John Sayers' Recording Studio Design Forum Archive

Some will remember me as the guy building a studio on the 7th floor of an office building. If the soundproofing doesn't work as well as hoped, I will just do loud recordings (drums) after hours, so please don't warn me against the idea, I'm OK with it. I'm finally getting my permits to begin, with conditions that I work out an AC solution that doesn't complicate or disturb the existing plant , and secondly that I don't alter the appearance of the lobby glazed doors.

As the lobby glazed doors will be part of my external wall (for RWAR construction), they will need to have the 12mm gaps around the doors filled, and the entire door surface needs to be "beefed up" by attaching material equivalent to 12kg / m2 behind the glass to match the external walls on the other sides. These glazed doors will be blocked off and do not need to be transparent. It will be ok to have a frosted appearance, so long as at some point down the track, the reinforced material behind the glass can be removed to "make good" the original doors (for resale).

So, in order to avoid a triple leaf effect, I need a material that will attach directly on to the glass, that will not require it's own supporting frame, which would mean losing 90 - 100mm space inside the room. So my idea is to silicone 10mm acrylic glass (plexiglass?) directly to the rear of the existing 3 x 10.38mm laminated glass doors. This precludes the use of extra space consuming framing, and also avoids a 3rd lead . Furthermore, the plexiglass should be removable from the glass if need be by cutting through the silicone with some thin wire. I think it's messy, but the glass can be cleaned up (siicone scaped off?). The plexiglass may need a small border top and bottom to secure it, but should stay in place, no?

Anyway, if the plexiglass CAN attach to the glass and held in place with some silicone, I want to know if Green Glue can also be applied in between the acrylic and the glass, for some extra damping (not for adhesion). Maybe silicone around the edges, and green glue elsewhere?
If this is do-able, how easy will it be years later to remove GG from glass?

Thanks.

if you create a wall behind the glass which is more massive than the glass, you should be ok. i would laminate the glass with some opaque window covering, frosted, blacked out, silver, etc., then plan on build a wall separate from that, and damp the interior of that space with semi-rigid insulation (so if the space if 2", insert a 2" semi-rigid or compress light insulation so the outer mass and the windows are contacting it. make considers for venting that space if moisture is a problem. in this approach, the window is literally just window dressing the mas of your interior walls etc are the TL defining layers. also the laminate (like they sell for cars etc) should peel off once needed.

gullfo wrote:if you create a wall behind the glass which is more massive than the glass, you should be ok. i would laminate the glass with some opaque window covering, frosted, blacked out, silver, etc., then plan on build a wall separate from that, and damp the interior of that space with semi-rigid insulation (so if the space if 2", insert a 2" semi-rigid or compress light insulation so the outer mass and the windows are contacting it. make considers for venting that space if moisture is a problem. in this approach, the window is literally just window dressing the mas of your interior walls etc are the TL defining layers. also the laminate (like they sell for cars etc) should peel off once needed.

There will be a room within a room, so yes, there will be another wall behind a 100mm insul filled gap, and this inner wall will be 37 kg/ m2 mass, similar to what the glass/plexiglass mass will be if I glue them together. My question is about this glass /GG/Acrylic sandwich - can it work? Can I separate the glass from the acrylic if I need to, and can I get the gunk of the glass (the acrylic I'd throw away once discarded...)

no idea - you might reach out to green glue company and see if they have any experience with it. i think just a nice heavy laminate and damping the air space will be effective. if need be, just add drywall over the laminate on the glass and use some cleats to hold it in place.

princeplanet wrote:Can I separate the glass from the acrylic if I need to, and can I get the gunk of the glass (the acrylic I'd throw away once discarded...)

In theory some silicone removal liquid could work there, but I've only tried these on much smaller areas where they work amazingly well.
but you do need a lot of time and some sort of mechanical removal also.
Maybe even leave couple of steel wires/strings between glass&acrylic when gluing them?

https://www.kiilto.com/product/kiilto-s ... e-remover/
https://www.bison.net/en/product.885

but dont know would there be some other way, or some glue you could heat to remove etc?

edit: Personally I would look for other solutions or something that gives the same (or acoustically even better) results without need to glue/seperate anything to glass,
but if this is the only way then its doable..but a lot of work

i think the laminate is the way to go - opaque to hide the inner workings, then if you need to glue things to it, the laminate should be easy(er) to remove.

Hey thanks for the replies all . Here's a couple of new twists- Firstly it now appears I need to attach the acrylic to the front of the glass, not behind like I was hoping (because of available space b/n walls). I'll see if it's OK to stagger the joins of the acrylic glass to cover the gaps around the orig glazed door. As for how to attach the sheets, I read on a GG site yesterday that GG should not be used in conjunction with other glues (silicone??) because it creates a solid contact point which defeats the point of using GG (which is more about "floating"...)

Trouble is, if I only use GG, how do I stop the acrylic from moving around? Could cleats keep the acrylic in place?

...hmmm, someone on another forum mentioned that at least one mass layer needs to be porous for the GG to work. If that's true then I need to try something else, maybe sandwich MLV (I have plenty) between the glass and acrylic? Would silicone work in this configuration?

try it on a small section to see what adhesion you get between the MLC and glass using the silicone. maybe thin double side tape strips crisscrossed on the window