ManyInterests
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Replacing the inner sleeve on a heating mantle
A while ago I had a drain opener spill on part of my mantle. Long story short, it now only delivers 50% heating power. While I did order a 2 liter
mantle as an upgrade. I did want to repair my 1 liter mantle. I ordered a replacement inner sleeve (which arrived today) and other replacement parts.
I replaced the thermometer probe and the new one works great. But I am not sure how to remove and reinstall and rewire the new sleeve.
does anyone have a list of instructions for that? A video is preferable. I have a 100W soldering iron and plenty of solder.
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ManyInterests
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Here is a picture of the replacement sleeve I got.
 
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draculic acid69
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Maybe a picture of the mantle will help ppl respond.
I've got experience with replacing the electronics
and motors in my mantles but I've never had to replace a sleeve
or even taken the upper half of a mantle off. Maybe I can be of help
Pictures Of your mantle will be a start
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draculic acid69
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Also are you sure the damage is confined to the sleeve and not any of the electronics?
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ManyInterests
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I am pretty sure. Everything else works correctly except that the max-heating is limited. I know it is because when trying to boil sulfuric acid it
only reaches a point where I see wisps of white fumes and it never reaches the rolling boil that it reached previously. It does everything else well
enough though. Stirring is good, and all else is good.
I opened the bottom and none of the wiring is bad. I did take a resistance reading with a multimeter and some told me that it is half what it should
be for a 350W mantle.
I posted two pictures of my mantle, and I will post the seller's page where. They used to sell it on Amazon but have since ceased, they only sell it
on aliexpress now.
shorturl.at/kl036
 
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highpower48
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Should just be a couple of screws holding on the top. There are only two wires on the replacement t sleeve. Just one piece of continus nicrocrome wire
weaved through the sleeve. Hot goes to one, neutral to other end. If the wire is broken it will not heat at all. Kind of sounds like electronics.
[Edited on 11-7-2022 by highpower48]
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ManyInterests
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The screws at the bottom will not liberate the inner sleeve. If I remove it, I can see all the insulation, but and the wires going from the
electronics to the sleeve are short and look fragile. I don't see where I can liberate the sleeve from it's place. I think I might need to contact the
manufacturer.
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Mateo_swe
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First remove the outer top cover, i see screws on the side but sometimes they have used some glue too.
With the outer cover removed it should be more easy to see how the inner sleeve is connected.
You cant solder the wires as the nicrome wire will become hot enough to melt the solder when the mantle is running.
It should be connected with screws on a terminal or crimped, you see how its done on the original sleeve.
The connection must can handle full mantle temperature.
You might be able to wash the original sleeve once it removed, it can be the residue from the liquid that short circuit parts of the original sleeve.
It shouldnt be very hard to figure out how to remove cover and replace the sleeve but they might have used glue.
If you cant get it done, take more pics with cover removed and we try help.
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draculic acid69
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First step would be turn it over so it's upside down (sleeve facing the ground) and then unscrew the base plate which should give access to the
electronics and the connection where the sleeve wire are screwed into a ceramic block with wires that lead to the circuit board. Undo these (the
sleeve connections) then try taking the top half of the mantle off as suggested above by Mateo swe. This should release the sleeve.
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Sulaiman
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IF the wires from the heating element go to a ceramic block screw connector then you are in luck.
Changing the heating element should be straightforward.
Other termination methods may need a little hacking.
(difficult to solder to nichrome wire)
CAUTION : Hobby Chemist, not Professional or even Amateur
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draculic acid69
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Solder usually won't survive the high temperature. I've heard of silver solder taking
900 'c to apply but silver solder isn't cheap and these things are made quite cheaply(usually)
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Mateo_swe
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You can use crimping to connect the nicrome wires in the new sleeve to the electrical wires in the mantle.
Get some crimp tubes, they are just small metal tubes that you insert the nicrome wire in the tube end and use a crimper or any flat pliers to
collapse the tube squeezing the nicrome wire so its get stuck in the end of the crimp tube.
Do the same in the other end of the crimp tube with the other wire from the mantle.
Any store that sell electricians tools have crimp tubes and the crimp tool.
Or you can use a heat resistant ceramic connection block with screws, that is the optimal solution if there is room for it in the mantle.
Remember than unisolated wires cant touch any metal parts.
Threre is insulation tubes that are heat resistant one can use on the connections.
They are made of some fiberglass like material.
[Edited on 2022-7-15 by Mateo_swe]
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ManyInterests
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Oh fucking hell. Sorry for my language, but it seems like my 2nd (400$) heating mantle is going through the same thing.
I used a 2 liter boiling flask to boil 1 liter of drain cleaner. Everything seemed like it was going fine until apparently it had some sputtering and
sprayed acid all over the place. The mantle seemed Ok. But I obviously needed to wipe it down. I used sanitary wipes and water to clean it. The damage
seemed superficial, but when I tried to turn it on today to evaporate down some 3% H2O2 I heard hissing and it seemed like the same problem is
happening again. Part of the wire was starting to turn visibly red beneath the surface.
I shut it down immediately and the hissing stopped. I hope I didn't short or burn out the wires like last time.
I poured bicarbonate water all over it, rubbed it down some more, then poured another 1.5 liters (in parts) of distilled water since I was told that
bicarbonate water is electrically conductive. Right now I am waiting for my mantle to air-dry. the sleeve is still wet and moist and I dare not try to
turn it on, even for a second, least I trigger another short and fry the wire.
I am so damn upset at this. It's been one thing after another and this is very expensive equipment. Brand new, too. I wouldn't be too upset if it is
something I had for a while... but like I said, it's brand new! I barely got to use it and I have so many things I need to make it work for.
I learned that the whole 50% volume of the flasks is no good. It might as well work for 1 liter boiling flasks, but not 2. From now on I never boil
than 500ml of drain opener. But that is neither here nor there when my new mantle's status is uncertain.
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VeritasC&E
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Maybe you could have a cheap mantle (like a sleeve surrounded by glass fiber insulation in a clay pot) to perform those occasional and risky high
temperature distillations; and keep the real mantles for more standard/gentle stuff?
[Edited on 25-7-2022 by VeritasC&E]
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ManyInterests
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Some good news.
My 2 liter mantle has been repaired. I soaked it in distilled water and dried it. Then washed it again and let it dry mostly on its own before using a
hair dryer to dry it further.
Then I turned it on. I heard or saw nothing of any shorts or flaring. But obviously a lot of water vapor came out because of the water starting to
evaporate. I let it run and brought some water to boil in a boiling flask. Eventually it fully dried up.
I gave it a final test with boiling a little sulfuric acid (only 250ml this time and in my 2 liter flask) and it came to a rolling boil. This means it
did not lose any of its heating ability. Nor was the stirring affected.
I'm quite glad that my 2 liter mantle is safe.
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