Glazing Question

[glassygal]

Case : I have a pair of 46 by 9 inch sidelights to install. These are leaded bevel clusters . The client has one long clear bevel in exisiting sidelight now. They want me to install these panels behind this existing bevel. I was going to put foam window tape between the two panels and have a carpenter put new molding on the inside window frame to hold new leaded panel in window. I talked to CR Lawrence and they suggested using the dessicant glazing tape and then sandwiching the bevel glass and the leaded panel together and caulking around the outside edge and install this as one unit. My concern with this is the moisture that could come from the leaded panel from putty.How could you repair if issues happened down the road? Would this cause condensation or if the fumes could cause and issue . I plan to have panel dry for at least four days before installing.I figure the first idea is best. That way if moisture happens the panel can be taken apart by removing molding and be cleaned and re install. This window faces the South and is in Cleveland Ohio . Help- thanks for all that reply.

[mmezalick]

First off, most of the glass industry indicated the measurements of a glass panel by width x height. I will assume that since you said they were side lights the measurements are 9? x 46?. I try to ?see? what people are describing when responding to questions.
Anyway, if the new panel is a beveled piece, I?m not too sure I would worry about broken pieces. You would need to remove the panel to fix them anyway. That is easy with just a bit of prying and a bent knife, much like they sell at C.R.lawrence for removing windshields of cars. Here is a suggestion that many answer your questions. Put small pieces of the tape along the perimeter; say a 1? piece every 6?. Then make sure the top and bottom of the new panel are not touching the existing frame. A small piece of wood or lead or plastic or anything solid, blocking the window up would do. Add the additional molding as you mentioned but make a few small notches in the top and bottom molding so that you can create an air flow between the two panels. Just an idea.
Michael Mezalick
Mezalick Design Studio, LLC
www.mezalick.com

[Ambrosia]

Mike is right! Keep the new beveled art glass panel elevated from the bottom and top. This will allow for proper atmospheric exchange during the temperature differential of the interior and exterior temps. Use industry standard setting blocks such as C.R.Laurence catalog #PSB250. These units are available in various heights. These units along with others available in the catalog will not compress or fail under UV exposure such as other untraditional materials as you may have seen during a local repair of an older existing unit installed by your competitor. The included diagram will help a project such as this last longer with little to no future maintenance. This type of application never has guarantees against possible condensation issues. By using EdgeTech's SuperSpacer glazing materials as CRL suggested will lead to certain condensation issues due to two main factors. SuperSpacer is an excellent product as rated by lab reports in the latest issue of Window & Door magazine. It should only be used in a triple insulated window unit application when working with art glass or traditional IG units. Your cost will also increase due to the purchase of the additional raw materials, labor and setup. The glazed beveled unit is not a true hermetically sound pane and therefore will not let the moisture back out quickly once it gets in, making the need for breathability very necessary. It will also be very difficult and costly to repair or perform maintenace if it is damaged in the future due to the fact that the newly installed art glass panel is stuck to the existing permanent window glass with double sided adhesive tapes. In our experience we have seen moisture enter this type of application from a number of means; Children and wet hands (spittle), Dog spittle and wet paws, Inexperienced window cleaners and house cleaning personnel. Try backing the panel with a protective sheet of clear tempered or pulling the original pane of glass and fabricating a triple insulated glass unit. We cement every one of our windows except triple glazed insulated panels. There are many stories through the years I could rant about but I will leave it at that.

Follow the link to the detailed downloadable pdf file.
http://www.ambrosiaglassworks.com/ambrosia/clients/forum/installation_instruction_for_beveled_glass_panel.pdf

• Ensure the existing exterior window pane is properly sealed and wont allow for moisture leakage in the future.
• Install a wood spacer of 1/4"-1/2" wide around the entire perimeter of the existing window pane. Do not seal the new beveled art glass panel to this spacer.
• Set the new beveled art glass panel into the opening using setting blocks on the bottom of the panel. Setting blocks are 2" in length and when spaced out appropriately they will allow for space for airflow to travel during atmospheric exchange. Setting blocks may be used on the sides as gapping shims. Use a dab of sealent to attach to spacer.
• Shore up the new decorative stained glass privacy window unit using appropriatly sized decorative wood or metal stops. Remember, do not seal the stops (moulding) to the window unit. This is the breathing gap used for air flow exchange.
• By leaving heavy solder beads at the joints where the came meets the border material (zinc) will allow for a ~+/- 1/6" gap between the spacer and stop materials.
• No unsightly holes need to be cut or drilled in anything, leaving the client very excited about your clean professionalism.

Ambrosia Glassworks
http://www.ambrosiaglassworks.com

[mmezalick]

Big mistake in not puttying the window. If you are making, as some call them, landfill windows than your OK. But for windows that are expected to last 100 years or so putty is like the mortar between the bricks of a wall. Without the putty the glass shifts and the strength is compromised.

Michael
PS Landfill windows are those that are meant to have a short lifetime and then they end up in the landfill.
My thanks to the person who coined that phrase.

[Vic Rothman]

Big mistake in not puttying the window. If you are making, as some call them, landfill windows than your OK. But for windows that are expected to last 100 years or so putty is like the mortar between the bricks of a wall. Without the putty the glass shifts and the strength is compromised.

Michael
PS Landfill windows are those that are meant to have a short lifetime and then they end up in the landfill.
My thanks to the person who coined that phrase.

you are welcome

[Tod]

Olympia:
Very nice work and a great website, too. You're certainly no hack!

As for the topic at hand, I cement every leaded panel I make. It seems a small price to pay for what I believe is a better result. I certainly understand your point about ventialtion in specific situations although I probably wouldn't take the same path.

Best - Tod

[Ambrosia]

I read the previous posts thinking, " Who said not to cement? ".

It's amazing how a couple of missing words can impact an entire post. There were many assumptions which we all know can come back and bite the assumer as it did. 

On behalf of Ambrosia Glassworks and over 120 days later I apologize for the potentially misleading recommendations.

We DO cement every one of the windows which pass through our doors except for triple glazed insulated panels. The appropriate verbiage has been included into the original post as to not mislead other readers in their quests for perfection.

• Always cement
• Allow for airflow transfer when installing a leaded glass unit up against an existing window pane
• When considering to install a new leaded glass unit up against an existing window pane using double sided adhesive tape, consider future repair complications in removing the unit with limited access to the adhesive.