# A Non-Inverting Band-Heater Vapouriser



## little_john (Aug 4, 2014)

Well - Johno has pretty-much cracked a DIY version of the Sublimox/ProVap design, and it's very hard to imagine this being further improved upon. 

However, I thought there might be some mileage in developing a Non-Inverting Band-Heater Vapouriser which could sit on top of the Crown Board (inner cover) - perhaps even with the operator just pressing a button and walking away.

I can see two possible advantages with such a press-button non-inverting design: firstly, there would no longer be any need to get 'up close and personal' with any Oxalic Acid dust (not that I've personally had any problems in this regard with Johno's design) - for this type of applicator could be operated remotely - from 10, 20 feet away - or even from within the next field if you're really paranoid; and secondly there would be no need to stand there like a lemon holding the applicator while it performs it's magic - indeed, with a timer added it would then be possible to automate the process such that it does indeed simply become a case of 'pressing a button, and walking away'.

There's a third advantage for myself: at 6'4" I invariably need to stoop when using a hand-held inverting band-heater vapouriser - depending on the hive height, of course - and I'd really like to eliminate that.

There is, of course, one major disadvantage of the 'cold > hot > back to cold again' sequence of the Varrox protocol in that it's very much slower than that of the inverting band-heater design. On initial testing I found this to be somewhere around 9 minutes from cold to cold - but as these non-inverting units promise to be insanely cheap to make - it could well become cost-effective for several units to be made and then operated at the same time (perhaps on the Master-Slave principle ?). But - for anyone interested in this approach, please DO be aware from the outset of this limitation.

Johno has discovered that injecting OA dust at or near the top of the hive is preferable to dosing from the bottom - so for now I'm sticking with this principle - and the lower operating temperature of this design means that construction can be far less demanding for the DIY-er. Ok, enough chat ...


Here's a sketch of the basic concept:

 

The narrow-bore delivery tube has a ID of 4mm and extends upwards inside the can by 25mm (1 inch), and protrudes downwards until flush with the base-plate, which enables the assembly to then be slid into position over the feed-hole in the Crown Board (inner cover).
The prototype 36mm OD brass 'reaction vessel' I'm using is fitted with a 150W Band-Heater - which will be replaced by 28mm copper fittings and a 120W Band-Heater providing this trial shows some promise. A standard (and therefore low cost) demi-john cork will fit perfectly into a 28mm fitting - but as a bung for this 36mm tube would cost as much as a PID controller (crazy, or what ?), I've made a simple weighted gravity closure thusly:

 

So - onto the prototype build itself ...

*Bearing in mind that this is still very much at the experimental stage* - here's the woodwork of the first prototype rig:



I've fitted a heatshield to protect the controller, which is probably unnecessary, but rather safe than sorry ...

And a pic of the 'reaction vessel' itself, which I've already posted:



The joints of this vessel have been made with Lead (Melting Point 327°C, 620°F) *NOT* solder, using a bog-standard propane torch, and it has already been successfully soak-tested at 250°C (480°F). In use, the normal operating temperature of this assembly is not expected to exceed 200°C (390°F). 
Of course, brazing or silver-soldering is a far better technique to use should you have the necessary equipment.

So here's a shot of the state of build as at this morning:

 

The can is held firmly in position by a pair of s/s wires. A toggle switch has been fitted so that the controller will still act as an electronic thermometer whilst the reaction vessel is cooling (with the heater switched off), post vapourisation. The small shield over the connection block is to prevent accidental contact with the 220V present on those terminals.

To the left of the assembly is the gravity closure already mentioned, together with a simple cover made from squashed copper tube which will prevent any dispensed Oxalic Acid from falling down the delivery tube - thusly:

 

And finally, with the gravity closure in place:



So - all that remains now is to wire the thing up and insert a K-type thermocouple in-between the bottom of the can and the rubber insulating washer below it. I'm sure that'll perform adequately for now, although I'll rig-up something more workman-like for the finished product (assuming that ever happens ...  ).

LJ


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## beekuk (Dec 31, 2008)

little_john said:


> Johno has discovered that injecting OA dust at or near the top of the hive is preferable to dosing from the bottom - so for now I'm sticking with this principle


Also found that the treatment is more effective from the top a few years ago, like your design LJ, only thing is it maybe better with a bend at the bottom of the vertical tube or raise it higher if using direct down through a crown board hole, use sublimox vaporizers here and the heat of the vapor straight from the nozzle is quite hot, hot enough to fry some bees and one could well be the queen if using a center feed hole, maybe your device will be cooler...just my thoughts on it.


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## crofter (May 5, 2011)

That certainly opens up some different aspects. It would be so much easier to administer through the inner cover rather than humped up like a dog on a football using the hole in the bottom rear of the hive. The discharge tube out the bottom would be an easy construction. No handle needed.

