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Secondary mirror attachment to it's holder

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#1 cvnori

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Posted 13 September 2019 - 06:11 PM

I recently got both mirrors of my Orion Astrograph re-aluminuzed using Spectrum Coatings. I did not realize that the secondary mirror would be removed from it's holder for the polishing operation. I would like to know of any double sided tapes that are readily available in the stores that anyone has used successfully. What I mean is:
1. The tape holds in cold climates down to -10F
2. The tape holds in hot climates upto 95F
3. The tape remains flexible and not distort the mirror,and
4. Any other extra securing methods so that the secondary does not fall on to the primary.

I also found this 3M tape:
3M Scotch Extreme Mounting Tape, 1 by 60-Inch, Black https://www.amazon.c...i_G2bFDbA9CG233

But not sure if it will work. Can anyone experienced with this tape comment or recommend others?

Thanks

#2 Sky Muse

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Posted 13 September 2019 - 06:44 PM

http://www.deepskywa...-secondary.html

 

I used silicone for my own...

 

https://www.amazon.c...68418093&sr=8-2

 

silicone.jpg

 

Before(left) and after(right)...

 

mirror-stalk position5.jpg


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#3 Asbytec

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Posted 13 September 2019 - 07:13 PM

Here's at least one CN member that might argue against using tape and using silicone instead. I use silicone. Three small dabs will do ya. 

 

https://www.cloudyni...-mounting-woes/


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#4 lphilpot

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Posted 13 September 2019 - 09:31 PM

I really wish more scopes used the older style "can" mounts - A cylindrical, typically aluminum, can with a interior lip around the 45 degree end. The mirror rests against the lip with light pressure from behind, usually batting of some sort. It makes it much easier to take the mirror out for cleaning, a heater can be directly attached to it, etc.


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#5 cvnori

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Posted 14 September 2019 - 11:26 AM

Thank you very much and I really appreciate the links and all the information in it.  Best.



#6 Sky Muse

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Posted 14 September 2019 - 09:24 PM

I really wish more scopes used the older style "can" mounts - A cylindrical, typically aluminum, can with a interior lip around the 45 degree end. The mirror rests against the lip with light pressure from behind, usually batting of some sort. It makes it much easier to take the mirror out for cleaning, a heater can be directly attached to it, etc.

My Parks Optical 8" f/5 came with one of those, and no doubt unchanged since the 1950s...

 

secondary assy4b.jpg



#7 Sky Muse

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Posted 14 September 2019 - 09:34 PM

Thank you very much and I really appreciate the links and all the information in it.  Best.

If you do decide on silicone, which is best, get the GE "Iron Grip".  I used the more-common GE exterior-type sealant, but it's for a 100mm f/4, and good enough.  Also, that's good advice in placing small amounts in a triad, yet somewhat thicker than the thickness of the spacing, that with toothpicks or wooden match-sticks, and so for the adhesive to spread out only slightly when pressed together.  




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