<p>You can use kapton tape, <a href="https://www.seemecnc.com/collections/parts-accessories/products/small-ptfe-tubing-per-foot" rel="nofollow noreferrer">small PTFE tube</a>, or <a href="http://rads.stackoverflow.com/amzn/click/B00KBSWRDO" rel="nofollow noreferrer">silicone tape</a>. I use PTFE on my delta printer (I do have a silicone tape wrapped around my heat block, but that's to help with keeping the heat in the block, not for eletrical insulation (although it would work for that)). These will all handle the temperatures of your heat block fairly well.</p>

CC BY-SA 3.0
2017-05-09T18:16:18.897Z
I was thinking about getting a custom fibre glass part made. Do you think this is worth it? Many thanks, Thomas
Vosem Media
CC BY-SA 3.0
2017-05-16T16:32:33.573Z
I was going to go with PTFE but it only goes up to 204C so I'm not sure now... Thanks for all the help though
Vosem Media
CC BY-SA 3.0
2017-05-09T17:56:11.013Z
2017-05-09T17:56:11.013Z
Howler
<p>You could use Kapton tape to tape the thermistor. It is usually the best option for sticking something onto the hotend or on the heat block. You will also have less trouble since it is very thin.</p>

<p>Note that if you use Kapton tape, you should use several layers of it for added insulation.</p>

CC BY-SA 3.0
2017-05-09T17:26:28.183Z
So it will not melt on the heat block?
Vosem Media
CC BY-SA 3.0
2017-05-09T18:56:29.053Z
Kapton should be good to 400 °C but your mileage may vary depending on where you bought it.  The Ebay special Kapton may just be orange tape, who knows...
tjb1
CC BY-SA 3.0
2017-05-09T19:41:59.150Z
Well it can melt...its just no hotend on this planet could get hot enough to melt it. As @tjb1 said, it melts at 400 °C.
Kiro
CC BY-SA 3.0
2017-05-09T17:16:47.433Z
2017-05-09T17:16:47.433Z
Kiro
<p>Ok, so I think I have found the answer. You can get cotton wraps for print heads with some Kapton tape on them, see <a href="http://www.ebay.co.uk/itm/10Pcs-3mm-Thickness-3D-Printer-Heating-Cotton-Hotend-Nozzle-Heat-Insulation-/391778166929" rel="nofollow noreferrer">10Pcs 3mm Thickness 3D Printer Heating Cotton Hotend Nozzle Heat Insulation</a>. I think this will work best as long as it doesn't catch on fire. </p>

<p>Please let me know if there is a better alternative but for now I will use these. </p>

CC BY-SA 3.0
2017-05-10T15:36:23.887Z
2017-05-13T19:41:47.783Z
2017-05-13T19:41:47.783Z
Vosem Media
<p>For an illustration of how to employ the Kapton tape, that is mentioned in the answers from Harvey Lim  and Howler, watch <a href="https://www.youtube.com/watch?v=0EIFIAWiPdU&amp;t=1290" rel="nofollow noreferrer">How to build a RepRap Prusa i3 (Assembly 7)</a> at 21:30:</p>

<p><a href="https://i.sstatic.net/IEr3y.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/IEr3y.png" alt="Kapton tape on hotend"></a></p>

<p>From <a href="https://www.youtube.com/watch?v=0EIFIAWiPdU&amp;t=910" rel="nofollow noreferrer">15:10</a> the heater and thermistor is connected up, you may find this also useful. Note that, at <a href="https://www.youtube.com/watch?v=0EIFIAWiPdU&amp;t=1245" rel="nofollow noreferrer">20:45</a>, the heatshrink is only used over the soldered connection, and <em>not</em> all the way up to the heatblock:</p>

<p><a href="https://i.sstatic.net/i2k2W.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/i2k2W.png" alt="Heatshrink on thermistor"></a> </p>

<p>Also, more pertinent to your printer, from <a href="https://pevly.com/anet-a8-3d-printer-review/" rel="nofollow noreferrer">Anet A8 Review – Best cheap 3D Printer?</a>, see that the thermistor wires are also wrapped in Kapton tape in this photo:</p>

<p><a href="https://i.sstatic.net/mjVNQ.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mjVNQ.jpg" alt="Thermistor wires are also wrapped in Kapton tape"></a></p>

<p>Note that the Kapton tape is wrapped around the wires, almost right up to the thermistor, and will be touching the heating block, when the thermistor is inserted into the hole - there is no problem of it melting, due to its high melting point.</p>

CC BY-SA 3.0
2017-05-10T06:58:19.893Z
2017-05-14T21:07:53.670Z
2017-05-14T21:07:53.670Z
Greenonline
<p>I have had many problems with my heat shrink for the thermostat on my Anet A8 melting from the heat block. </p>

<p>Is there a way I can insulate my wires from heat but still have enough room to put the thermistor into the block?</p>

CC BY-SA 3.0
2017-05-11T04:05:01.790Z
I've added another photo to my answer, that you may find very useful.
Greenonline
<heat-management><thermistor>
How can I insulate my thermistor?
Vosem Media
# How can I insulate my thermistor?