Using the plywood bottom would accommodate everything from a feed hole to a bee escape hole or even a small drilled hole if your inner cover had no openings. The flat gravity seals would be positive sealing and easy to create. Silicone sheet is readily available in kitchen section of department stores or made with tube of liquid hi temp silicone.

Cycle time could be reduced if you did not wait till the bowl came entirely back to room temp. I found with the tray heaters that a temperature of approx 180 F. would allow dumping in a fresh charge without any fuming and quickly brought up to vaporization temp. With two such units leapfrogging I think they could be quite efficient.

I am a thinking that I will be using those ideas to make one without temperature controls. I use Sil Phos for joining so will not have to worry about the temperature limitations of the lead base solders.


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## little_john (Aug 4, 2014)

beekuk said:


> [...] raise it higher if using direct down through a crown board hole, use sublimox vaporizers here and the heat of the vapor straight from the nozzle is quite hot, hot enough to fry some bees and one could well be the queen if using a center feed hole, maybe your device will be cooler...just my thoughts on it.


Hi Pete - hope you had a good season.

Very much appreciate your comments about the heat issue - to be honest, that's something I hadn't even considered and I'm not sure why ... maybe just because it's not an issue which features much with the Sublimox(?) - but as you rightly point out, in contrast I could be dosing more-or-less directly above the cluster. Point very much taken.

What I'll do now is to test with a sheet of thin wax lying across the top bars (of an unoccupied hive, of course) and check it for heat damage. I'll then raise the whole assembly with shims of 10mm plywood until that damage disappears. I know that's hardly any guarantee, but right now I can't see another simple method of determining some kind of acceptable temperature. I don't think inserting a thermocouple into the exhaust stream would help much as I'll be looking for a fairly fast peak temperature event.
Then, assuming that cures the problem, the copper fittings could be mounted on top of (say) a 2" wooden stand-off tower - or whatever height is considered necessary.

Many thanks for that, Pete. Always good to get input from others.

LJ


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## little_john (Aug 4, 2014)

crofter said:


> I am a thinking that I will be using those ideas to make one without temperature controls. I use Sil Phos for joining so will not have to worry about the temperature limitations of the lead base solders.


Hi Frank - yes, with that method of joining you could just time the operation a few times, add 15 seconds or so ... and I'm sure that would be good enough. It could even be automated with a $2 timer ex Ebay ! 
LJ


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## robassett (Feb 26, 2018)

Why have a plug on top of the crucible and force the vapor out the bottom? I am thinking of using an inverted glass bowl with weatherstrip around the edges, sealed over the opening in the inner cover. Let the vapor come out the top of the heated crucible (under the inverted bowl) and find its way down through the inner cover. Glass bowl because then I can see when the OA is all vaporized and turn off the heater.

I bought a band heater to try this out, but over a month later when the heater arrived from Thailand, it was only 16 watts, not 300. Couldn't even bring a few cc's of water to boil in 5 minutes.

---Robin


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## johno (Dec 4, 2011)

Lj the only thought I have with treating from the top going straight down is that the vapor jet will be going down and not creating a layer of vapor at the top, one would think if there was a horizontal baffle plate a little below the outlet pipe that it might get the vapor to disperse horizontally in a 360 degree plume. You would need to do tests with a plexiglass top to try to see where the vapor flows.
Johno


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## crofter (May 5, 2011)

johno said:


> Lj the only thought I have with treating from the top going straight down is that the vapor jet will be going down and not creating a layer of vapor at the top, one would think if there was a horizontal baffle plate a little below the outlet pipe that it might get the vapor to disperse horizontally in a 360 degree plume. You would need to do tests with a plexiglass top to try to see where the vapor flows.
> Johno


I had the thought that a way to handle this concern as well as hitting hot on the bees, would be to baffle the bottom of the discharge tube so the vapor would be deflected out horizontally. If the inlet to that tube was open on the inside as in LJ's design, cleaning could be done from there. I have not found build up to be a problem though as long as discharge snout was hot and short.


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## Barhopper (Mar 5, 2015)

That’s thinking outside the box. You need to be sure to have clearance from the discharge to the frames. If the vapor hits directly on a close frame it will scorch it.


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## johno (Dec 4, 2011)

As a means of getting a good coverage of vapor at the top of the hives I am looking at building my migratory tops with a 3/16" slot at the back of the rim I put onto them to get correct bee space and then drilling a 1/4" hole through the back cleat to meet the 3/16" slot so that I can easily treat from the top. Also planning to build some Imrie type of shims to go above my queen excluders in spring. First of all that will give the bees more access to the honey supers and will also mean I can slip a boardin over the excluder and treat with OAV if I feel the need.
Johno


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## little_john (Aug 4, 2014)

Update - today was the first warm day for quite a while: we saw 9-10°C (48/50F) for several hours this afternoon, so I took the opportunity to do a mid-winter VOA treatment - a couple of weeks later than planned (due to British weather !).

