Largest hand made mirror for dob?

[gregted]

Hi all.

I made a 6" f/8 dob with my son many years ago and now live in the country where the skys are dark and clear.

I am thinking of making a much larger dob and was wondering how big i can/should go..

The telescope does not need to be transportable as I am thinking of setting it up permanently.

I can construct a viewing platform so focal length is not an issue.

Is 12 inch suitable or can I go much larger. Maybe 16 inch or even bigger..

What is the largest home made dob?

I am also thinking of silvering my own mirror.. Any advice/instruction?

Great forum by the way.

All the posts i have read have been full of very constructive advice.

[Doc]

At 16" it will need to be around a F4.5 which makes it harder to make a perfect mirror.

[FraserClarke]

Largest homemade (and hand ground/polished mirror) dob I'm aware of is 42-inches...

I'm not sure I'd suggest it as a suitable step-up from a 6-inch though

Silvered mirrors tranish rather quickly, and you'll be looking at redoing the coating every year or so (depending on your local humidity). The quality of commercial Al coatings these days makes it hard to argue against them -- a good coating with a SiO overcoat will last at least a decade, if not more...

[exoplanet]

I appreciate that this is not really the answer to your question, but I saw this the other day whilst researching the same and thought it was these were pretty impressive

Webster Telescopes - Large Dobsonian Telescopes

[Beulah]

I appreciate that this is not really the answer to your question, but I saw this the other day whilst researching the same and thought it was these were pretty impressive

Webster Telescopes - Large Dobsonian Telescopes

Wow, lease to own is a great idea!! Don't like being in debt, so this is a good system. Wish there could be a service like this in the UK.