But I would recommend building ligh dobsonian to everyone. Mirrors are cheap and rest is just wood or aluminium. My 10" has 20 pounds and is flyable.
One needs to maintain a clean-room environment, both for the protection of the mirror from dust, and of yourself from the abrasives.
That's crazy talk, and an impossibility. The stuff gets everywhere. It is a messy process. Here is a particularly messy example. https://www.youtube.com/watch?v=cukjxWCPVeg
That video shows the kind of clean-room I meant. Gloves to reduce contact, container to avoid spills. I also used a cloth over my nose and mouth when dealing with the finer grits (in dry form).
It need not be as clean as a fab, but it sure needs to be cleaner than a typical workshop or garage.