For the purpose of fumigating comb, there won't be much difference in the
utility of 80% vs higher concentrations.
The vapor pressure of acetic acid is roughly the same as that for water (10
mm Hg for acetic acid vs 13.5 mm Hg for water) at room temperature.
So the two will tend to evaporate at about the same rate, and the
concentration will remain fairly consistent.
I'd buy whatever I can find cheaply, and put the savings into pallet wrap to
tightly seal the stacks of supers, and keep the vapors in.
Remember to get a good seal on the underside of the bottom box, as acetic
acid vapors are heavier than air.
One mole of a gas will fill 22.4 liters (just over half a deep), and Acetic
is 60 grams per mole.
So, those using 80% acetic will need to start with 125% of the calculated
amount of solution.
Using 99%, you'd only need 101% of the calculated amount.
But who are we kidding here? No one is going to sit down and work out a
Raoult equation for the vaporizing solution, everyone is going to use "more
than enough".
I remember Andony Melathopoulos giving a talk in the past few years about a
study they ran comparing Acetic, Heat, and E-Beam.
I am pretty sure he used 80% acetic.
E-Beam won hands-down, of course, while heat and acetic were equally less
effective, but they each still had measureable impact.
One thing I remember from Andony's talk is that he described the Canadian
strains of Nosema ceranae as not being as persistent through the summer as
we have seen in the USA.
I used to solder wires to button-cell battery holders, put a zinc-oxide
battery into each holder, and toss them into the bottom box of each stack.
Then, after a few hours, I'd put a resistor and a milliamp meter across the
leads, and measure the current after a bit. Zero current (or zero voltage
drop across the resistor) means near-zero oxygen inside, as zinc-oxide
"hearing-aid" batteries need air to make juice. Near-zero oxygen means a
good fumigation. Maybe a little too obsessive compulsive for most, but when
you do anything to a barnfull of supers, you want to be able to have
metrics.
***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html
|
