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- To: owner-atm@shore.net
- Subject: BOUNCE atm@shore.net: Non-member submission from [Aart Olsen <aart@ux1.cso.uiuc.edu>]
- From: owner-atm@shore.net
- Date: Sat, 22 Feb 1997 09:19:29 -0500 (EST)
>From atm-owner Sat Feb 22 09:19:23 1997 Received: from shore.shore.net (root@shore.shore.net [192.233.85.136]) by relay1.shore.net (8.8.3/8.8.3) with ESMTP id JAA23884 for <atm@relay1.shore.net>; Sat, 22 Feb 1997 09:19:23 -0500 (EST) Received: from ux1.cso.uiuc.edu (aart@ux1.cso.uiuc.edu [128.174.5.59]) by shore.shore.net (8.8.3/8.8.2) with ESMTP id JAA10349 for <atm@shore.net>; Sat, 22 Feb 1997 09:19:21 -0500 (EST) Received: (from aart@localhost) by ux1.cso.uiuc.edu (8.8.5/8.8.5) id IAA15364; Sat, 22 Feb 1997 08:19:20 -0600 (CST) Date: Sat, 22 Feb 1997 08:19:20 -0600 (CST) From: Aart Olsen <aart@ux1.cso.uiuc.edu> To: atm@shore.net Subject: Re: ATM Concrete epoxy-liquid mirror In-Reply-To: <m0vy1eN-00060fC@freenet.durham.org> Message-ID: <Pine.HPP.3.91.970221214443.12089B-100000@ux1.cso.uiuc.edu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Ric: I thought all gloss epoxy would necessarily be liquid and therefore would have to be spin cast (and how do you get a smooth gloss finish on a floor with a trowel?). But if the epoxy is very viscous it might be better for what I have in mind anyway: Not to dissuade the enthusiasts here, but I don't expect to get a finished optical surface by spincasting epoxy. What I had in mind was to mold a shaped blank: a concrete substrate overlaid with a very thin epoxy layer which would be polished and figured against a pitch lap as if it were glass. If a convex glass tool already close to the final figure is available then it makes sense to mold this epoxy layer with the tool, and a viscous epoxy might be advantageous. If an accurate mold is not available -- e.g. you're making a new size and F.L. mirror -- then spin casting a more liquid epoxy sounds attractive, but only to arrive at a fine-grit stage. I'll play with this over the weekend. I have a 10 inch convex glass tool that can be the mold for a 10 by 2 inch concrete substate. Next weekend I'll use the same glass tool to mold a couple-millimeter epoxy layer over the concrete. After that cures we'll see how it goes -- I have no idea how epoxy polishes. Aart M. Olsen mailto:aart@uiuc.edu 217-244-4688 Library Systems Office Univ of Illinois at Urbana-Champaign On Fri, 21 Feb 1997, ric rokosz wrote: > The epoxy mix suggested at http://www.owlnet.com/epoxy/5.html is a dense > material that you trowel onto the concete.Works great I guess,but not a > fluid in any sense of the word,so spinning it would be a challenge. > -- > Ric > >
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