Two good points and two not-so-good points from this trial:

Pressing a button (or in my case, flicking a switch) and 'walking away' is nothing short of brilliant - I'm completely sold on this idea. And the weighted gravity closure has also being working flawlessly.

Negatives - the speed of treatment really is desperately slow, although this could always be improved by running multiple units simultaneously. But - there was one completely unforeseen HUGE negative ...

When cracking-off the feeder-hole cover, in some (but not all) colonies bees immediately crowded into that area. Whether this is due to them occupying the space between the Crown Board (inner cover) and frames due to warmth issues, or whether this is a learned response due to my use of overhead jar feeders - where they frequently crowd into that area in anticipation of a feed whenever they sense my presence - couldn't say for sure. But whatever the underlying cause, that's a BIG problem as some of those bees would be getting the full blast, and from close range too. Not good. In practice I was able to somewhat overcome this by placing feeder jars over adjacent holes to entice them away from that hole, and then coming back to dose the hive later - but this was more sodding around which only served to interrupt the work flow.

So, all-in-all an interesting 'first time out' - but I'm beginning to question the viability of this approach. 
LJ


FWIW - this is a shot of a frame top bar afterwards, which is some 18mm (3/4") from the end of the delivery tube.



As far as I can tell without a perspex top, the OA dust appears to spread reasonably well after striking a top bar.


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## DUX4LIFE (Sep 9, 2013)

Has this design gone any further? Tonight I tried to come up with an idea and this is where it is. I used a 1 1/4" copper cap and coupler brazed together. I drilled a hole into the copper cap and inserted a 5/16" ID piece of tubing with 3/4" of it sticking out. I brazed the end shut and drilled about 8 holes 1/16" diameter around the circumference of the tubing for 360 degree dispersion. I wrapped a band heater around the item and plugged it in. The results look good for further testing. I would say the vapor traveled aprox 10" in all directions under pressure. I had complete sublimation with no burning. Also since I didn't have any holes drilled straight down I think it may save a few bees during the treatment. My plan is to make a round cylinder perhaps a 3" piece of black pipe and center this vaporizer in the middle. Maybe attach a handle and treat it kind of like a coffee mug. Operation would be like the other vaporizers using a silicone plug to deliver the acid upon inverting the unit I think I can just open the outer cover and treat through the feeder hole of the inner cover without stirring up the bees. A few puffs of smoke would also clear the immediate area of any bees prior to insertion. I Will play around with the differend depths of the tubing also. I would like it to be just above the top of the frame so as to disperse the vapor in the bee space between the top of the frame and the bottom of the inner cover. It has much less pressure than the units that I made using a single 3/16" output tube.


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## little_john (Aug 4, 2014)

Good to hear of someone else 'stretching the envelope' ! I'd very much like to see a photo (or three) of what you describe - if that's possible - thanks. 



> Has this design gone any further?


Well, not this particular design - but I've since been thinking along parallel lines.

As I see the Varroa situation, I reckon it's going to be around for a very long time yet - and is such an important issue that it warrants a significant hive design alteration (rather than trying to fit VOA applicators into existing equipment). So - what I'm currently thinking in terms of is: to have a modified hive base with sufficient internal height to accommodate the band-heater equivalent of the classic Varrox wand. Such an applicator could consist simply of a band-heater around a copper can, with some kind of insulating pad beneath it - and that's all. Such devices could be made very cheaply: rough costings suggest around $5-6 each, so running (say) 8 at a time would then make this a practical proposition, even if each VOA run should take 10 or even 15 minutes from 'cold to cold'.

There is another potential application of such a device, which I had considered floating out to experienced members here in order to sound-out it's practicability ... and so this is as good an opportunity as any to do this.

I want to say from the outset, that I'm not entirely convinced that heat treatment of Varroa is practicable - that heat treatment itself 'works' is not being doubted - but the very idea of around 3 hours for each treatment renders this (imo) a non-starter, that is, in contrast with existing methods of delivering VOA - even the slowest of those methods.

But - suppose a simple band-heater device such as I've already described was allowed to dose the hive with VOA, and then be left in place in order to heat the brood area of the hive during the subsequent two or three hours ?
A system controlling (say) 8 such band-heaters is very do-able (industrial temperature control being one of my areas of experience) especially when using modern electronic components. Assuming 250W per heater, then a supply of around 2KW (peak) would be required - which should not pose a problem if mains is available - but a 3KW generator would then be required in the field.

