throw73849488's comments

Silicosis, but also fine dust is toxic when ingested. It can literally kill your cat or dog!

A bit messy is understatement. And finishing such project without a good guidance is almost impossible. At final stage a few bad moves can destroy week of work! It is setting up newcomers for failure and burnout.

We made our own mirrors, because there was no other option a few decades ago.

But today mirrors are cheap, and they come with aluminum coating and rest of the telescope!