The band heaters that I used are still available on ebay from about $3 each, they are 110v x 300w and are 25mm x 30mm I have a couple of these without temp control and they work just fine. Used 1" copper pipe and a 1" pipe cap and made the loading caps from ply and 1" OD aluminum tube. The directions are all in this thread but the outlet has changed to 3/16" copper tube.
Ok one more question that maybe I am not seeing through the forum.. on your assembly how is the bolt attached to the 1" cap ... I ordered two bands from amazon. The video was very helpful but would have loved to see it up close 360 to get the full picture...thanks this is very helpfyl
A #10 goes through a 3/16" clearance hole in the bottom of the 1" pipe cap and is fastened with 2 nuts to give some clearance off the aluminum bar and then a 3rd nut holds the whole thing onto the bar. The 3/16" hole for the outlet is made in the middle of the 1" pipe and so that it is just above the band heater clamping screw so that it will remain hot and not plug up. You will also have to replace the band heater clamping screw with a #8 or #10 screw with a nut on the outside of the clamp, Once the band heater is opened up the old screw will no longer fit. Do not make the 3/16" outlet pipe more than 2" long. I think the 1" pipe is 2 1/2" to 2 3/4" long.
I'm starting to put together my own vaporizer. I just received the band heaters. Have you guys made any changes to your designs recently I should incorporate into my device? I don't have aluminum tubing so will have to find something else to use for the cap. I was thinking another 1" copper cap.
to make up 2 caps you can use 2 3/4" end caps screwed to a piece of what ever you want to use, then use some hi temp RTV silicone around the bottom of the 3/4" cap to make a push on seal. If you try to use a 1" cap once the band heater heats up the vaporizer the expansion will prevent the top 1" cap from fitting. I am still working on trying to make a perfect cap. But as the vaporizer is you need to preheat for 4 1/2 minutes then you can easily do a hive a minute. I am also looking at using 2 band heaters on the temp controlled unit I have to see if I can get the time down to less than 30 seconds a hive
Joe that looks very interesting and if it will stand the heat for a reasonable amount of time it could be an answer to the cap problem. Will the plug seal on its own or will the pressure push it out? Have you already used one and how did it stand up. I would like to try them.
it seals good until my discharge tube clogs , then it will "pop" and shoot a few feet into the air. The hole in the center is a little small, I had to open it up with a die grinder so I could get 2 grams into it. The heat doesn't seem to be a problem (manufacture says good to 600). they are wearing a little on the edges so I think they will be used up after a season. 5 of them with shipping was around $13. I am using a 30MM band clamp and 3/4 copper cap, and union. I put a 3/4-1/2 reducer in the bottom as a heat sink.
Those rubber caps work very well although it is difficult to open up the hole to take more OA. If you find an easy way to do this please let us know. When using the rubber cap it helps to bell the top of the 1" pipe which I do after welding the thing together and then tapping a tapered plug into the pipe until you have a small turn in the top. This allows the rubber cap to seat nicely into the pipe. If you are using any other cap that you need to hold down don't accidently turn the device upside down again as you can get that hot liquid OA come running out of there and the results are not pleasant for your fingers. The next step is to have 2 band heaters on the temp controlled unit to see if I can get treatments down to below 30 seconds continuously
Like I said I use a die grinder with a carbide bit, it takes a few mins and you have to clean the bit a few times but it will open it up. Now you got me thinking, 2 bands..... Do you know how much power the cheap ebay bands draw?
Thanks Joe, The band heaters draw about 1 amp at 120V so 2 would be twice that or around 20 amps through a 12v inverter so I would say a little over 300 watts. I think this would require temperature control. I tried grinding those rubber caps with a small stone in a dremel, enlarged the hole a little but it took forever, what type of bit did you use.
I used a Carbide burr in a cheap (harbor freight) air powered die grinder. looks like this https://www.amazon.com/Carbide-KangT...e+grinder+bits
I am using a TA4-RNR, and a 300 watt inverter....... Now I know what I am working on this weekend. LOL
With one heater, it takes about 90 seconds to do a hive, I would like to shorten that up a little.
