Friday, 21 January 2011

Polymerisation / Procrastination

So, I had a few boring little online chores to do this afternoon - setting up bill payments, checking postal addresses... boring boring boring
Therefore, obviously, as soon as I sat down with my laptop I was filled with a sudden urge to know about the white residue from superglue that I mentioned in my last post. Having  managed to not think about this for three weeks, suddenly the research could be put off no longer for I would die if I did not find out.
Never let it be said I don't procrastinate properly

Turns out it's quite simple really: Superglue gives off vapours as it sets, these vapours react in the presence of moisture to make white crystals. These white crystals are the residue.
But, well, it's me. I want to know the real science*. Come along for the ride:
Superglue is basically ethyl cyanoacrylate (ECA). Cyanacrylate glues work because they polymerise in the presence of very small amounts of water (the water is a catalyst. It doesn't join in, but it encourages the  esters to go play) - such as water vapour in the atmosphere. When they polymerise, they solidify, and form long strongly bonded chains, binding your surfaces together.
However, this polymerisation is an exothermic reaction - it gives off heat into the surrounding atmosphere. Being heated causes small amounts of the cyanoacrylate to vaporise. In the open air, that's fine, because the vaporised molecules just disperse and your craft projects will be safe. But if you pack away your project to soon after gluing it together, the molecules are effectively trapped. As they cool they too will react if there is any moisture around (such as in fingerprints on your project), polymerise and solidify into white crystals - seen as the white residue ruining your project.
According to CSI this method can also be used to pick up fingerprints at a crime scene, though personally I can't help but think there must be easier ways... like with talcum powder...

Anywho - with regards to craft projects, clearly prevention is better than cure, and you're best to leave your project out for a few hours / overnight before you tidy it away to make sure the glue has fully gone off (cyanoacrylates set solid in a few seconds, but the  reaction takes a few hours to fully complete).
You can remove the residue with acetone (nail varnish remover) but obviously that may well bugger up the finish on your project too. If you're careful you can scrape off the residue with a  blunt object - like a fingernail or lollipop stick - but it's an imprecise art

Still, you can take solace in knowing exactly what the stuff is. Hurrah.
Nerdy Noodle xxx

*For purposes of clarification - I have had to guess at a bit of the science. It seems the craft nerds out there don't care why the residue happens, and the science nerds don't care about superglue in this level of detail. From what I can glean, with my limited science knowledge, this is what happens. It may all be completely wrong.

Tuesday, 4 January 2011

Handmade Horses

I am the sort of slightly boring fuddy-duddy aunt who buys books for Christmas. For this I can only apologise to my niece & nephew, and assure them that I'm not being dull on purpose - I actually buy them because I really like them, but cannot be seen having hundreds of kiddies picture books around the house lest people think I'm going mad / getting broody / living in some kind of alternate London where I can afford a house with storage space.
A couple of years ago I brought Who Are You, Stripy Horse? - a  philosophical piece about the nature of identity (The stripy horse wants to know what his name is, a perfectly respectable question and one I have pondered on many a post-rum morning. So he journeys around the shop trying to find out, and on the way he learns that you cannot be defined by what others tell you you are, but that your experiences and friends will help you see your strengths and skills so that you can define yourself. That, and writing your name (and maybe a return address) on some kind of label to find in the morning is a useful trick) for Boo's birthday, which she was distinctly unimpressed about.
Fortunately I'm not an entirely crap aunt and had anticipated this, so had made her a sockie stripy horse to go with the book (this was before the book got turned into a series and all sorts of character toys became available for purchase) which she was interested in for nearly a whole 2 minutes - pretty good going for a toddler unwrapping birthday presents, eh?
Given this outstanding success, i decided to return to the stripy horse theme this Christmas, crafting a gift for the daughter of the woman who manages mine n' Boy's favourite restaurant for dinner hour catch-ups - Sapori, where the lovely manager always plies us with free drinkies. We end up there about once a  week, simply because the food is tasty (I recommend the Penne Gorgonzola for any veggies), service friendly, value good and atmosphere lovely. Can't really fault that, can you? especially in tourist central.
Anyway, i decided that a little thankyou was on the cards, so made a red n white version of stripy horse for her little one. No word yet on whether the successful of original horse was repeated though... hmm...
oh well, win some lose some
Noodle x