(Asked by: username_0 on 2017-05-09)

I have had many problems with my heat shrink for the thermostat on my Anet A8 melting from the heat block.

Is there a way I can insulate my wires from heat but still have enough room to put the thermistor into the block?

**Tags:** heat-management, thermistor
> **Comments:**
> **username_1**: I've added another photo to my answer, that you may find very useful.  

---

## 4 answers

### Answer by username_1 on 2017-05-10. Score: 2 | Accepted answer

For an illustration of how to employ the Kapton tape, that is mentioned in the answers from Harvey Lim and Howler, watch [How to build a RepRap Prusa i3 (Assembly 7)](https://www.youtube.com/watch?v=0EIFIAWiPdU&t=1290) at 21:30:

[![Kapton tape on hotend](https://i.sstatic.net/IEr3y.png)](https://i.sstatic.net/IEr3y.png)

From [15:10](https://www.youtube.com/watch?v=0EIFIAWiPdU&t=910) the heater and thermistor is connected up, you may find this also useful. Note that, at [20:45](https://www.youtube.com/watch?v=0EIFIAWiPdU&t=1245), the heatshrink is only used over the soldered connection, and *not* all the way up to the heatblock:

[![Heatshrink on thermistor](https://i.sstatic.net/i2k2W.png)](https://i.sstatic.net/i2k2W.png)

Also, more pertinent to your printer, from [Anet A8 Review – Best cheap 3D Printer?](https://pevly.com/anet-a8-3d-printer-review/), see that the thermistor wires are also wrapped in Kapton tape in this photo:

[![Thermistor wires are also wrapped in Kapton tape](https://i.sstatic.net/mjVNQ.jpg)](https://i.sstatic.net/mjVNQ.jpg)

Note that the Kapton tape is wrapped around the wires, almost right up to the thermistor, and will be touching the heating block, when the thermistor is inserted into the hole - there is no problem of it melting, due to its high melting point.


---

### Answer by username_2 on 2017-05-09. Score: 4

You can use kapton tape, [small PTFE tube](https://www.seemecnc.com/collections/parts-accessories/products/small-ptfe-tubing-per-foot), or [silicone tape](http://rads.stackoverflow.com/amzn/click/B00KBSWRDO). I use PTFE on my delta printer (I do have a silicone tape wrapped around my heat block, but that's to help with keeping the heat in the block, not for eletrical insulation (although it would work for that)). These will all handle the temperatures of your heat block fairly well.

> **Comments:**
> **username_0**: I was thinking about getting a custom fibre glass part made. Do you think this is worth it? Many thanks, Thomas  
> **username_0**: I was going to go with PTFE but it only goes up to 204C so I'm not sure now... Thanks for all the help though  

---

### Answer by username_3 on 2017-05-09. Score: 2

You could use Kapton tape to tape the thermistor. It is usually the best option for sticking something onto the hotend or on the heat block. You will also have less trouble since it is very thin.

Note that if you use Kapton tape, you should use several layers of it for added insulation.

> **Comments:**
> **username_0**: So it will not melt on the heat block?  
> **username_4**: Kapton should be good to 400 °C but your mileage may vary depending on where you bought it.  The Ebay special Kapton may just be orange tape, who knows...  
> **username_3**: Well it can melt...its just no hotend on this planet could get hot enough to melt it. As @tjb1 said, it melts at 400 °C.  

---

### Answer by username_0 on 2017-05-10. Score: 2

Ok, so I think I have found the answer. You can get cotton wraps for print heads with some Kapton tape on them, see [10Pcs 3mm Thickness 3D Printer Heating Cotton Hotend Nozzle Heat Insulation](http://www.ebay.co.uk/itm/10Pcs-3mm-Thickness-3D-Printer-Heating-Cotton-Hotend-Nozzle-Heat-Insulation-/391778166929). I think this will work best as long as it doesn't catch on fire.

Please let me know if there is a better alternative but for now I will use these.


---

