I found a second hand 150mm f/8 Skywatcher, interesting because of its focal length and small secondary. It has a 1,25 inch focuser (that is not so positive) and does not weigh much.
Today I started with stripping the mirror. I followed the same route Douglas described here:
http://solarchatforum.com/viewtopic.php ... ic#p117999
Here is the original mirror:

Masking tape around the edges and poured some ferric chloride on it.

After about 10 minutes the dissolving started.

It took about 2,5 hours to dissolve all the metal. And here is, after cleaning, the now completely naked mirror:

Clouds and rain this weekend so enough time to apply a new center marker on the mirror, put everything back together and collimate.
Questions? Feel free! Thanks for reading, Bart.