Natural Beekeeping International Forum

[AndyC]

I've been reading up on the home made versions of these evaporators using auto diesel glow plugs.

Hope people realise that oxalic acid cystals evaporate at 157C and breakdown at 187C.

Diesel glow plugs generally heat to bright red heat, about 950C, in a few moments so even with wiring resistance and mechanical losses are apparently far too hot for this application at 12v, unless the current is controlled in some way.

Gonna be some fried bees on the menu I reckon.

[madasafish]

I run a glowplug evaporator and have killed no bees. Despite trying on seven hives.

As the evaporator heats up from the glowplug, the oxalic sublimes , and vaporises. None remains of the suggested 2gm dose after about 90 seconds.. With no pressure to prevent vapourisation, the oxalic acid does not overheat but forms a liquid , and bubbles off.

Scare stories abound, reality is different. Don't believe what you read on the internet.

Of course if you use enough oxalic on a small surface so it binds together in lumps of acid solids and liquids, it might be different. But we are then talking lots of grams not 2..

[AndyC]

Did you spec the glow plug to run at 12v or just trust to luck?

[madasafish]

I bought a Champion CH154 for a TOYOTA 2.4D HIACE. £2.75 delivered ebay..

Old style 12V diesel so lower temps..

see http://tinyurl.com/grh89lr for similar.


Luck? Well I trained in physics so know a little electricity and electronics..

[AndyC]

Ok understood thanks.

[zaunreiter]

Oxamat Mini for Warré hives:

https://www.youtube.com/watch?v=wdsbClU0y6I

Uses a car battery and a headlamp bulb (H4 55/60 W) as a heat source. The fan distributes the vapor throughout the hive.