Cleaning the Mirrors...

Both the Primary and Secondary mirrors on the telescope were not in the best of shape.

The telescope tube was stored in an outside metal shed for several years and even though I thought the tube openings were closed off both spiders and roaches found their way to the inside of the telescope! Seems both of these bugs have no problems finding ways into perfectly sealed enclosures.

The spiders had a field day creating all sorts of webs across the primary mirror surface and the secondary mirror was a great place for them to attach their webs - too bad for them other bugs did not find their way into the telescope tube so the spiders simply starved to death - too bad!

The roaches, on the other hand made a bigger mess - they too did not find much in the way of food so promptly just died on the primary mirror surface. Of course, since the telescope tube was stored in the vertical position as there are rubber feet on the primary mirror back-plate at the end of the telescope tube put there for just this purpose, the roaches had not problem staying on the primary mirror surface after they died. This is where they decomposed!

As you can imagine - there was a pretty good "mess" on the primary mirror surface. Thankfully, about nine (9) years ago, I had the primary and secondary mirror surfaces re-surfaced by a local shop (http://www.spectrum-coatings.com) who did an excellent job of putting a new enhanced aluminum surface coat and a silicon dioxide (Quartz) surface coat on the mirrors! This re-coating actually protected the surface of the mirrors since the quartz coating acted to protect the enhanced aluminum surface coat and I only had to do a cleaning on the mirrors to restore them to a clean condition.

NOTE: If you need mirrors re-coated I would HIGHLY recommend Spectrum Coatings for the task! They have developed a very good method of recoating mirrors and the added step of depositing a quartz coating on top of the enhanced aluminum coating really does an excellent job of protecting the reflective surface with very very little loss in efficiency or reflection! Check out their site as they have some information and test data on the process they use! They can handle Primary mirrors up to 32-inches in size and their coating technique is the best in the business, and their prices are very very reasonable too! Tell Paul I sent ya - it won't get me anything but I am sure Paul would like to know where you found out (grin).

The technique I used to clean the mirrors was really very simple. There are a good number of ways to clean telescope mirrors but the technique I use is a little different from most. I use a combination of Windex (yep - good ole fashion window cleaner) and HDTV Screen cleaner. The only place I have found (to date) for the cleaning spray is in a Kit for HDTVs -Buy.com carries the kit (http://www.buy.com/prod/belkin-hdtv-essentials-kit-includes-hdmi-cable-surge-protector/q/loc/111/204871868.html) but it contains not only the cleaning spray but also an HDMI cable, surge protection power strip along with the cleaning cloth that comes with the cleaner. I have not located a place to just get the cleaning spray and cloth but since I do have an HDTV it was not an issue for me (grin). Be sure to get the cleaning cloth as it is specially designed to be lintless and not scratch! Very important, especially the "not scratch" part!

First I wet the mirror surface with the Windex and let it stand for at least five (5) minutes to loosen any surface dust, dirt, lint, bugs or what-not... DO NOT rub the surface to remove anything and do not allow the Windex to dry on the surface of the mirror. Rubbing on the mirror at this point would be a great way to scratch the mirror surface from the foreign matter on the surface! Let the Windex do all the work and if there is still something sticking to the surface just apply a second coat of Windex after draining off the first coat.

I usually drain the Windex off the surface and wet the surface again with Windex to make sure most all of the foreign surface contamination has been cleaned off the surface of the mirror.

After the second cleaning I drain off the Windex then wash the surface off with water (best to use distilled so as not to add any dissolved contaminates to the surface of the mirror). After this step I use the HDTV screen cleaner with the lintless cloth to VERY LIGHTLY clean the mirror surface - this step should be performed with care so as not to scratch the mirror surface.

Once I am happy with the screen cleaner step I wash the mirror off with distilled water (again) then use 99% Isopropol alcohol (available at hardware stores as lacquer thinner, I believe) to rinse the mirror surface (this removes any water film left) and drain the alcohol off one end of the mirror - you can remove any droplets left with a SOFT lintless cloth - blot, do not rub!!!

Performing the above cleaning on the Primary and Secondary mirrors of the telescope restored the mirrors back to a VERY clean state - that is a GOOD THING (tm) for the purposes of obtaining the best possible images through the telescope.

Of course all of the above steps required removing the mirrors from the telescope tube - and completely destroys any previous alignment of the telescope's optics. The next step will be to install the mirrors back into the telescope tube then perform an optical alignment of the mirrors.

First - I have to make a collamating tool to use during the alignment process - one tool I need to make and the other was ordered on the Internet ...

More to follow...

gm...

Dragging out the 13" Dob.

Well - the subject of this blog is "Telescope Fun" and that pretty well describes what I am enbarking on here. I have a Coulter Optics 13.1-inch (33.27 cm) diameter Odyssey 1 Dobsonian Reflecting Telescope I had purchased in 1986. Coulter Optical no longer produces this telescope nor the primary mirror - the largest they have listed on their website (http://www.e-scopes.cc/) is a 12-inch primary mirror and secondary for around $600.00 (just the mirrors) I purchased the 'scope to view different objects in space along with watching the comet fragments collide with Jupiter in 1994 (and it could be seen through this 'scope as it was big enough to catch the action!). These telescopes were the largest you could purchase for a very inexpensive price (I paid around $700 for mine) and still have some excellent views of the night sky. Given the size of the telescope it is no wonder they are called "light-buckets".

Here is an image of what the telescope looks like - some people actually thought I had a cannon in my garage! (grin).

The telescope was stored away for some years due to infrequent use and the need for the space within the garage for other projects. It was "weatherized" and stored away in an outside shed (metal shed on raised floor) but in Florida that is not saying all that much! Sometimes the temperatures within the shed would reach over 120-deg. F or as cold as around freezing (depending on the time of year of course) and since Florida in not known for low humidity you can guess what that could be like!

All in all the telescope faired out pretty well give the environment it was stored in. The optics (primary and secondary mirrors) were covered in a layer of dust, bugs and only God knows what else so a good cleaning was in order to determine the actual shape of the mirror. Luckily I had stored all of the primary objective eye-pieces inside my air conditioned home so they faired a great deal better than the telescope (hind-sight being what it is I should have stored the whole telescope inside, dumb me!).

My next entry will be on the disassymbly and cleaning of the telescope optics - stay tuned!