Thermal grease for PT100 and heater?

[avogra 68]

Hey everyone!

I'm going to install my new Olsson Block today and I was wondering if it is a good idea to add some thermal grease? The installation manual doesn't mention it but it might be helpful. Did you do anything like that?

[Dim3nsioneer 557]

Yes, I recommend it. It's never wrong to have a good thermal contact between a heater, a heat conducting element (heater block) and a temperature sensor.

[avogra 68]

I have poked around and came to the conclusion that thermal grease is hard to find for temperatures above 140..180°C. Instead I think of copper paste now Is that even more stupid or just perfect or... ?

Edited February 9, 2016 by Guest

[avogra 68]

Thank you @Dim3nsioneer. So you just use conventional thermal grease like the one you get for computer processors or did you use something more temperature robust?

[Labern 774]

I don't recommend it as it goes hard over time and you wont be able to get the sensor out easily. If you do ever remove the sensor then you have to remove all the grease as the dried up remains end up as a thermal insulator. Its normally for heat sinks that have flat surfaces where it is not a problem.

[avogra 68]

 

@Labern, are you referring to conventional thermal grease or to copper paste?

[Labern 774]

Thermal grease.

Copper paste can also dry out at high temps over long periods but not as bad.

[Dim3nsioneer 557]

Oops... I should have mentioned that I use copper paste not thermal grease. It's suitable up to 300 °C.

[avogra 68]

Ok, I will give the copper paste a shot Thank you both!

Don't know which answer to mark as best :( I think no single one is helpful directly under the question. Is that ok for you?

[neotko 1,417]

What about copper grease? It shouldn't dry and can go 1000C. Like the one used on the bed screws and on the steel coupler on um2 hotend.

[Labern 774]

Ok, I will give the copper paste a shot ;)Thank you both!

Don't know which answer to mark as best :(I think no single one is helpful directly under the question. Is that ok for you?

 

Just mark you own post

[Labern 774]

Where I worked we tried Thermal pastes and copper pastes and copper anti-seize grease. Didn't matter what we used it ended up drying out causing issues working in about the same temp ranges. So we settled with using nothing at all.

The oil tends to migrate away leaving the soap in the copper anti-seize. this is ok for bolts but it looses its benefits for temp sensors.

I also remember a few posts of people here who couldn't get their sensors out after using the thermal paste.

[avogra 68]

@Labern, then it probably doesn't make any difference at all :PI didn't get the PT100 out of my old block with only 200 hours printed and maybe 10 hours thereof above 210°C. Anyway, I'm not planning to exchange it in the near future. Installed the 35W heater too at the occasion so I hope I won't have to touch my hotend anytime soon.

@neotko, thats exactly what I did in the end

Edited February 9, 2016 by Guest

[chuck-yanke 10]

I have found the copper grease does not hold up long term. I have used Arctic Silver 5 High-Density Polysynthetic Silver Thermal Compound. You can get on Amazon. After a year of continuous use the probe and heater came out easily.