Science/Engineering/Technical forums

Hi,

Is there any 'simple' way of casting ceramics? Something that would act as a refactory ceramic I can embed electrodes in?

(Bear in mind I am in UK, so whatever you can get from every corner store in the US is something no stockist in the whole of the UK will have!)

I can get a hold of zircon flour and colloidal silica, but I've never worked with them before. Can I use these in some manner to make a successful ceramic casting? Strength and dimensional accuracy are not key attributes, so long as they don't crumble into fine dust.

Chris
I found a jar of stuff labelled Soreson cement @ work the spelling of Sorenson was not correct but a WEB search will get it right

you mix this with water and bake @ moderately low temps (around 250 degrees C from memory)to get a metal glass seal. They used this a few years back at work for high voltage feedthroughs into vacuum for what its worth.

Let us know how that works out. I tried some stuff from McMaster for this, and it leaked badly after only a small thermal cycling. It was supposed to be slightly flexible to account for the inevitable tempco mismatch with just about anything else, but easily failed. This is what led me to do the machined O ring seals to pyrex stuff, as I could never get that to work decently.

Try ;- http://www.2spi.com/catalog/vac/vacleak.shtml

Wasn't quite what I was looking for, John, but I've now found what looks like what I am after and, surprise surprise, it's made here in UK! So I have bought a tub of this stuff;
http://shop.vitcas.com/premium-fire-cement-12-p.asp

It doesn't look quite as good as;
http://shop.vitcas.com/vitcas-mouldable ... g-20-p.asp

but cheaper so I thought I'd give the first one a go first. That 'cement' also looks a bit more mouldable to fine detail than the second.

There are other similar products on that website too, with slightly different properties, worth a look at.

Chris - you can use the Vacseal to coat a cement job to secure a seal if needed.