You're
not going to keep piranha bath in a shampoo bottle -- not unless the
shampoo bottle was engineered by James Bond's Q. Glass would be most
appropriate, assuming that you could find a way to seal it that
wouldn't be eaten.


(via Schneier)