Gas Vapourizer

[wightbees]

I was watching this earlier

https://www.youtube.com/watch?v=timAIlH_1OQ

Fogger is easy to make, I have one but there's some critics here lol...

 

[Eyeman]

Im pleased it turned out ok, but bamboozled you are treating with oa when brood is present, unless you are planning several treatments

Plan is 3 treatments with a 4-5 day interval. Did the same last year with the nucs late summer (using the varrox) and got minimal drop with my winter treatment.

 

[protheroe]

Having never used a varrox but have seen a video of it vapourisiing oxalic,it looked like an explosion of vapour that would cover everything in the hive.do you think a larger dose of oxalic is needed for the same coverage with the gas vapouriser and its stream of vapour.

 

[Eyeman]

I'm keeping an eye on you, eyeman.........
I did eight hives last night, it took over an hour and I nearly ran out of daylight

Let you know how tomorrows mammoth session goes. I'm quite looking forward to it. Wish I could have said the same when I was using the varrox- glad to have left all that fiddling around now I've got what appears to be the perfect device for my number of hives and apiaries.

 

[Eyeman]

Having never used a varrox but have seen a video of it vapourisiing oxalic,it looked like an explosion of vapour that would cover everything in the hive.do you think a larger dose of oxalic is needed for the same coverage with the gas vapouriser and its stream of vapour.

When I was using the varrox under the OMF some of the OA condenses on the OMF and is seen on the inspection tray at the next check.


So I ended up increasing the dose of OA to compensate.
I'm happy with how the stream of vapour from the new vaporiser behaves when introduced through the crown board. It quickly comes out through all the cracks and crannies at the bottom of the hive so no concern about good coverage.
I'm using 1g for 6F nucs and single nationals and 2g for double nationals and 14x12's.

 

[Eyeman]

I vaped 48 nucs yesterday with the blow torch sublimator.
Here is some feedback.
1. Pre-heat for 2 minutes on medium flame then reduce to low flame during treatment
2. I used 1/4 tsp OA per nuc.
3. You hear the OA 'boil' 5 seconds after placing it in the chamber and vapour appears 5 seconds later.
4. Main vapour last approx 30 seconds from inserting OA
5. Each of my apiary sites have 10 double nucs with a few single's scattered around.
6. Nucs were treated through the crown board. The roof placed on ther CB's stopped CB movement during treatment. Picture shows 3x 3 frame double nucs.
7. I was able to treat in a 'conveyor belt' fashion so 10 nucs could be treated in less than 10 minutes.
8. The device is light enough to support itself during treatment (It did put some pressure on the joints so I would recommend using something to support the gaz canister end) so you can move away to avoid the inital vapour cloud. As treatment last 30 seconds I found that keeping hold of the device was simpler. Whilst standing you can hold it in one hand while you get the next dose of OA ready with your other hand


Problems
1. The fan on the device stopped working twice ! It is easy to accidentally switch the fan off when holding the device. If the fan is switched off during treatment vapour condenses on the fan and causes it to sieze. The condensed OA can be scrapped off the fan but it can take a while.
I recommend switching the fan on before inserting the OA and keeping the fan running during the treatment session. At the end of the treatment session turn off the flame and put water in the chamber and allow it to run down the distal tube- this will cool the chamber and tube and remove any residual OA. Then you can switch off the fan.

2. Occasional blowback of vapour through the fan- despite the fan being on. This didn't appear to affect the running of the fan unless I accidentally switched in off then it wouldn't start again until I cleaned it out. Not sure how the device would cope with 2g of OA when I get round to treating my double nationals and 14x12's. I may need to do x2 1g treatments if a problem occurs.

I've upload a video showing the stream of vapour with 1g of OA
https://youtu.be/ixZyaYF_jKU

 

[rook66]

Thanks for the report and video. So it is not necesary to use oa tablets.

 

[Eyeman]

Thanks for the report and video. So it is not necesary to use oa tablets.

Bog standard crystals work fine.
Plenty of time to get the cover on- any initial vapour that comes off is just the water boiling off. The OA takes around 10 sec to start sublimating and the vapour to start pouring out.
I was rather impressed by the force of the vapour trail- plenty sufficient to fill the hive and cover all surfaces.

 

[maddydog]

Adapted mine in a similar fashion to eyeman's.

Much better with a shortened pipe. I have accidentally partially melted the aluminium piece that points at 45' to the flame! I'm surprised yours hasn't done the same Eyeman as they look a similar distance away?

I've since removed it and rivetted it pointing the other way at the end of the tube to give the whole thing more support.

