Can anybody recommend a high temperature thermal insulation which I could use to replace cuttlefish bone that I presently use in my hot ends. I have heard about cellular glass but know nothing about it - can it be cut into shapes with 2mm thick walls, where can it be purchased etc.. Are there any other similar materials? The existing cuttlefish insulators are shown in the photo below in white - they are protected in a box made from thin brass sheet which is also the guide for cooling air to the print. [attachment 80656 20131109_164336.jpg] The requirement has arisen because I want to fit interchangeable nozzles to the hot ends on my printers. Cuttlefish bone has many exceptional properties but it is unbelievably fragile and changing a nozzle would turn it from a solid to a powder quite rapidly. Mike https://reprap.org/forum/read.php?1,683322,683322#msg-683322 Mon, 13 Jul 2026 08:22:49 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,683322,686842#msg-686842 https://reprap.org/forum/read.php?1,683322,686842#msg-686842 [attachment 81316 2016-07-1422.57.35.jpg]
The only thing is it takes about 4-5 days to set as there is only a tiny bit of air (and moisture which it needs to set) getting to it through a 3d printed mould which is in this case, thankfully porous.

I've made a mould for a v5 hotend based on Sreks design (above) just trying it out now, but using the two part mix addition cured silicone instead (much messier but a lot quicker).
[attachment 81343 2016-07-1520.04.39.jpg]

Seems it does work, have hosted it here, thanks to Srek for the original design/idea.]]> DjDemonD General Thu, 14 Jul 2016 18:05:14 -0400 https://reprap.org/forum/read.php?1,683322,684791#msg-684791 https://reprap.org/forum/read.php?1,683322,684791#msg-684791 Unix Shell Scripting Training | Angularjs Training | Informatica Training | Tableau Training | Hadoop Training]]> kitharington General Thu, 07 Jul 2016 08:14:27 -0400 https://reprap.org/forum/read.php?1,683322,684747#msg-684747 https://reprap.org/forum/read.php?1,683322,684747#msg-684747 DjDemonD General Thu, 07 Jul 2016 06:11:26 -0400 https://reprap.org/forum/read.php?1,683322,684736#msg-684736 https://reprap.org/forum/read.php?1,683322,684736#msg-684736 [b.bonkers.de]
[b.bonkers.de]
[b.bonkers.de]
Try using a separation agent like vaseline or PTFE spray, due to the fine layer structure of 3D printed molds the silicone can stick quite good.
The silicone used is advertised for tin casting, you will find a source in germany in the links above.]]> Srek General Thu, 07 Jul 2016 05:13:09 -0400 https://reprap.org/forum/read.php?1,683322,684727#msg-684727 https://reprap.org/forum/read.php?1,683322,684727#msg-684727 www.thingiverse.com]

When I checked the actual conductivity with some silicone rubber I was pleasantly surprised and think that it would do well for most hot ends. Having said that, my hot ends are a little unusual as the cooling air for the print is directed through an air ring around the nozzle and low thermal conductivity was more important than toughness. Using the best engineering "wild guess" strategy, I think that ceramic wool has about one tenth of the conductivity of silicone rubber.

Mike]]> leadinglights General Thu, 07 Jul 2016 04:26:28 -0400 https://reprap.org/forum/read.php?1,683322,684715#msg-684715 https://reprap.org/forum/read.php?1,683322,684715#msg-684715
If I was going to do this, I'd design and print a mould to fit around the hotend, then fill it with high temperature silicone. Then remove the mould. It seems easy enough in theory. The only thing that might save a lot of trial and error is a recommendation on which silicone to use and to know whether when it needs to be removed, how straightforward this is.]]> DjDemonD General Thu, 07 Jul 2016 03:51:34 -0400 https://reprap.org/forum/read.php?1,683322,684622#msg-684622 https://reprap.org/forum/read.php?1,683322,684622#msg-684622 animoose General Wed, 06 Jul 2016 15:05:16 -0400 https://reprap.org/forum/read.php?1,683322,684616#msg-684616 https://reprap.org/forum/read.php?1,683322,684616#msg-684616 www.ebay.co.uk] it turned out to be a sort of woolen batting made from a ceramic fiber. It cuts easily and cleanly with a sharp scalpel so I was able to form it into a box with chamfered edges which I folded round the heater block. Pictures below show the parts including the cut insulation, the insulating box assembled with Kapton tape and the hot end assembled with shroud and replaceable nozzle.
[attachment 80868 20160706_1612161.jpg][attachment 80874 20160706_1641241.jpg][attachment 80876 20160706_1653231.jpg]

Mike]]> leadinglights General Wed, 06 Jul 2016 14:47:27 -0400 https://reprap.org/forum/read.php?1,683322,684071#msg-684071 https://reprap.org/forum/read.php?1,683322,684071#msg-684071
With the proper thickness, Kapton can hold it without problems.]]> Dyze_Design General Mon, 04 Jul 2016 14:51:10 -0400 https://reprap.org/forum/read.php?1,683322,683616#msg-683616 https://reprap.org/forum/read.php?1,683322,683616#msg-683616 www.ebay.co.uk] I've got some mk8 hot ends with this material applied but I have never used them.]]> DjDemonD General Sat, 02 Jul 2016 15:14:01 -0400 https://reprap.org/forum/read.php?1,683322,683529#msg-683529 https://reprap.org/forum/read.php?1,683322,683529#msg-683529
Mike]]> leadinglights General Sat, 02 Jul 2016 09:15:29 -0400 https://reprap.org/forum/read.php?1,683322,683366#msg-683366 https://reprap.org/forum/read.php?1,683322,683366#msg-683366 www.amazon.com]. I have some but have not tried it yet.]]> animoose General Fri, 01 Jul 2016 16:08:00 -0400 https://reprap.org/forum/read.php?1,683322,683354#msg-683354 https://reprap.org/forum/read.php?1,683322,683354#msg-683354 Srek General Fri, 01 Jul 2016 15:29:23 -0400 https://reprap.org/forum/read.php?1,683322,683352#msg-683352 https://reprap.org/forum/read.php?1,683322,683352#msg-683352 Can you tell me the make and grade of the heat resistant silicone that you used?

Mike]]> leadinglights General Fri, 01 Jul 2016 15:24:05 -0400 https://reprap.org/forum/read.php?1,683322,683348#msg-683348 https://reprap.org/forum/read.php?1,683322,683348#msg-683348 [forums.reprap.org]]]> Srek General Fri, 01 Jul 2016 14:59:36 -0400 https://reprap.org/forum/read.php?1,683322,683338#msg-683338 https://reprap.org/forum/read.php?1,683322,683338#msg-683338 Origamib General Fri, 01 Jul 2016 14:25:28 -0400 https://reprap.org/forum/read.php?1,683322,683322#msg-683322 https://reprap.org/forum/read.php?1,683322,683322#msg-683322
The existing cuttlefish insulators are shown in the photo below in white - they are protected in a box made from thin brass sheet which is also the guide for cooling air to the print.

[attachment 80656 20131109_164336.jpg]

The requirement has arisen because I want to fit interchangeable nozzles to the hot ends on my printers. Cuttlefish bone has many exceptional properties but it is unbelievably fragile and changing a nozzle would turn it from a solid to a powder quite rapidly.

Mike]]> leadinglights General Fri, 01 Jul 2016 13:04:56 -0400