Looking at this positively, after such a treatment a hive should be - for all intents and purposes - Varroa-free (or at least as 'Varroa-free' as any hive needs to be, as the prospect of re-infestation will always be present), with both 'phoretic' mites AND mites within cells having been dispatched - BUT - nevertheless, is treating even 8 hives every 3 hours a realistic prospect ? I'm really not sure about this, hence my request for opinions.

The DIY cost of such a system ? Maybe $100-150. I really don't think cost is very much of an issue - it's more about the effective use of a beekeeper's time.
LJ


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## crofter (May 5, 2011)

Dux4life; your idea seems well thought out. I am thinking I want to be able to do top dosing so it is possible when my hives are deep in snow and the present rear bottom board is in accessible. I could use your idea as is without thinking I needed to _personalize_ it! :thumbsup:

LJ; if you want fine and even control of temperature over a considerable area and volume, I think a larger and less intense heat source would be easier to manage than a band heater. That seems to have been an issue in the long duration comb heating mite killers. Not a big spread in temperatures between what is deadly for the mite and what is survivable by the bees and brood.


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## little_john (Aug 4, 2014)

crofter said:


> LJ; if you want fine and even control of temperature over a considerable area and volume, I think a larger and less intense heat source would be easier to manage than a band heater. That seems to have been an issue in the long duration comb heating mite killers. Not a big spread in temperatures between what is deadly for the mite and what is survivable by the bees and brood.


Sure, I don't disagree with your comments. But - I was thinking of working with what's already available.
The 'intensity' as you put it can very easily be dealt with by PWM control to reduce the effective wattage to whatever's required. It would be better to have a larger heater surface area though, I agree. With a concentrated heat source there may be a case to install a small fan to improve circulation - such details can be established during testing. FWIW, the best method of control for this kind of application would be Cascade Control.

But - 8 hives in 3 hours - is this idea even worth developing ?
LJ


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## crofter (May 5, 2011)

Yes you can use a fan to help evenly spread the heat. I was not dissing the wattage of the band heater though it is likely more than enough to overcome heat loss. You can control wattage delivered as you mention but even heating throughout is greatly complicated by a small area source. If you try to do it with fans then you create a potential problem with dessication. I have seen some overheated colonies and the bees fan like heroes and would dearly like to get out and haul some water for evaporative cooling. You and they will be working at cross purposes. 

I am not big on anthropmorphising but I think that way of killing mites borders on cruelty to the bees. OAV cant be a picnic either! Lol! I dont like the exposure time requirements either for the whole hive heating method.


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## little_john (Aug 4, 2014)

Hi Frank - I'm not completely 'sold' on the idea, either - it was just reading about the technique and observing that the heater being used was more-or-less the same kind of wattage *and *that the use of VOA was an additional requirement for an effective 'mite kill' - that I started thinking about putting the two events together, by using the same basic kit.

I agree with you totally about the trauma aspect - especially when compared with my own bees' complete non-reaction to VOA. Always good to get the views of others.
LJ


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## little_john (Aug 4, 2014)

Last week I completed yet another sequence of treatments using 'the prototype' which was shown earlier in this thread - and personally I continue to be sold on this particular variation of the band-heater Vapouriser: open the feed hole, small puff of smoke to keep any inquisitive girls away, place the kit on top, load-up the OA, flick a switch and walk away ...

There's no need for any PPE when using this method, and while the can is either heating-up or cooling down, the roof and feeder shell of the previously treated hive can be replaced, and those of the next hive can be removed in readiness. 

I've found that the vessel can be recharged with OA at 130 deg C (indicated) without any fumes being generated, and that vapourisation is completed by 170 deg C (indicated), so a complete cool-down isn't necessary - which speeds things up considerably.

However, sometimes a small amount of waiting time does occur - which could very easily be eliminated by the use of two such vapourisers - indeed, they can be so cheap to make that using 2, 3 or even 4 at the same time becomes feasible.

Anyway - the reason for this post is to share the modification I intend making during the coming winter period - which is to install an 'extended delivery tube', blanked-off at it's end, and with 4x 1.0mm (or thereabouts) holes drilled into it such that jets of VOA will be delivered into the beespace above the frame top-bars thusly:



Although I figured this out independently, I've just realised that DUX4LIFE had already suggested this modification - or something very close to it. I think his idea of modelling the vapouriser on the shape of a 'Coffee Mug' is inspired, and of course there's no need for a temperature controller to be used as the temperature isn't being maintained - the principle here being very similar to that of the Varrox, and so some form of thermostat, or even a timer should be adequate.

