"The weight of the metal might be too great for it's thickness and it could buckle and collapse," Allan said. "Or it might not flow properly and there could be bubbles. Or once it's finished it might just not work. That happens sometimes. Or it might all go really well and people might just look at it and say 'that's just - fucking horrible' and it might stand at the back of my workshop for years gathering dust until I need the space."
He grinned, not particularly bothered. No point worrying until it happened but it was wise to be aware of the pitfalls.