· Get a Cloudy Nights T-Shirt · Submit a Review / Article    Click here if you are having trouble logging into the forums Cloudy Nights - Official Forums of the 2009 International Year of Astronomy Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User   You are not logged in. [Login] Forum Archives · Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Equipment Discussions >> ATM, Optics and DIY Forum Previous   Index   Next   Flat   Steven Aggas sage Reged: 04/15/08 Posts: 463 Loc: Arizona RTV, Glass, and Holder Material       07/02/09 04:20 PM Edit   Reply   Quote   Quick Reply:   Ok, there's alot of secondary holders making use of RTV to adhere the glass secondary to a stationary position on the holder.... Some holders are wood, others PVC, and still others are metal (mostly likely aluminum). Who's done stress analysis, with regard to the affects on the frontside accuracy, of the expansion/contraction of the various holder materials that contact the glass secondary which is constrained by the RTV? Secondly, is the holder typically pressed into a bead of RTV, or, is it more typical to lay a series of beads on the ID and OD of the holder against the glass? (In the first scenario an RTV film resides between the holder and glass whereas in the second the holder material is in direct contact with the glass.) Steven -------------------- Mr. Wizard Walking on a Dob: http://darkskyobserving.com/MtGraham.html Elements in Harmony I, an 8"f6 German Equatorial - Stellafane Winner, II a 20"f4.2 Newt-Dob - Astrofest Winner, III a 6"f3.5 Finder/Newt-Dob, and IV a 36"f4.5 Newt-Dob - "If it's up there, it's in here." Apache-Sitgreaves Center for Astrophysics www.DarkSkyObserving.com Post Extras       Entire thread Subject Posted by Posted on RTV, Glass, and Holder Material Steven Aggas 07/02/09 04:20 PM Re: RTV, Glass, and Holder Material mark cowan   07/02/09 08:33 PM Re: RTV, Glass, and Holder Material Biff   07/09/09 03:03 PM Re: RTV, Glass, and Holder Material Mark Harry   07/03/09 07:18 AM Re: RTV, Glass, and Holder Material PrestonE   07/03/09 03:36 PM Re: RTV, Glass, and Holder Material mark cowan   07/04/09 02:42 AM Re: RTV, Glass, and Holder Material PrestonE   07/04/09 04:12 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/06/09 03:18 PM Re: RTV, Glass, and Holder Material PrestonE   07/06/09 08:55 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/07/09 12:25 PM Re: RTV, Glass, and Holder Material PrestonE   07/07/09 04:11 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/07/09 05:34 PM Re: RTV, Glass, and Holder Material mark cowan   07/07/09 09:10 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/08/09 12:39 PM Re: RTV, Glass, and Holder Material PrestonE   07/10/09 02:43 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/10/09 03:33 PM Re: RTV, Glass, and Holder Material PrestonE   07/11/09 11:12 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/13/09 12:14 PM Re: RTV, Glass, and Holder Material PrestonE   07/15/09 05:50 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/16/09 11:28 AM Re: RTV, Glass, and Holder Material PrestonE   07/17/09 10:37 AM Re: RTV, Glass, and Holder Material Steven Aggas   07/13/09 12:16 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/13/09 05:06 PM Re: RTV, Glass, and Holder Material mark cowan   07/08/09 03:42 PM Re: RTV, Glass, and Holder Material Steven Aggas   07/09/09 12:28 PM Re: RTV, Glass, and Holder Material Charl   07/06/09 06:43 PM Re: RTV, Glass, and Holder Material PrestonE   07/02/09 06:13 PM Extra information 7 registered and 7 anonymous users are browsing this forum. 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