In practice the gravity closure has worked perfectly, is far cheaper to make than a silicone bung is to purchase, and I anticipate will have a long life-expectancy due to the lower temperatures involved.

One negative is that this variation is slower than Johno's method - principally because of the need to expose the Crown Board (Inner Cover) rather than poke a nozzle through a hole in the back of each hive - and I'm finding it is this which limits the speed of use rather than the heating-up/cooling-down times. However, positive aspects are that it's a much cheaper build (at around $10, DIY) than an inverting band-heater unit, and also there's zero chance of encountering the OA aerosol due to the operator separation distance. (Not that I've ever seriously entertained such concerns when using the classic inverting method)

So there you go - this might be a method worth considering for anyone with (say) up to 20 hives or so. I do have more than that number of colonies myself, but I intend working with 2 or 3 units. 
LJ


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## mgolden (Oct 26, 2011)

Makes the exhaust tube much shorter, so should keep the interior of the tube cleaner from blockage.

With a migratory top, one would only need to remove the pipe end cap and place unit over hole.

Still 1 1/4 copper and an aluminum plug in bottom???

250W, 1 1/4 inch inside diameter band heater, 110V band heater for North America???

Silicone cone on under side may be nice to center top cap/plug. 

Similar action as Varrox and reduces need for mask.


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## little_john (Aug 4, 2014)

There's flexibility re: whatever materials are readily available in your own country - in Britain one solution for making the 'can' would be to use a 35mm copper end-feed end-cap, and attach that to a 35mm end-feed coupler with an inch or so of 35mm copper tubing. But as it happens I'm using some 36mm brass tubing which was a 'once-upon-a-time' Victorian greenhouse sprayer (bicycle pump type), and have enough tube to make 3 units. The current band heater is 35x45mm 150W and works very well, and so I think I'll be sticking with that size - although it is tempting to use 28mm copper fittings as this size is far more common here (and significantly cheaper), with a band heater to match. Most 30mm dia. band heaters tend to be 120W.

There's basically only two components which cost any money - the can and the band-heater - the cost of everything else is only pennies.
LJ


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## little_john (Aug 4, 2014)

Bit of an update ...

I never did get around to modifying my top delivery (non-inverting) Band-Heater Vapouriser, as I've pretty-much decided to make half-a-dozen Varrox-style applicators using Band-Heaters instead, so that multiple hives can be dosed at the same time - from below.

But - I do have several hives where only a top application is practicable, so during this season I've been playing with this set-up:










As I'm sure is obvious, all I've done is to modify an old wooden Crown Board (inner cover) by cutting a large hole in it towards one side, over which I've glued an open box. 
The Vapouriser then sits on top of that, with it's outlet some three inches away from the frame top bars. This set-up works well, but is excruciatingly slow ... Still, it'll only need to be used on a handful of hives

Another thing to be reported is that my idea of using a (weighted) gravity closure rather than a bung has been working extremely well - that is, until last week when it started leaking. The reason was a build-up of Oxalic Acid on the surface of the rubber, which is almost impossible to remove without causing damage to the surface. So - I had to reverse the silicone rubber disk in order to continue work. However, it does make for an extremely cheap option, much cheaper than MoCap bungs, and so I'll now make a few spare disks for replacement (say) every other season.
LJ


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## crofter (May 5, 2011)

LJ;

What set point temperature are you using on the controller? I think the inverting type are using ~204 C. but thinking that would be hard on the silicone pad the vessel sits on.


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## little_john (Aug 4, 2014)

Hi Frank,
according to the MoCap people, their silicone rubber bungs are good for 300 deg C. But - I think that claim refers to destruction of the material by heat alone in air, and doesn't take into account the aggressive nature of a hot organic acid. I believe the silicone rubber sheet I'm using is the same material - it certainly looks the same, feels the same, and reacts to hot OA in exactly the same way (i.e. forming a grey-coloured crust on it's surface) .

I've set the PID controller on the experimental rig to 170 deg C., but I frequently see temperatures as high as 190, as it merrily overshoots set-point. Thought I'd tuned the controller but it looks like I forgot. 
LJ

Sorry Frank - I've just realised what you wrote . Yes, I'll check on the pad the can sits on tomorrow - and see what that looks like.


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## Biermann (May 31, 2015)

Well - LJ & others,

Anything can be improved on and will be.

Lets look at some facts

The inverting Vaporizers come from the disappointing results of the pan vaporizers, I call them 'bee-fryers', 'hive burners' or worth, 'pieces-of-sh...'. They also get nothing done in a 1 or 2 hour time span.

Brings the operational beauty of the inverting VAP's. How can one treat a double deep, without opening, in 15 or 20 seconds any other way? I have not found one, other then the industrial units for $2-2,800.

