How I spent my afternoon...

[Andrew*]

Another tube flock and mirror wash thread.

mirror before.

(click to enlarge)

the wash:

- remove mirror from cell.

- wash out baby bath

- put mirror in baby bath

- shower mirror gently with luke warm water

- soak for half hour or so

- rinse again with shower

- rinse with de-ionised water

- stand upright and pick off water droplets with corner of tissue

- put mirror back in cell :shock: this was really tricky on my own, but somehow I managed without incident

mirror after. A bit disappointed that the sticky stuff didn't go, and it was still pretty dusty. I decided not to bother doing it again as it probably wouldn't affect views

(click to enlarge)

tube after. Eli (partner) and I did the whole tube at once - great team work, and the result was very smooth and dark indeed

(click to enlarge)

I did the spider and secondary too. I know this will make the spider a little fatter, but... something (and yes, I have angled the secondary correctly now)

(click to enlarge)

and the final result. I think I'm still going to do the inside of that rim at the top of the scope. It's very reflective...

(click to enlarge)

I'm really getting a personal attachment to this telescope. Please don't ever let me sell it... My next job is to spray it a better colour. I'm getting sick of the logo and optical information on the tube, and there are some nasty scratches too. What colour would you choose?

Cheers

Andrew

[Paxo]

Look like you've done a flocking good job there Andrew. Will you be bringing this scope to Kielder in a couple of weeks, if so I might get some tips from you.

Steve..

[Andrew*]

Thanks Steve

I guess I will bring it. If you wish, I can describe in detail the method I used on here...?

Just before anyone says it - the before and after pics of the mirror aren't as drastic as they look. The before was taken at a more "flattering" angle, thereby showing less of the marks, and the after was taken to show the maximum possible marks. The improvement of the wash was in fact very good, and when looking at the mirror head on (as you would usually, of course) there is very little defect to be seen.

Andrew

[knightware2]

Tube color is a fun question. If the scope will sit out in the sun before observing, keep it light in color, but you might want the area around the focuser to be black to keep reflected light into your eye at a minimum.

The tube of my 8" reflector is white except the top 12 inches or so which is painted flat black. The white is easier to see at night so that no one runs into the scope, and the black around the focuser really makes a difference. My daughter once asked me to paint it all red but I was leaning towards lavender

Your flocking looks really effective. I wonder what the diffraction pattern looks like given the flocking on your secondary. I don't think I've ever seen that before.

- Phyllis

[ncjunk]

Would it make a difference if you used an alcohol based

cleaning fluid as the last step in the process. I bought

some cleaning fluid and wipes for the CCD sensor of

my camera and they work really well or is it too risky

on the scratch front.

Neil C

[Andrew*]

Phyllis,

I had never considered tube colour from a practical point of view, actually. How about Friesian cow pattern with a particularly large black spot around the focuser

Your flocking looks really effective. I wonder what the diffraction pattern looks like given the flocking on your secondary. I don't think I've ever seen that before.

Thanks. I'll try to get a pic of the diffraction pattern at the next opportunity. In hindsight the spider flocking was probably quite pointless, although I do imagine that it will tackle stray light coming into the top of the tube at an angle (e.g. planes, torches etc.).

Would it make a difference if you used an alcohol based

cleaning fluid as the last step in the process.

I didn't want to use any cleaning agents for the cleaning. I've heard people use a drop of washing-up liquid, and indeed probably should have done this. I've also heard tell of folk using IPA, but I don't think this would be very kind to the coatings...

I bought

some cleaning fluid and wipes for the CCD sensor of

my camera and they work really well or is it too risky

on the scratch front.

I think so. The idea about cleaning mirrors is not to make any contact with it. For stubborn marks, the weight of a wet cotton bud is acceptable on the surface, but no more.

Andrew

[Xunil]

I had never considered tube colour from a practical point of view, actually. How about Friesian cow pattern with a particularly large black spot around the focuser

Actually, if that idea isn't used here then I'm stealing it

[John]

Thanks. I'll try to get a pic of the diffraction pattern at the next opportunity. In hindsight the spider flocking was probably quite pointless, although I do imagine that it will tackle stray light coming into the top of the tube at an angle (e.g. planes, torches etc.).

You have done a good job on cleaning the mirror and flocking the tube but I did wonder about the flat and spider as well Andrew

I guess the effective size of the secondary will only be a fraction more with the flocking. I will be interested to see if flocking the spider increases the prominence of diffraction spikes - the original vanes were .5 mm thick - I reckon the flocking material on both sides adds about 2mm to that - but it may not make a difference of course to the actual views that you get.

John