Downloaded a mold for e3d hotend (silicone) to isolate it. Now trying to harden it faster with watervapor and heat xD any suggestions on how to do it better? Its 350deg celsius rated silicone but cant find silicone thats more runny to easier mold it…
I thought molding silicone used various chemical catalysts in order to effect a cure. Platinum cure is one term that comes to mind. The different products will have differing cure times as well as different viscosity per type. The thicker ones are more prone to embedded bubbles, which may not be a factor in your application.
RTV (room temperature vulcanizing) silicone types do not require catalyst for curing. Some release acetic acid and should not be used where such chemical reactions would be undesirable, i.e., electronics. Vinegar contains acetic acid, making it easy to determine what type of RTV silicone is in use, or rather if it’s not.
I’d seen reference many moons ago of consumer-grade aerogel being available. It has an extremely high temperature isolation. I sent a contact request via the web page (lost in my memory) for pricing and quantities/sizes but never heard back. A block of aerogel with an external mechanical support would likely mean zero heat transfer. The link I just located (http://buyaerogel.com) shows a temperature limitation of 80 deg C, which makes that particular product unsuitable.
care to tell us where you found that mould from?
E3D-V6 Heat Shield Silicone Mold found on #Thingiverse E3D-V6 Heat Shield Silicone Mold by KronBjorn - Thingiverse
What purpose does wrapping the heater block in silicone serve? Is it to better maintain the termperature (more stability) or to prevent the heat within from affecting the print, or both?
The Temperature is more stable an you need lower Temps. No sticking filament on the Heaterblock.
@Fred_U Well yes both
naaaaaa That are not the positives that I would talk about… The biggest advantage is the very much reduced heat radiation into the printed part during the print. Secondary effects are: less delicate to blowing onto the heaterblock and it stays “cleaner” (speak: filament doesn’t get baked on it). Needing lower temp is definitively not true. It is just a “windshield” for badly airflow, a heatshield for small prints and a 'dirt-repellant" thing for the heaterblock. What A-rating has your silicone?
I just get some aquarium sealant and slather it on.
I am using PLA and E3Dv6 Lite hot ends, so only 245C is my max.
Add some talcum powder or gypsum powder or corn starch to the silicone and mix well. Or you can add a few drops of water based hobby paint and mix well. The paint also acts like a nice colourant and it’s water contents causes the silicone to cure solid throughout the mould.
Add naptha or common Zippo - type lighter fluid to the silicone to thin it down.
@VolksTrieb thanks