Oozing silicone socks

[Erik]

I experience the silicone sock to ooze out hard, clearish drops onto the print bed from time to time.
When I removed the sock today, it was britle and hardened with cracks and a molten part.
Happened with an original micro swiss silicone sock.

Has anyone else experienced this and has eventually a fix against it?

[Ender5r]

Are you certain you don't have filament oozing out of the joint between the heater block and the tube that joins the heater block to the heat sink above?

[Erik]

No filament leak, it comes from the silicone sock itself.
It is a quite clear substance that hardens to a glass like substance.
The sock itself has lost substance
I am thinking about replacing the sock with some aerogel sheet.

[Ender5r]

That is a silicone sock for sure?? How hot is the hotend? I have to think it's a defective sock. Silicone rubber isn't supposed to melt until it reaches 1400C.

[Alan]

That is a silicone sock for sure?? How hot is the hotend? I have to think it's a defective sock. Silicone rubber isn't supposed to melt until it reaches 1400C.

Agreed, there is something else going on. Leaking plastic or maybe bad kapton tape (Edit: I've seen some cheap stuff from China that was like asbestos with a yellowish clear plastic tape on the outside).

Cheers

[Erik]

It is a genuine micro swiss sock and I printed only PLA, mostly at 190°C, max. 220C.
Took some time until I realised it came from the silicone sock.
Maybe it was a monday piece, I'll try it first with a new sock.

[Erik]

Agreed, there is something else going on. Leaking plastic or maybe bad kapton tape (Edit: I've seen some cheap stuff from China that was like asbestos with a yellowish clear plastic tape on the outside).

Cheers

I was thinking about that, too.
I replaced the temp sensor the other day and the kapton was ok, I replaced it with a piece of 3M high temp silicone tape.

There are different types of silicone (mixtures). As the blue color.

[Ender5r]

Well, I guess I will find out about Micro Swiss blue socks very soon, since I just installed a Micro Swiss direct drive extruder on my Ender 5.

[Alan]

Maybe it was a monday piece, I'll try it first with a new sock.

Hopefully this is it. You could print using the hotend without a sock (after a PID tune) as a visual check for problems. Regardless, Micro Swiss makes quality hotends. Let us know the solution!

Cheers

P.S. -- I see you replaced the thermistor before the problem. Any chance the thermal paste used could be part of the problem?!

[akc]

While silicone socks are good as an insulator and protector for the heat block, I believe they are considered a wear item by the manufacturers that use them. There are many online listings for 3d printing silicone socks on amazon, ebay, and even walmart. I think the repeated heating and cooling of the sock causes them to eventually deteriorate such as shown by Erik.

This reminds me of the old saying "nothing lasts forever".

[MambaRoja]

How long should they last? Any advantages to WAHHING 10PCS 2mm thick Heater block cotton Safe Working Temp less 300°C For 3D printer Hotend https://amazon.com/gp/product/B01LAY...?ie=UTF8&psc=1

[Alan]

How long should they last?

That's a good question and why I find the OP's issue is puzzling. Outside of accidents, I cannot imagine needing to ever replace one. But, because they are so inexpensive, I keep a few spares on hand. I think any thickness can work provided there is clearance for it (especially between the sock and the print bed). My spares are OEM equivalents so I don't need to PID tune if I'm in a hurry, fwiw.

Cheers

[Ender5r]

In a year and a half, I have not had to replace any of mine.