Hotend won't stay hot, needs insualtion.

I am printing PETG at ~260° and about 2 minutes after printing starts the temperature slowly falls and eventually fails.

I have an E3D V5 hot end and cannot find a silicone sock for it. I have tried wrapping it in tinfoil, but that eventually falls off and ruins prints.

Does anyone know of a way to insulate a hot end with common materials?

That doesn't sound like an insulation problem but a temperature control problem or even a defect of the heater.
Or are you pointing a fan directly on the heatblock?

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

On my first printer I made my own silicone sock.

Go to local housewares store, buy "silicone baking tray liner" -- basically a sheet of silicone ~2mm thick.

Cut a strip about the height of the heater block. Cut another small piece to fit underneath, and a U shaped piece for the top, around the throat.

Tape onto the heater block with kapton tape.

Use the rest of the sheet for the underside of the heated build plate, because why not?

It wasn't pretty, but it was functional, and never caused me a problem after that.

Edit: Aluminum foil, being a good conductor will absolutely not help with keeping heat, if anything you just added an extra heat sink to your block.

If you are no longer able to keep the temperature of your hot end high enough, you are losing heat somewhere. You will lose some power melting the filament, and lose some to the air. A heat sock will reduce the amount you lose to the air, but unless you have something blowing on the heat block, a reasonable heater should be able to keep up. A more powerful heater might be the solution that you need. If you are running at 12V, going with a 24V system could be helpful (Though that also involves changing out a bunch of other things. It may be possible to just get a more powerful heating element.

Edited 1 time(s). Last edit at 07/13/2018 11:55AM by SupraGuy.

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MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.

Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts

You could also try and pour your own silicone sock. I made one for larger hotends(2mm+ nozzles)
Making the negative is rather easy. Just print it.
To have a very close fit I made my positive out of aluminium. But a printed positive will do nicely too.

You need to find silicone that withstand that kind of heat.
The brand I bought can handle temp up to 300°C(Were I live 'Vosschemie' do sell it)

Turns out I had a crappy heater cartridge, Replaced and seems okay for now.

On a side note: aluminum foil can help keeping temperature stable IF it doesn't touch the hotend. Put baking paper or cotton first, than the foil. Works very well.