Johno I have been following your thread for some time ,it has inspired me to build my own vaporizers on your design thank you for that buy the way.I built two like yourself one with pid controller one not . I made my plugs just like yours except I put a thin coating of black RTV on under side of the cap to help seat and heat proof. On testing them I found as you the pid controller had to be turned up to 500 degrees to sublime the OA and took 45 to 50 seconds to totally finish . The none pid controlled one did about the same.The temperature as checked with cheap Harbor Freight tool showed 500 degrees. They tested good on empty box and glass top ,time after time. I have yet to gas the bees with these units. My question to you is do they work on killing mites and do they turn the OA to formic acid and co2. Pete
Hi Pete, I have been treating at least 50 colonies with the simple uncontrolled device and have been getting good mite drops after treatments. I am still playing with the design to try to get the treatment time down to less than a minute per hive and find that this is not possible with just 1 band heater so am busy building one that will have 2 band heaters and is temp controlled. The device with a single heater is slowed down as the sublimation and boiling off of the water held by the OA requires more energy than the band heater can produce so there has to be a lapse of about 30 seconds before the system can be re loaded to sublimate again. As far as the degradation of the OA to formic and Co2 if there is any from the single heater device I have not been able to sense it by smell through a paper particle mask, however if you were to sublimate a test sample on a still morning and let the plume rise towards the sun you would be able to see the fine OA crystals glittering in the sun. I have found that 2grames of OA will sublimate in less than 30 seconds when the device has been pre heated for 4 1/2 minutes so would like to be able to continue to treat at such short intervals and the reason for 2 band heaters.
Thanks for your reply Johno I'm excited to use mine this summer last year I was using a DIY pipe heated with my propane torch ,it worked well but was troublesome.My hives did good through the winter but I need a better way to treat. I've been following your direction on two band heaters .I would think it would get to hot keep us informed of your progress ,its inspiring for us tinkerers and DIY kind of beeks . Pete
Joe I ground out the inside of 3 plugs and used them when I treated 7 hives in one of my outyards this morning, the top of the vaporizer I used was slightly belled at the top and the silicone plugs closed off completely allowing me to leave the vaporizer hanging in the treatment hole while I prepared the charge and shut off the entrance to the next hive. The only hiccup I have is that the hole is still a little small and takes a little time to fill with OA, So I intend to grind away some more and try to make the cavity larger. This also allows me to move away from the vapor so I might get away from using a mask as near 90 temps and high humidity do not make wearing a mask much fun.
So i a revisiting this project. I built one and it works well. I am looking to build one with temperature control. I have looked through this thread and my previous questions... I know i have asked about this, but not looking for some more details on what and how.
I and looking at PIDs and thermocouples but not sure how they are attached to the setup to control and monitor the temperature. even if someone has pictures of how this is setup would be great. I am also looking for a better cap. any help would be great
King Arthur,If you have a temp controller there is a drawing on the side that gives you the connections, The info that comes with the controller tells you what types you can use. I searched amazon for type K thermocouples, the types used on volt meters that has only the twisted wire exposed so that that bit of exposed thermocouple can be bolted between the bottom of the copper and a stainless steel washer. The best tops I have found so far are the high temp silicone plugs in post 216. I used a dremel and a small grindstone to open up the hole in the cap to make it big enough to take at least 2 grams of OA. I have just completed a vaporizer, temp controlled with 2 band heaters. I find I have to set the temp up at 550F to be able to get a 30 cycle of OA. Once the OA hits the bottom of the vaporizer the temp drops down to the 330F mark and then slowly climbs up towards the 450F mark and by the time you have the next shot ready to go it is above the 500 F mark. This goes to show that 2 band heaters still do not supply enough energy to overcome the latent heat required to sublimate the OA Quickly, although it has speeded up the process to close to 30 seconds.