Like Ezy, I was also concerned about the amount of dust buildup on my primary mirror. Despite having plastic caps fitted over both ends of the scope 99% of the time (12" dob), the mirror still seamed to have an accumulation of crud-dust that I thought must have some impact on my viewing.
(Maybe this is more applicable to dob owners simpy due to the increased size of the equipment beng able to accumulate more crud.)
Maybe its not such a big deal so I chose to ignore it.
Procrastination set in as to do I don't I and what if I stuff up the........ or scratch the ...., anyhow, seeing as I am on holidays, I thought lets give it a go. Read the threads on IIS and decided to give it a go.
By the way I have had my scope and have never collminated it. Bought a cheshire and found after 14 months still to be pretty well collminated. Boy I give this scope a working. Up steps on a trolly and down steps on a trolly, left outside most nights (under cover, but still exposed to the elements). Definately no complaint about the views previously, only the what if's.
Anyhow, decided I must check the optics and if required clean the primary and secondary mirrors.
I was amazed at the buildup of dust-crud that can accumulate on the mirrors, particularly the primary. I have a faithfull observing companion, buddy the labrador and I was amazed at how many of his hairs had accumulated on the primary. (Looking in from the end of the scope I never noticed this).
So, following the steps that Ezy has detailed (and are available on a thread somewhere on IIS) AND, as well as fully removing the primary mirror I gave it a go.
The hardest part of the exercise was to collminate the mirrors once fully re-assembled. (is really simple once you get the hang of it).
Perhaps I should have done this sooner as I always anticipated that as I move along in this hobby, I would get better at viewing and what I was viewing is as good as it gets. Maybe I was putting poor viewing down to selection of eyepieces, or poor viewing conditions, (or maybe even worse failing eyesight, I am getting older).
The viewing is so much more crystal clear that I have noticed before and sharper. i have only had a couple of nights to compare over what I have previously viewed, but is definate improvement.
Point is. Was a simple exercise really, to both clean the optics and collminate. It was worth the exercise and in my opinion so far has been justified in my increased sharpness and clearness of viewing.
It was a matter of following thew steps as highlighted in the various threads.
Nothing went wrong, only increased satisfaction of viewing.
Thanks to the guys that posted the threads on cleaning-collminating your optics.
Ken M
They have a ripper new deal on 8" Dobs with mirror fan + 2" Crayford. 
L.
