Dudes about thermal paste....

fma

Thermal paste is a very bad heat conductor: aluminium is 240 W·m⁻¹·K⁻¹, good thermal paste is... 3 W·m⁻¹·K⁻¹!!! 2 orders of magnitude less!

It should only be used to fill tiny little air gaps, remaining after polishing surfaces. On processors, the best way is to have very flat/polished surfaces, and apply strong pressure. Thermal paste should be put in a very thin layer.

I often see people putting way too much paste, reducing the heat conductivity instead of improving it! I never put thermal paste or grease in any hotend, and never had any jam issues.

sebkritikel

I use (and Slice Engineering recomends) Boron Nitride paste with the Mosquito Hotend; I have personally applied it to the thermistor and heater cartridges, although they have some additional application insight listed on their website:

Slice Engineering™ recommends Boron Nitride Paste for use in hotends of any brand. For
decades it has been used as a “heat transfer and release coating” for industrial cartridge
heaters. Use it to improve heat transfer:
    ● From the cartridge heater to the hot block, to extend the life of the cartridge heater
    ● From the hot block to the temperature sensor, to shorten response time and improve
       accuracy of temperature measurements
    ● From the hot block to the heat break to improve high flow rate performance when
       printing with large diameter nozzles
    ● To improve the seal between nozzle and heat break

Boron Nitride Paste may be used generally, in assemblies operating in temperatures up to
1000°C, as an electrically insulative heat transfer and anti-seize compound.

Listed thermal conductivity of 31.4 W/mK

dc42

Boron nitride (hexagonal) is good stuff, I used to make waveguide CO2 lasers out of it. Few other materials have such good thermal conductivity yet are electrical insulators.

grizewald

Agreed on the utility of boron nitride paste. I also use it on the threads of the nozzle in my Mosquito hot end and it ensures that removing the nozzle is pain free every time.

I can't quantify it, but it feels like it has also made steel nozzles a little less reluctant to getting up to temperature and staying there.

The only thing to watch out for is if there's any excess at the ends of the holes for the heater cartridge and temperature sensor, it tends to fall off and get incorporated into whatever you're printing at the time!

Quadcells

Can Boron Nitride Thermal Paste be used on the heat break of the E3D Chimera + hotends?
Is it better to use the the grease they supply. Would anyone know the thermal conductivity of the E3D grease?

PaulHew

I use Arctic on my heat breaks.
Slice recommend Nitride, but speaking to a dealer he use Arctic also.

HTH Paul

Quadcells

@PaulHew Articsilver 5 on the Chimera?

Quadcells

@PaulHew asking because I have Articsilver 5, HY410 and Boron Nitride Thermal Paste , but no E3D thermal grease.

PaulHew

E3D sell the same stuff for all of their hotends, AFAIK.
I am using Arctic MX-4 compound

A Former User

I used galium based "liquid metal" for computers as core of the heatsink is copper but trying them out on the 3d printers with aluminium parts is a bad idea... no I heard that mosquito comes with plated copper and steel parts so no aluminium there, also I know there are copper heater blocks for e3d and non copper / brass nozzles so it might work there too .. anyhow, if there's aluminium the LM compounds are dangerous, if it's copper they are best conductors compared to everything I ever tried (have not tested Boron Nitride)