Posted by Neil Wyatt on 21/01/2018 19:53:07:
My advice is to make sure you use fresh cat litter…

Neil
Not at all. Dung is good stuff in moulding sand – it helps bind it together. And it was the material of choice for mending marine boilers.
"Aye, my lad, I know. You'll be thinking I'm decrepit . My mind's wandering through sweating round here, when I'm past it, to find that in-take to the vacuum. But I'm telling ye. It was horse dung and good stuff too, to stop weeps in the boilers, those days."
Only real men smear dung these days because you wimpy lot like keeping your pretty hands clean. If you're serious about quality you have to use the real thing. No excuses – get stuck in, dung and sand has to be well-kneaded. No gloves, the texture tells you when it's ready to use.
Man up. Don't listen to experts, they know nothing. Health and Safety gone mad I tell you. A dose of E.coli never hurt anybody…
Dave