What are you sealing in the resistor and thermistor with on your block style heater core? I noticed that Nophead uses fire cement, I saw someone use high temp RTV and another used high temp epoxy. What is everyone using? Also what are you insulating the bare wires with? I assume a fiberglass braid is used. Where would one order that from? https://reprap.org/forum/read.php?70,91290,91290#msg-91290 Thu, 13 Aug 2026 05:51:50 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?70,91290,91731#msg-91731 https://reprap.org/forum/read.php?70,91290,91731#msg-91731
I consider this a pretty good and versatile material for hot end purposes. Its very cheap, probably cheapest for this temperatures. It sticks good enough to almost anything (metal), just makes just a little fume when curing first time. When no longer needed it can be "peeled" off with a cutter blade.

I also use it to cover the entire heated block (not just for thermistor) - hoping for some kind of insulation.
And i use it to cover the wires of everything there, thermistor and resistors aswell - hoping for both insulation and less temperature-oxidation of wires, especially for resistors leads in this case.

P.S.
Inside in between the heater and resistor i use just 1-2 turns of kapton tape, as i had a short at some point between my 2 resistors and the heated block material.]]> NoobMan Plastic Extruder Working Group Sun, 24 Jul 2011 07:23:07 -0400 https://reprap.org/forum/read.php?70,91290,91491#msg-91491 https://reprap.org/forum/read.php?70,91290,91491#msg-91491 brnrd Plastic Extruder Working Group Thu, 21 Jul 2011 17:15:29 -0400 https://reprap.org/forum/read.php?70,91290,91467#msg-91467 https://reprap.org/forum/read.php?70,91290,91467#msg-91467
The compound I am using is rate to 240C. I don't really care if it dries out though. It does seem to work at filling any voids, which are probably not that big to begin with.]]> jcabrer Plastic Extruder Working Group Thu, 21 Jul 2011 12:28:33 -0400 https://reprap.org/forum/read.php?70,91290,91402#msg-91402 https://reprap.org/forum/read.php?70,91290,91402#msg-91402 brnrd Plastic Extruder Working Group Wed, 20 Jul 2011 21:59:31 -0400 https://reprap.org/forum/read.php?70,91290,91354#msg-91354 https://reprap.org/forum/read.php?70,91290,91354#msg-91354 I use aluminum encased power resistors in my hot end. Although they have screw mount holes for M2, I just put a bit of heat sink compound on the flat bottom, and fasten it with kapton tape.

The thermistor is similarly mounted from the opposite side of the block. I spread the wires out in a Y shape, and make them parallel about 1/4" apart, and then I wrap them in kapton right up to the glass bead. I place the glass in direct contact with the nozzle and block where they meet, and wrapp the entire thing in several layers of kapton. The tape is a good insulator, that keeps the block hot, but allows the fan to cool other parts of the extruder without draining too much heat (if you use fans, I don't).]]> jcabrer Plastic Extruder Working Group Wed, 20 Jul 2011 12:27:59 -0400 https://reprap.org/forum/read.php?70,91290,91340#msg-91340 https://reprap.org/forum/read.php?70,91290,91340#msg-91340
For the thermistor wires I have been sandwiching the wires between two layers of Kapton.]]> Sublime Plastic Extruder Working Group Wed, 20 Jul 2011 11:07:50 -0400 https://reprap.org/forum/read.php?70,91290,91295#msg-91295 https://reprap.org/forum/read.php?70,91290,91295#msg-91295
The resistor can also be jammed in with AL foil for good heat conduction. You have get the number of turns just right. Too thin and it falls out, too thick and it damages the resistor.

I haven't found a source of fibreglass braid. I used some a long time ago that I recovered from something else but it soon blackened. I currently use PTFE sleeving.]]> nophead Plastic Extruder Working Group Wed, 20 Jul 2011 04:13:16 -0400 https://reprap.org/forum/read.php?70,91290,91290#msg-91290 https://reprap.org/forum/read.php?70,91290,91290#msg-91290
I noticed that Nophead uses fire cement, I saw someone use high temp RTV and another used high temp epoxy. What is everyone using? Also what are you insulating the bare wires with? I assume a fiberglass braid is used. Where would one order that from?]]> SCphotog Plastic Extruder Working Group Wed, 20 Jul 2011 03:34:35 -0400