I can't give you incredible specifics, but everything I've seen indicates that it's a matter of mixing the two slowly and carefully and letting them catalyze for awhile. If you cap the bottle you're using to mix it in, the fumes will cause the bottle to explode from the liberated gases before the reaction is complete. If you don't explode, you'll likely poison yourself in the relatively poorly ventilated lav. Most of them if you don't keep cool will decompose rapidly prior to completion of the reaction, spewing the mixture all over you.

Also, there aren't that many truly binary explosives, most of them require three components, although the acid is generally only a catalyst. And shaking would be a bad idea, unless you want premature detonation, which would again result in little more than a burst vessel and crap all over the inside of the lav, and a dead would-be terrorist.

Except that one that's actually sold, which consists of pouring nitroethane into a container full of tiny plastic beads and letting the nitroethane soak through.

Additionally, the components of most of these are volatile fluids that will decompose if exposed to light and will not be contained in plastic bottles, and due to that volatility need to be kept cool, and also produce lots of fumes.

Lastly, I'm pretty sure, but wouldn't be in a position to know like the head honchos at the TSA, but at least one of the components of all of the explosives one can (relatively, none of them are truly easy) easily mix are detectable by ETD machines, with the exception of TATP, which I believe is only detectable once mixed, but would be very difficult to clandestinely mix on an aircraft, given that one would require 90 or 100% hydrogen peroxide, which isn't very stable. It also takes several hours for the powder to precipitate out of the acetone and peroxide mix, and needs to be kept cool the entire time.

Thanks to Djlawman for spurring me to Google "liquid explosives" and learn about these things for myself.

If someone spends a rather long time in the lav and makes it smell of chemicals, you know something funny is going on. Of course, he's probably dead by then from the fumes..so look for guys going into lavs with two or more drink containers and a gas mask, and probably a glass bowl or flask, too.

Really the only one I'm worried about is the commercialy sold mine clearing explosive that consists of nitroethane and the aforementioned tiny plastic pellets as a sensitizer. (nitroethane is pretty darn stable without a sensitizer, most explosions without it have been caused by valve hammer effects causing a rapid rise in pressure in the container dispensing the fluid) Of course, that one needs a detonator, since it's quite stable even when mixed with the sensitizer, so if we stop making the TSA do stupid things like X-Ray shoes and look for harmless "weapons," maybe they'll be able to concentrate on finding important things like that.

IMO, good security consists of an xray of hand luggage, a WTMD, and an ETD swab of shoes and perhaps the confiscation of dark glass bottles that the owner is unwilling to drink from, if we're worried about people somehow smuggling an equal amount of acetone and a few pounds of ice onto the plane and letting them react for a few hours.

P.S. Sorry for the ramble, I'm no editor.