OA vape 5 days vs. 7 days apart - what do you recommend? - Page 3
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  1. #41
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    Default Re: OA vape 5 days vs. 7 days apart - what do you recommend?

    Quote Originally Posted by unstunghero View Post
    Steam, definition, the vapor into which water is converted when heated, forming a white mist of minute water droplets in the air.
    That's an everyday dictionary description of the term 'steam'. Suggest you research further - try engineering/ science sources.
    LJ
    A Heretics Guide to Beekeeping http://heretics-guide.atwebpages.com/

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  3. #42
    Join Date
    Apr 2019
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    Northeast PA
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    Default Re: OA vape 5 days vs. 7 days apart - what do you recommend?

    Quote Originally Posted by davemal View Post
    These videos I made recently regarding OAV injected into the bottom vs top of a colony might be of interest to this thread. The second one shows the crystals that form.

    https://www.youtube.com/watch?v=K5dk52VMUB8
    https://www.youtube.com/watch?v=qpTjPWW9Pe8
    This was informative.

    In your opinion, is there any risk of contamination from having honey supers on the hive?

  4. #43
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    Mar 2012
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    Catskills, Delaware Cty, New York, USA
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    1,800

    Default Re: OA vape 5 days vs. 7 days apart - what do you recommend?

    Quote Originally Posted by little_john View Post
    'Sublimated' simply means changing from one state (solid) into another (gaseous) without passing through the intermediate state (liquid).

    So - with water we have: ICE > WATER > STEAM.

    But with OA we have: SOLID > VAPOUR (no intermediate state)

    Now steam isn't that white stuff we see clouds of, when a kettle is left to boil over - the steam is the first inch or so of invisible gas which exists at the spout. As soon as it cools a little, it changes back to it's previous state and becomes visible again as a white cloud. Now in everyday language we call that white stuff 'steam' but strictly speaking it isn't - it's become water again, but now in a microfine liquid state.

    Oxalic Acid when heated sublimates into a gaseous state, but is similar to water insomuch as that gas (or vapour) is invisible. Just as with water, as soon as it cools a little, it reverts to it's previous state - only this time not to a liquid (because it doesn't have a liquid state), but directly back to a solid - and thus becomes visible once again, but now as a white cloud of micro-fine crystalline dust.

    The whole point of the exercise is to turn rather large crystals of a damp, clumpy organic acid into an ultra lightweight dust which can then spread out over a relatively large area leaving it with a thin covering of OA. Turning it into a gaseous state for a few thousandths of a second is an ideal way of doing this, as one of the properties of gases (going back to Chemistry 101 here !) is that they expand to fit the container they're held in. This occurs because each molecule of gas has kinetic energy which causes it to bounce off neighbouring gaseous molecules, and so the gas spreads outwards accordingly.

    So - in the case of Oxalic Acid vapour which cools back down below it's sublimation point - which will occur just a few millimetres away from the hot surface which initially caused it to change it's state - the micro-fine crystals which are formed will be one molecule of OA in size.

    But the story doesn't end there. Two further things will happen: firstly, solid objects always attract each other by gravitational forces - this can readily be seen in space with planetary systems, and is how we can walk around on the Earth's surface rather than levitate up into the heavens.
    With OA, the micro-fine crystals just generated will begin to attract each other and thus become larger.

    Secondly, you'll be aware that Oxalic Acid is supplied as a Dihydrate - meaning that there are water molecules attached to the OA crystals. (Yes, when you purchase OA, you're also paying for water !)

    Now the OA micro-fine crystals whiuch were formed by vapourisation (a process which will have stripped-off it's 'Dihydrate' water molecules) are now hygroscopic, and so will gradually attract moisture from the atmosphere to form slightly larger Oxalic Acid Dihydrate crystals, but in a significantly smaller crystalline form than when the process was first started.

    Which is why I much prefer the abbreviation VOA - Vapourised (past tense) Oxalic Acid, rather than OAV - Oxalic Acid Vapour or Vapourisation - the latter implying that the vapour continues to exist - which it doesn't - it only exists as a vapour for a few milliseconds. In the case of a Band Heater Vapouriser, the vapour only ever exists within the equipment, not outside of it.

    ... end of chemistry lecture ...

    Hope this has been helpful.
    LJ
    Yes, thank you.
    Proverbs 16:24

  5. #44
    Join Date
    Apr 2019
    Location
    Northeast PA
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    306

    Default Re: OA vape 5 days vs. 7 days apart - what do you recommend?

    I've posted a new thread on this subject of OA vape with honey supers present.

    In conclusion, I think we're being far too cautious about treating hives with OAV with supers present.


    Based on my back of the envelope calculations, 1 lb of honey from a full round of OAV treatments (2 brood chambers and 1 honey super) will contain, at the most, 20-40mg of oxalic acid. Based on a quick google search, oxalic acid content of a bowl of grits, a cup of almonds, or a mixed salad is 100+mg of oxalic acid.

    Therefore, I cannot conclude that OAV treatment with honey supers are a particularly strong health risk. Especially if it's clear that eating a mixed salad with almonds will result in 10X + the amount of OA from the total amount of OA in 1 pound of honey.

    Seems likely to me that even consuming half a gram of oxalic acid mixed in water would probably not cause severe health effects. There's little chance, in my opinion, that OA concentration in 1 pound of honey would ever increase to 100mg - the same amount found in a mixed salad with almonds.

    Therefore, I cannot conclude that even the most aggressive treatment of Oxalic acid vaporization would render honey remotely unsafe for human consumption.
    Last edited by username00101; 08-06-2019 at 02:41 PM.

  6. #45
    Join Date
    Feb 2012
    Location
    West Bath, Maine, United States
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    2,491

    Default Re: OA vape 5 days vs. 7 days apart - what do you recommend?

    You are confusing practicality with reality. OAV had a history of decades long use in Europe, however was a registered pesticide in the US from 1957.

    https://www.dadant.com/epa-okays-oxa...-mite-control/ for a history of authorizaation.

    For a EPA reg; https://www3.epa.gov/pesticides/chem...1-20151013.pdf

    Anybody got a later version?
    It is not true that you cannot teach an old dog new tricks.
    They can learn them, they just can't do them.

  7. #46
    Join Date
    Mar 2015
    Location
    Frederick, MD
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    64

    Default Re: OA vape 5 days vs. 7 days apart - what do you recommend?

    Quote Originally Posted by username00101 View Post
    This was informative.

    In your opinion, is there any risk of contamination from having honey supers on the hive?
    I do not do OAV with supers on.

  8. #47
    Join Date
    Jun 2015
    Location
    Litchfield, Ct, USA
    Posts
    254

    Default Re: OA vape 5 days vs. 7 days apart - what do you recommend?

    Quote Originally Posted by username00101 View Post
    In conclusion, I think we're being far too cautious about treating hives with OAV with supers present.


    Based on my back of the envelope calculations, 1 lb of honey from a full round of OAV treatments (2 brood chambers and 1 honey super) will contain, at the most, 20-40mg of oxalic acid. Based on a quick google search, oxalic acid content of a bowl of grits, a cup of almonds, or a mixed salad is 100+mg of oxalic acid.
    A lot of unhealthy things are in our foods, but we certainly don't want to add to them if we can avoid it.

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