Frank, if you still need to vaporize when it is lousy cold and the snow is flying, you missed the target, sorry to say. Because you can not penetrate inside the clustered bee-ball anymore. treating time for me is late October-early November in the evening when everyone is home and we have still around 6-8°C outside. For you that could be second 1/2 of October, 7x, 4 days apart. I have no mites anymore and do this treatment exclusively in fall and in spring, nothing else.

For the band heater temperature, I set my units to 204°C, (400°F). I ship with the 'learning' PID enabled and I feel a temperature around 185-190°C does the best job and keeps the silicon plugs much longer. I feel that the OA vapor may damage the plugs more then the heat, but I am not a silicon scientist.

I should encourage the user to try lowering the set temperature in my manuals, but I already see all the email, texts and phone calls 'this darn thing is not working'. So, 'Product-maker-safety' first and 204°C (400°F).

My treating spot is in the back of my hives, 2' of ground level and I have back problems for a long time, this has not increased my pain. 

Again, anything can be improved on, please do.

JoergK.


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## crofter (May 5, 2011)

Biermann said:


> Well - LJ & others,
> 
> Anything can be improved on and will be.
> 
> ...


I am quite happy with your unit. I did a bit of damage to one of the plugs by leaving it in with heat on for an extended period of time. Now I pop the plug out as soon as I hear the relay click off, and the caps seem to appear headed for many, many cycles. I have to go by sound since I am red color blind and cant read the screen unless inside, out of the daylight.

I have a very easy time winning the battle with Mrs. Varroa!


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## little_john (Aug 4, 2014)

*Biermann* - first of all - *this thread is about a non-inverting design.* I did not start this thread so that someone else could use it to promote their own existing but dissimilar product.

One problem with inverting Band-Heater designs is that the operator needs to physically hold the device for the duration of the 'burn' - no matter how short that happens to be.

With a non-inverting design - which is much slower - the operator is free to move around, and more importantly can operate the device from a distance - much safer.

Existing methodologies are all based on the use of a single (and relatively expensive) applicator - my current plan is to make half-a-dozen simple (and very cheap - $5-7) vapourisers which can be used simultaneously. So that, even with a treatment time of 10 minutes (say) - when divided by 6, that becomes comparable with other existing methods. 

For a low-profile device, a cartridge heater could be used - but I'm sticking to the band-heaters I already have. There will be no need for bungs or any other form of closure.

The number of units can be varied according to the number of hives to be treated, and promises to be an extremely low-cost system.
LJ


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## johno (Dec 4, 2011)

LJ, that the operator has to physically hold the device for the duration of the treatment on the Easy Vap is not so, when the unit is inverted with the nozzle inserted it is left to hang on the hive enabling the keeper to prepare the next hive and returns to remove the vaporizer when it has reached over 400F when all the OA has been sublimated.


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## Biermann (May 31, 2015)

LJ - my apology if it looked like I am advertising my unit. It was not the intention and frankly, it is not needed. What we need is more guys building them.

Anyhow, one can only judge what you are trying by looking at where your idea came from and it did not come from the gasoline engine, but the inverted VAP, so why not compare and see the good and bad.

Again, I am sorry if you feel I hijacked your thread.

How do you indent to make your unit cheap?

Buying PID's now is CAD30-35, a good Mica band heater is CAD19 to 25 odds & ends CAD10, so you are already at CAD54.00 (31 Quid) if you build more then 1 or 2 from eBay luck material. You have no time in it, yet, and, is it really safer, I don't know.

Your wooden box may serve your purpose, but would it serve a customer that has to pay for it?

Again & again, I applaud what you build, but let us know if you don't want any meaningful discussion and we will not make a peep.

Cheers, JoergK.


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## crofter (May 5, 2011)

What I would like to see for simplification of most any of the devices is by way of a device to make a measured dose of OA into a solid tablet or vaporizing capsule. This could be tossed in without the need for the inverting. Perhaps could dispense from a tubular or cylindrical hopper. A time delay function could accommodate being able to vaporize from a distance if you are averse to wearing a mask.


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## johno (Dec 4, 2011)

Frank I am of the opinion that a tablet form of OA will take longer to sublimate than just the powder form as the powder will provide a greater surface area than a tablet. LJ I am also not clear what your objectives are with a non inverting vaporizer? Will you still temperature control? You will also need to use a migratory hive top. Now if you could get the wattage right so that the device does not exceed say500F or 260C and also mould a base around the bottom of gypsum to which you could attach or mould in a small handle there could be some advantage. Will plaster of Paris handle that temperature.
Johno


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## little_john (Aug 4, 2014)

*Frank* - feedback re: the silicone rubber washer at the base of the can. I checked it yesterday after the last multi-dose of this season, and it's perfect - in the same condition as when I first installed it. So it would appear that this rubber can handle temperatures around 200 deg C very comfortably (it's spec is 300) - it's the hot OA which is damaging it's surface.




