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What grinds your gears?

Discussion in 'The Lounge' started by retrofit, Nov 20, 2016.

  1. GeoffR

    GeoffR Well-Known Member

    Yea, the one that makes you go blind isn’t recommended for drinking.
     
  2. peterba

    peterba Well-Known Member

    Yes, it occurred to me that the Isopropyl might be a little too vicious.

    Anyway, I tried some bicarb (I realise that, in my post #9637, I wrote "baking soda" - I should have written bicarbonate of soda) on an old rubbery-coated camera which had been stuck in a drawer for years, and had got very sticky. The first application of the paste started to work, but the result was somewhat hit-and-miss. I tried a second application, which worked rather well. I simply rubbed the paste onto the camera by hand, let it stand for a couple of minutes, and cleaned it off - then repeat. I've no idea whether this is the best method, but that's what I tried. @Catriona, you might want to try this on your torch. :)
     
    Catriona likes this.
  3. Catriona

    Catriona Well-Known Member

    Thank you! I will try it.
     
  4. spinno

    spinno Well-Known Member

    Are you sure that's alcohol?
     
  5. peterba

    peterba Well-Known Member

    Remember to avoid getting moisture into the electrical areas! I took the paste off with a slightly damp cloth.
     
    Catriona likes this.
  6. GeoffR

    GeoffR Well-Known Member

    Isopropyl can cause blindness I believe, anyway I wouldn’t take the chance
     
  7. steveandthedogs

    steveandthedogs Well-Known Member

    I thought baking soda was bicarb? Baking powder is bicarb in flour.
    How about Borax? These days that is a mixture of bicarb and carbonate.

    S
     
  8. peterba

    peterba Well-Known Member

    Yes - apologies, Steve. I think baking soda is the US term for what we call bicarbonate of soda (bicarb), while baking powder has other additives (cornflour, IIRC?).

    Anyway, I was referring to bicarbonate of soda. Sorry for the confusion. :)
     
  9. dangie

    dangie Senior Knobhead

    Buy a new torch :)
     
    peterba and Catriona like this.
  10. Footloose

    Footloose Well-Known Member

    Or, an excellent (excuse) whoops! I mean highly justifiable reason for buying a new camera? :rolleyes:;)
     
    Last edited: Sep 6, 2021
  11. Learning

    Learning Ethelred the Ill-Named

    Dozens of them. The potable alcohol is ethanol (ethyl alcohol). The first three of the family are methyl alcohol, ethyl alcohol, propyl alcohol.
    Basically a hydrogen atom is replaced by an OH group in a paraffin molecule. It gets complicated because once you get above ethane there is a choice of where the OH group is located. It gets even more complicated because the chain of carbon atoms in the higher paraffins can be forked. It gets worse; it is often possible to replace more than one hydrogen atom with an OH group so as to give double or triple alcohols. Glycol which is used as an engine coolant is an example of a double alcohol. I hated organic chemistry but remember bits of it. I may have got some of the above wrong, but its certainly correct that only ethyl alcohol is fit to drink and the whole family of alcohols is complicated.
    No doubt @Petrochemist could write us a long essay on the topic.
     
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  12. PeteRob

    PeteRob Well-Known Member

    From memory, the most common alcohol that causes blindness is methanol. It is extremely dangerous. That is why methylated spirit (90% ethanol, 10% methanol) has additive to make it noxious.

    Back in 1985 there was an enormous scandal related to use of antifreeze in wine https://en.wikipedia.org/wiki/1985_diethylene_glycol_wine_scandal
     
  13. Petrochemist

    Petrochemist Well-Known Member

    I could, but I'll try to resist.
    I didn't spot any real errors in the above, but the positional factor you mention means there are two propanols, so you could say the first four are methyl alcohol, ethyl alcohol, propyl alcohol. Oh and there are much more than just dozens all together, though I've never met more than about a dozen. :)

    I have to admit I didn't like organic chemistry at uni. There seemed to be far to much emphasis on reaction pathways (movement of electrons within the compound) which have never been useful since.
     
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  14. dream_police

    dream_police Well-Known Member

    I have a feeling that Martin may have been joking.;)
     
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  15. dangie

    dangie Senior Knobhead

    I didn’t spot any errors either. Not surprising really as I didn’t understand a word of it :)
     
    Zou, Learning, MJB and 1 other person like this.
  16. Petrochemist

    Petrochemist Well-Known Member

    You need a justifiable reason?
    I brought a Pentax Q last week so I could adapt a d-mount lens that came as part of a job lot (well that was the final straw I'd wanted one for years)
    Then over the weekend I added a cine camera for the two lenses that came with it...
     
  17. Learning

    Learning Ethelred the Ill-Named

    Don't worry about it if you stick to legal sources of booze. By the way I only did Chemistry to A level which I surprisingly passed quite well. My favourite subjects were, and are, physics and mathematics. Application of computer science within engineering eventually became my job. I also have an amateur interest in geology and gained a couple of half credits in that from Open University as part of an accidental BA..
    My dozens of alcohols is way under. Theoretically there must be millions of them. I wonder how many naturally exist and how many more have been synthesised
    Glycol has also been used illegally by gardeners to reduce their feral cat population. Although I hate cats I find that use very distasteful. It ain't British; is it?

    .
     
  18. DaveS

    DaveS Well-Known Member

    Methanol is metabolised to methanal, aka formaldehyde, which does horrible things to just about all tissues, but especially the eyes, hence blindness.
    Ethan-1,2,-diol, aka ethylene glycol is metabolised to oxalic acid, which again is toxic.
    Propan-1,2,3-triol is relatively non toxic, it's better known as glycerol.
     
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  19. DaveS

    DaveS Well-Known Member

    Although retired, I have been a synthetic organic chemist.
    How competent is open to question.
     
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  20. Learning

    Learning Ethelred the Ill-Named

    You know more about it than me. (or should that be 'than I'). I scraped through English at O level at my second attempt.
     
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