Is this home made Heating Mantle any good?

[Justincase]

I have been looking for some heating mantles to run my round bottomed flask's
I am a bit fed up with sand baths
A friend suggested this to me , https://www.youtube.com/watch?v=QKFC0ke_DOU
Not sure it looks to safe using exposed electrics run heating off a variable power source.
Any opinion's??

 

[necromancer]

i was going to build some of those but by using these:

zone heater

they have a heating coil already wrapped around a ceramic cone, i get them free all the time
i find people drop them & the connection for the safety switch gets stuck, just pop it back in place and its good as new

they have temperature dials (#1: low, med, hi & some have 1 to 10 settings)

edited: spelling

 

[Shark]

That is pretty ingenious for heating a flask. The plaster ones I would do a bit differently by adding a plug to the wire so it could be plugged directly into a normal plugin socket and eliminate the exposed wires. The wiring would need to be heat rated I assume. I put a light switch together in a box with a light dimmer a while back to control the heat on crockpots and soldering irons and would use it for the power source. It would be better with temperature markings though. I haven't got that far with it yet except on the crockpots. I also use the soldering iron, with a modified tip for welding plastic. The old style flat nichrome wire used for 110 volt electric heaters can still be bought from some wiring supply shops in the U.S. as well. Here in town, 20 feet costs $12. I am glad I don't have any sheetrock plaster on hand right now, I would have to try that and I have gold to work on tomorrow, it would be a tough choice, almost :mrgreen:

 

[g_axelsson]

The biggest threat from the exposed wires should be if you power it from an unisolated power source. For example from a variac where you have a 50% chance to plug it in and have the full voltage out even when the output voltage is turned down to a low level.
To understand why you need to know how a variac is constructed. See Autotransformer on Wikipedia.
The plaster could also become conductive if you drop salt solutions on it and you could get a shock even if you protect the wires going out of it.
The best solution is to make several shorter windings in parallel and power it from a variable DC supply.

Göran

 

[Shark]

Thanks to your previous post I went and looked at the unit I have on hand and was happy to find that it's out put was DC. It has been in storage for several years because I had thought it was an AC in/AC out. I found the current manual for my unit and will have to do more study before doing anything with it. It is AC 110/240 input, 0-90 volt DC out but seems limited to 15 amp, not sure about the amps yet though, need to take more time to better read through the manual yet. Since I am no electrician, it takes me a while to figure these things out, luckily I know two guys that do know what they are doing.

 

[Barren Realms 007]

Thanks to your previous post I went and looked at the unit I have on hand and was happy to find that it's out put was DC. It has been in storage for several years because I had thought it was an AC in/AC out. I found the current manual for my unit and will have to do more study before doing anything with it. It is AC 110/240 input, 0-90 volt DC out but seems limited to 15 amp, not sure about the amps yet though, need to take more time to better read through the manual yet. Since I am no electrician, it takes me a while to figure these things out, luckily I know two guys that do know what they are doing.

Devide your watts by your voltage and it will give you your AMP's.

1500W / 110v = 13.6 AMP's

 

[Shark]

I read through the manual again and it is well over my head. I do know what it was used for but the motors I have for it are shot. It was used to run conveyor belts to various departments in a large plant. It controlled the speed of the belts, and has a jog/run switch separately to index the belts into place to drop boxes of goods in the correct locations. I don't think I can use it for what I had hoped, but will have someone look it over and see. Here is a link to the manuel for those interested in such things.

http://www.camcoindex.com/ServiceManuals/CAMCO_Varipak-DC-Control_Manual_0083.pdf

 

[Barren Realms 007]

I read through the manual again and it is well over my head. I do know what it was used for but the motors I have for it are shot. It was used to run conveyor belts to various departments in a large plant. It controlled the speed of the belts, and has a jog/run switch separately to index the belts into place to drop boxes of goods in the correct locations. I don't think I can use it for what I had hoped, but will have someone look it over and see. Here is a link to the manuel for those interested in such things.

http://www.camcoindex.com/ServiceManuals/CAMCO_Varipak-DC-Control_Manual_0083.pdf

Sounds like you have a motor control station and not a variac. Different bucket of worms.

 

[g_axelsson]

First of all I would like to add a warning, I only skimmed the manual but I couldn't find any reference to this being "isolated" between AC and DC sides, it could mean that the DC side could have a connection to the AC side and have a large potential. But my experience tells me that most AC/DC aggregates are isolated. This can be checked with a multimeter easily.
Some of the connections is NOT isolated, for example the terminals for the potentiometer that controls speed (voltage). If you are uncertain on how to connect it I would recommend you let someone with knowledge to do it instead.

Actually the controller could deliver a quite high DC voltage, high enough to be dangerous in it self.

With that said, it could actually work as a heater controller, but you have to match the resistance of the heating coil to the power supply to get the best effect out of it.

Göran

 

[Barren Realms 007]

First of all I would like to add a warning, I only skimmed the manual but I couldn't find any reference to this being "isolated" between AC and DC sides, it could mean that the DC side could have a connection to the AC side and have a large potential. But my experience tells me that most AC/DC aggregates are isolated. This can be checked with a multimeter easily.
Some of the connections is NOT isolated, for example the terminals for the potentiometer that controls speed (voltage). If you are uncertain on how to connect it I would recommend you let someone with knowledge to do it instead.

Actually the controller could deliver a quite high DC voltage, high enough to be dangerous in it self.

With that said, it could actually work as a heater controller, but you have to match the resistance of the heating coil to the power supply to get the best effect out of it.

Göran

The convergence of AC to DC is done through seperate coils and they are not directly connected.

 

[Anonymous]

Justin. I've got a good UK supplier who has "proper" mantles and power supplies at very very good money. Drop me a line or give me a call and I'll pass the details on.

Jon

 

[necromancer]

here is a photo of the assembly from the zone heater i was talking about.



the safety shut off switch for the zone heater is in case it falls over, the heater will automatically shut off.

if i use this the switch will be bypassed.