> LJ I am also not clear what your objectives are with a non inverting vaporizer? Will you still temperature control?


*Johno* - Hi - objectives ? Well, these were never fixed - it started with an experiment to see whether a top application via Crown Board (inner cover) feed holes was feasible. The reason for this approach is that I have a pot-pourri of hives here - long hives, standard verticals, Warre-sized verticals - and now horizontals, as well as various single and multiple-nuc boxes. Dosing a variety of boxes from the top via existing holes seemed a simple solution.

I had planned to modify the delivery tube to give 'sideways jets', but life has been very demanding this year and so I never did get around to doing that. But - August arrived and I needed to multi-dose. So - I cobbled together some kit which lifted the vapouriser some 3 inches clear of the top bars, and which has worked well - much better than before. Pity it's so desperately slow to treat like this. But, as an experiment it was well-worth doing - if only to realise it's shortcomings.

My intention now is to retain this temporary kit 'as is' - to use on any hive which has not yet been modified to accept the 'Band-Heater Varrox'.

I've decided that a 'Band-Heater Varrox' is the way I want to go. These require a custom base for each hive which needless to say won't appeal to others, but I've already built a prototype with a vented floor and the removable slatted rack which is necessary to provide sufficient height.

The plan is to run several of these devices simultaneously on a Master-Slave principle, with only the master unit having a temperature sensor. This sensor could be as simple as a thermal switch (couple of dollars ex Ebay) disabling a locking-relay, although I'll probably use whatever I already have. There's no need for any temperature control of course, any reliable form of thermostat will do the job. No need for any form of closure either - just a can with a band-heater around it, with some means of mounting it onto a heat-proof carrier. I already have a couple made ready to test.

What's the overall objective ? Price. Each unit will only cost the price of a Band-Heater, and a few pennies for the can and other sundries. I estimate around $5-7 for each Slave unit, the Master maybe $10. Added to that of course is the cost of a hive base if you buy, not much of an expense if you make your own woodenware.

Of course. the requirement for a new base could be eliminated if cartridge heaters were used instead of band heaters to produce a lower profile device with a similar height to that of the Varrox - but I already have the band heaters ... 

Varrox-type systems are slow - but if multiple units are operated simultaneously ... 
'best
LJ


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## little_john (Aug 4, 2014)

crofter said:


> What I would like to see for simplification of most any of the devices is by way of a device to make a measured dose of OA into a solid tablet or vaporizing capsule. This could be tossed in without the need for the inverting. Perhaps could dispense from a tubular or cylindrical hopper. A time delay function could accommodate being able to vaporize from a distance if you are averse to wearing a mask.


The Varomor achieves this by the operation of a trigger-operated pump which injects an OA solution onto a pre-heated element. I suppose it would be possible to adapt this principle to inject OA paste into a vapouriser's can - but the problems here would be two-fold: firstly, there's the water content of the paste which then needs to be evaporated, and secondly, a trigger operation still requires the operator to be 'up close and personal' with the equipment. It's also an engineering solution which would cost money to implement.

I know my intended solution (previous post) may seem somewhat wacky to some, but if a person was setting-up (say) five hives at the same time, inserting the vapourisers at the bottom and from behind, then the required dose could be spooned-in with sufficient accuracy, the hives then closed-up, with the operator pressing a button before walking away - returning in (say) ten to fifteen minutes before repeating the same operation on other hives.

My own view is that we need to get away from a 'one-method suits all' approach to Varroa treatment. For those with serious numbers of hives, then an Inverting Band-Heater Vapouriser is clearly a good choice - no contest at all - but if you remember a thread a while back regarding the ideal number of hives for the hobbyist, the figure of ten appeared to be desirable. And a lot of amateur beekeepers have far fewer than ten hives. Speed of application for them is of secondary concern, I would have thought.

Cost and safety would probably rank quite highly - maybe we should hold a poll and ask ?
'best
LJ


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## viesest (Jul 13, 2016)

little_john said:


> My own view is that we need to get away from a 'one-method suits all' approach to Varroa treatment.


On the other side, principle of inserting capsule (as in ProVap EZ) can be implemented in other types of vaporizers. For Varrox 2.0 the capsule would look more like measuring spoon.


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## little_john (Aug 4, 2014)

viesest said:


> On the other side, principle of inserting capsule (as in ProVap EZ) can be implemented in other types of vaporizers. For Varrox 2.0 the capsule would look more like measuring spoon.


