Top Down Oxalic Vaporization

[Ray Bayless]

I did some more reading and wanted to bounce what I found off you guys. A European study stated that vaporization with oxalic acid is most effective when applied from the upper chamber. I was thinking of building a small spacer with a hole to apply the vapor. Also, the study said that if you are using a propane heated vaporizer that you have to account for the material that stays in the pipe so more than 2g is needed to properly treat the colony.
Has anyone else seen or heard this information?

[tefer2]

Hot air rises, don't understand how it will get to the bottom!

[Robo]

I guess it could work.  Just like a house fire, if you get enough smoke it will fill a room to the floor.  But I'd like to understand their rationale as to why it is better.

[Ray Bayless]

http://www.google.com/url?sa=t&source=web&cd=8&ved=0CEwQFjAH&url=http%3A%2F%2Fwww.fifebeekeepers.co.uk%2Fsublimation.pdf&ei=rvgiUar-Ioa0yQGa-YCoBQ&usg=AFQjCNH2MfqpFauNJbDhx-S1ulaV0yphmw

I don't understand the benefits either but this link is where I read about it. This link is a.pdf document.  They state that the oxalic vapor condenses to crystals and would adhere to the upper portions of the hive. Unlike smoke the vapor does have mass so gravity would help distribute the crystals downward. I'll look some more.
They also state that the upper delivery seems more effective. I was wondering how they determine the amount of extra acid that has to be used when the application is performed with the propane powered units.
The vaporizer I built is made fron 3/8in stainless pipe and 1/4in sst tubing.

[danno]

If everything topside was sealed the vapor would have no where to go but down.  I dont see any advantage to it though.   When burned in the bottom I know it fills the hive because I see it seeping out of any cracks up top and in the middle