Question about setting glass in window

Started by SonicClang on 8 February 2006. 5 replies.

Originally posted at johnlsayers.com, topic 5594.

My question pertains to how the glass actually sits on the sill. If you angle the glass, won't it sit on the corner of the pane? If you've got argon-filled glass, could that damage the seal in any way over time? Or can you make the edge of the glass angled to match the angle of the glass?
Ok... that link isn't really what I was talking about. I know all about the blocks you put in the window to keep the glass in, that wasn't my question. But the reason that picture isn't what I was talking about is because the peices of glass aren't shown at an angle... and I know the "to angle or not to angle" discussion is as old as time itself, but I've decided I'm going to angle my glass. Right here the guy says "Don't worry about angling the glass except for redirection of early reflections at the mix position; flutter echo off the glass will likely be solved by rear absorption in a small room anyway. Only other reason to splay the glasses is visual glare, which can be controlled with lighting position - " So his descriptions and diagrams are great if you're making your glass horizontal. And I totally disagree that you can control the visual reflections with different lighting positions. I've got some of the most customizable lights in my control room that I've ever seen. I have infinite possibilities for lighting, and over about a 1 year time frame, I could never eliminate the hall of mirrors effect of having the glass horizontal. That's when I switched the temporary plexy glass to angled. All my visual reflection problems went away. Before anyone flames at me about that decision, I offer some solid reasons. First is this:
External image, not preserved — original: http://www.saecollege.de/reference_material/images/Windows.gif
My other reason is I have experience with angling or not angling the glass. How so you may ask? I've had temporary plexy glass in my CR window for the last 2 years, and I've tried having both sides horizontal like Auralex suggests, and I've tried having them both angled like SAE suggests. With them both horizontal you see about 4 reflections of yourself before you see into the live room. And if the lights are off in the live room you can hardly see out at all, it might as well be one way glass. But when I angle both sides of the glass, well then it's great. Only at just the right angle can you see even one reflection, but best of all, you're taking the hall of mirrors effect right out of there. If you do see a reflection, you only see one, not 4. Having said that, in the picture I just posted from SAE, they show the glass as a 2 pixel wide line. Well, my glass isn't going to be 2 pixels wide, it's going to be 5/8" and 1" thick argon-filled. Take something that's 1" wide and set it on the same angle the glass is in the SAE picture. You'll see that the glass itself is sitting up on its own corner. My question is, is that bad for the glass? (simple question I know, but I have to make sure everyone understands what I'm asking so they don't post links to the wrong things assumming I'm just some noob). I've been building my studio for almost 6 years now, so I've thought all of this through a lot... except the "glass sitting on its own corner" thing.
It will not make any difference because the rubber seals that actually stop the sound will be higher up the glass anyway - but you can get the edges of the glass cut on an angle if you really want to it will just cost you alot more. I just sat the glass on glass blocks on its leading "edge" like you describe, squirted siliccone into the gaps and then installted the beads and seals. Easy as. It will not be "bad" for the glass if it's sitting on its own corners JG
It has been shown that angling your glass will not improve your isolation. It is much better to leave them parallel and maximize the distance between the two panes. Use a thickness that equals the same weight as your wall construction per sq ft. With the angled glass, the narrowest dimension becomes the weakest link in the structure. However, angling of the glass can help the inner acoustics when the pane poses a reflection problem in the control room. -ashley
Its pretty hard to look through two parallel panes. It requires very directional lighting in the room you are looking into.