Thanks for the ref. I've just done a Google for ProVap EZ. $735 - serious money.
The mechanism is certainly ingenious - but the capsule will need to cool down before it could be re-used, so it's not quite as fast as would first appear. Also - DIY-ing that method would require some significant engineering, and so perhaps is not really suitable for the home DIY-er ? 

In contrast, the Varrox 'principle' (if you can call it that) is simplicity itself. It may be slow, but for some people that isn't an issue.
'best
LJ


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## viesest (Jul 13, 2016)

little_john said:


> but the capsule will need to cool down before it could be re-used


 Capsule is not expensive; I have 5 copper caps for that purpose.



> In contrast, the Varrox 'principle' (if you can call it that) is simplicity itself. It may be slow, but for some people that isn't an issue.


Varrox (wand type) with capsule is not slow, in my case it is 2+ minutes per hive.
If you didn't pay attention about my vaporizer here is picture of it again.







It resembles most of requirements in your posts. It is gas powered and battery powered would be even more simple and safe.


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## little_john (Aug 4, 2014)

viesest said:


> Varrox (wand type) with capsule is not slow, in my case it is 2+ minutes per hive.
> If you didn't pay attention about my vaporizer here is picture of it again.
> [...]
> It resembles most of requirements in your posts. It is gas powered and battery powered would be even more simple and safe.


I think we're talking different languages ....

Whether people like it or not the Varrox(*tm*) is the original vapouriser and has become a standard by which all other vapourisers are judged. So - when someone mentions the term 'Varrox' they are referring to a specific piece of equipment.

Thus, I was being specific when I said that the Varrox was slow (relative to the speed of inverting Band-Heater Vapourisers).

You then say that a Varrox *type with capsule *is not slow. But of course the Varrox(*tm*) doesn't have a capsule, neither is it gas-powered.

Your device appears to require PPE as the operator is required to stand close to the equipment during operation, as does the ProVap EZ. The manufacturers of that device are insistent that PPE must be worn - and in addition wear heat-resistant gauntlets ! 

What I am suggesting is a device (or rather devices) which can be operated remotely, and during the operation of which - for safety - the beekeeper need not remain in close proximity to the equipment.

Incidently, there is a slight problem with the ProVap EZ design. The manufacturers state: "*The capsule when dipped into the OA picks up two grams… just the right amount for a double brood box hive.*" So what happens if you want to dose a single brood box hive, or a nuc, or any other form of hive which isn't a double brood box ?

A design which can only deliver a fixed dose must be considered as being flawed.
LJ


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## viesest (Jul 13, 2016)

little_john said:


> I think we're talking different languages ....


No, we are not.


> What I am suggesting is a device (or rather devices) which can be operated remotely, and during the operation of which - for safety - the beekeeper need not remain in close proximity to the equipment.


Well, understood, that's why I was suggesting that you can consider to implement principle of capsule.
PPE requirement for ProVap EZ is logical, yet wand type vaporizer can be left in drawer after capsule is inserted into it. (btw. I have respirator... still in its original package)


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## crofter (May 5, 2011)

Kicking this thread to the top again. Some people have not seen this thread or considered the advantages of top introduction of the OAV. It has some advantages especially in colder weather when the bees will be at the top anyways. Some people have also found that with double or triple deeps, with bottom injection the dust cloud does not go up into the upper frames well without opening the top some.

Construction of the vaporizer can be pretty simple and as Little_john does it, does not require a respirator. Might be an option with someone with a handful of hives who is not enthralled with sliding the wand type in under the frames. Similarly to a current thread, I think an existing wand type could easily be converted to bottom discharge.

Below is an old one I played with. Its problem is it was a bit too tall and cutting it down would make the bowl capacity to small. A down pipe and a cap would convert it.

Lots of diffrent ways to skin a cat!


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## little_john (Aug 4, 2014)

Hi Frank
During excursions around the Internet, I came across the following beehive - a Ukrainian Hive with a novel feature:










and a close-up










As I'm sure you can see, the yellow hive shows a removable panel at the base of the end wall furthest from the entrance - which is provided for cleaning the bottom-board with an L-shaped scraper, but which of course would also provide access for applying VOA from below.

So - that's the plan from now on - to provide all my new extra-deep-frame hive builds with this feature.
'best,
LJ


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## crofter (May 5, 2011)

Yes it would be nice to have an easy clean out that could serve as an opening to run in a swarm or slide in a screened sticky board etc. I have not decided yet what the bottom will be. So far the walls pieces are cut to length and through holes drilled for edge joining. As is it will have approx 21 1/2" height if I dont trim. Lots of room for the 19" langs to stand on end. Probably what I will borrow to run in it to populate with bees. 

Have to wait for warmer weather for glueing. Could haul it in beside the wood stove in my mud room and assemble it. So far just doing some frames for it inside.


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