Much happier with it now than when I first got it

 

[Eyeman]

Adapted mine in a similar fashion to eyeman's.

Much better with a shortened pipe. I have accidentally partially melted the aluminium piece that points at 45' to the flame! I'm surprised yours hasn't done the same Eyeman as they look a similar distance away?

I've since removed it and rivetted it pointing the other way at the end of the tube to give the whole thing more support.

Much happier with it now than when I first got it

The video was after I'd treated the 48 nucs and the aluminium arm looks unaffected by the flame. I did 10 nucs without switching the flame off so it must have got pretty hot. Did keep the flame on minimum during treatment.
Glad you've got yours up and running. Post some feedback on whether you've had any blowback through the fan and whether it can cope with 2g of OA?
I've been looking for a replacement fan as this and the switch are the things that are likely to go first- seen one on ebay for £3.60 for x2 fans- but will need to take mine apart to check they are compatible.
Next session on Monday- should be more straight forward as all the crown boards on the nucs are already set up for the vaporizer. Will try not to accidentally switch the fan off during treatment next time.

 

[maddydog]

Weird that mine melted the aluminium and yours hasn't? Didn't have it on full blast either, maybe 2/3rds at most.

Probably takes a preheat of 3-4 mins then it happily does 2g and chucks vapour out at a good rate. My plan was to vape through the entrance but it has proven problematic on the underfloor entrances. I'm going to make a crownboard like yours and vape from above.

 

[maddydog]

Yeah, a decent gust does seem to overwhelm the fan. My guess it needs far more puff than that piddly one. I'm no engineer so I'm not sure whether stacked fans would work? Only a matter of time before the switch snaps off...

 

[Beefriendly]

Take a leaf out of the sublimox idea. Closed heated chamber, drop OA into sealed chamber with nozzle and sublimation creates it's own gas jet. No need for fans.
Just a thought.

 

[Eyeman]

Take a leaf out of the sublimox idea. Closed heated chamber, drop OA into sealed chamber with nozzle and sublimation creates it's own gas jet. No need for fans.
Just a thought.

Yes a good idea.
Could block off the rear chamber hole to the fan (not sure with what?)and see if it works like the sublimator.
What's the current opinion on temperature control?
Clearly the blow torch heats the chamber to god knows what temperature- the device clearly kicks out vapour but is the vapour just oxalic acid or formic acid/carbon monoxide????.

 

[Eyeman]

Yeah, a decent gust does seem to overwhelm the fan. My guess it needs far more puff than that piddly one. I'm no engineer so I'm not sure whether stacked fans would work? Only a matter of time before the switch snaps off...

Did you find that 2g overwhelms the fan more that 1g OA? I did get a few blowbacks with 1g but it didn't cause the fan to seize up.

 

[maddydog]

Did you find that 2g overwhelms the fan more that 1g OA? I did get a few blowbacks with 1g but it didn't cause the fan to seize up.

2g was fine and produces a nice steady stream. Whether it's oxalic or as you say, formic/carbon monoxide is anyone's guess

 

[Beefriendly]

Yes a good idea.
Could block off the rear chamber hole to the fan (not sure with what?)and see if it works like the sublimator.
What's the current opinion on temperature control?
Clearly the blow torch heats the chamber to god knows what temperature- the device clearly kicks out vapour but is the vapour just oxalic acid or formic acid/carbon monoxide????.

High temp is good. Sublimox has removable cap which you fill with Apibioxal without additives whilst keeping it upside down. When you want to use it you invert it so the crystals fall into the already heated chamber. Simple but effective.

 

[Eyeman]

High temp is good.

So all this worry about producing formic acid & CO when the temperature gets above a certain level is nothing to worry about?
My thought was that the OA would already have sublimated as the lower temperature so there would be no OA left to heat up further?
I thought the sublimox was set to work at the 'optimum' temperature for OA sublimation? So why do you say high temperature is good?

 

[maddydog]

Yes a good idea.
Could block off the rear chamber hole to the fan (not sure with what?)and see if it works like the sublimator.
What's the current opinion on temperature control?
Clearly the blow torch heats the chamber to god knows what temperature- the device clearly kicks out vapour but is the vapour just oxalic acid or formic acid/carbon monoxide????.

My concern is that without a fan as the oxalic rapidly sublimates it'll push through the gaps in the cover. What it needs is a set of bellows!

 

[Beefriendly]

You need 160 oC for OA to sublimate and only if any is left and temp gets to 190 do you get formic and co2.