New thermistor isolation, how?


We are trying to repair an Ultimaker Original+. One problem is a missing resistor isolation. The Ultimaker Original+ prints with up to 260 Degree Celcius.

Which kind of isolation products are suitable to resist the heat and are fitting on the thin wires of the thermistor?


Posted 2017-01-15T14:01:40.907

Reputation: 153

1"Where can I get them" is rather dependent on your location, and on StackExchange, we like to avoid opinion-based answers (such as recommending a particular supplier of a product). – Tom van der Zanden – 2017-01-15T20:08:55.570



The most common choice for insulating thermistors is glass fiber sleeving. It tolerates very high temperatures, and is commonly rated for up to 600 °C.

Teflon is also used but has a rather low upper limit on its working temperature; it shouldn't be used at temperatures exceeding 260 °C - which rules it out for your purpose.

Tom van der Zanden

Posted 2017-01-15T14:01:40.907

Reputation: 14 003

I have never seen FBG sleeving small enough for the hair size wires typical on a thermistor. Do you have a source? I just used Kapton tape. – DLS3141 – 2017-01-16T16:52:43.253

@DLS3141 E3D carries some. – Tom van der Zanden – 2017-01-16T18:04:46.970


I'm not sure if it fits the use you're describing, but Kapton (polyimide) tape is stable to about 400 degrees C. It can also be used as a build surface, so generally useful to have some.

Kapton tape is used all the time for electronic work, both to secure fine wires (for example patch wires on a PCB) and for insulation. It's not so great for thermal insulation since it is thin, but I have my hot-end wrapped in it, and that has saved some burnt fingers.

Sean Houlihane

Posted 2017-01-15T14:01:40.907

Reputation: 3 622


I used Kapton tape to insulate mine.


Posted 2017-01-15T14:01:40.907

Reputation: 21


There are many materials you can use one that came to my mind is this High Temperature & Pressure Sealant and also the best way to apply it so it can be removed easy is this . take a kitchen food very thing nylon cover you know the very thin elastic one or cover the parts with some type of release agent (dont use something that inhibit silicone like sulfur or sulfur containing staff) and apply it over it then when is solid cut it and release it it would be like a glove i hope ;)There are silicone that are really high temp 1000 f to 2000 f good luck :)


Posted 2017-01-15T14:01:40.907

Reputation: 37