Long overdue mirror clean

[Saganite]

I have owned my OO12" Dob for three or four years and seen some stunning sights through it, and being the last day of the year I thought I would wash the mirror as it was looking a bit dull and had a few water marks.

I was quite shocked at just how dirty the mirror was, thick with dust , which I feel is due to keeping it in the garage where floor dust and debris gets blown about every time a door is opened. The dust cap has been on an awful lot longer than it has been off this year, and so the ingress must have been under the mirror cell and even through the cooling fan I should think. I will be keeping it inside the house in future. Much longer cool down time is the lesser of two evils, by a long way.

A lot of washing in soapy water and clean water, and a final sluice of steam distilled water  has done the trick though, and I am quite relieved.

Apart from the necessary cleaning it gave me the chance to get acquainted with the mirror cell, to adjust and set to my liking.  It was released by Orion Optics in 2015 and I discovered that it had been given a Hilux coating, something I was planning at some stage.

Reassembled and with perfect collimation , it now just needs a clear sky as early as possible in 2022.

Happy new year to all, and clear skies.

 

Edited December 31, 2021 by Saganite

[John]

Nice job Steve

 

[CFarVT]

Looks great

[JeremyS]

Excellent 👍🏻

[Saganite]

Thanks for the approval.

It should certainly perform better !

 

[discardedastro]

Looks good - I'm steeling myself to drop the cell out of my OO VX16 tomorrow and do a similar cleaning exercise! The complete absence of clear skies made me reconsider leaving it till summer - why not now?

I'm going to do a good clean as well as bolting/tapping some more bits to both the mount and tube to properly secure the Telrad and prepare for some encoders I hope to fit sometime this year. The whole thing needs a bit of a clean, some paint, and a bit more flocking.

My VX16 came with two (fabric) tube caps, which are both of Astrozap make, but I'm not a fan of these. I keep my OTA outside under a Telegizmos 365 cover, so something which is weather-permeable isn't ideal and I've had condensation drip from the inside of the TG cover onto the tube cap and from there onto the back of the secondary where it's caused a lot of rusting on the secondary adjustment knobs - this can't be doing anything else any good, either!

I'm planning to drop the primary and secondary out, replace the knobs+screw on the secondary spider and treat it all with ACF50, and refit - but am considering making a lightweight plywood tube cover. I'm replacing the tube edging with some rubber-and-steel stuff because the provided plastic is cracked and broken, so I think a simple bit of thin waterproof ply to cover the end with some locating dowels to hold it in place should do a lot better than the fabric.

I'd definitely cover the bottom end with a fabric cap at least to keep dust out if it's kept somewhere reasonably dusty. I'm doing all my cleaning on an unsealed concrete floor, which makes for more of a challenge!