Is this glue acceptable for booth glass sealing?

I am following Rod's instructions for installing my windows. For the sealant in step 4 of his instructions, I found some 3M Urethane Window-Weld at Napa. It's basically used for car windshield replacement. And will make a nice air tight seal. Only thing I am unsure of is how hard the stuff is once it fully cures. You want something somewhat flexible, right?

Rod Gervais wrote:

1. First things first - you take the setting blocks and use them to shim the glass - (Yes it's only the bottom that has to be shimmed). These should be in 1/3 bearing locations for glass up to 8' - and 1/4 locations for glass over 8' in length........ and the idea is to vary the thickness of the shims to settle the glass centered in the frame. 2. Then mark the exact location of the shims - remove the glass - install the butyl tape on the 4 inside stops - reset the shims and reinstall the glass.... centered left to right - 3. press it hard against the butyl tape and install 2 temporary stops to support it at the sides towards the top- make certain it is pressed hard against the butyl tape. 4. caulk the top with your silicone lapping about an inch down the sides..(the butyl will act as a backer rod) then install the butyl tape to the top piece of outside stop and install the outside stop - being careful to make certain it is firmly locking in the glass........

Here's the PDF document on the stuff: http://multimedia.3m.com/mws/mediawebse ... _08609.pdf http://solutions.3m.com/wps/portal/3M/e ... RC9RGN5Fbl Or, would something like these be more ideal? http://www.technologylk.com/black-adcos ... B100B.html http://www.technologylk.com/crl-black-7 ... 777BL.html http://www.technologylk.com/crl-gray-88 ... 88GRY.html http://www.technologylk.com/black-pti-7 ... 707BL.html

Rod suggests butyl caulk. In the lack of butyl caulk you might go the way of butyl tape, this can be purchased and maybe the caulk as well, at either an RV parts store/a modular home store...and maybe any of the big box stores. The idea with butyl tape/caulk is that it can last in a resilient fashion for years. The windshield caulk will most likely last for years as well, but might produce a harder connection. So out side of the air tight ability, you are looking for the resilient factor which may or may not be present in this product you are looking into.

xSpace wrote:

Rod suggests butyl caulk. In the lack of butyl caulk you might go the way of butyl tape, this can be purchased and maybe the caulk as well, at either an RV parts store/a modular home store...and maybe any of the big box stores. The idea with butyl tape/caulk is that it can last in a resilient fashion for years. The windshield caulk will most likely last for years as well, but might produce a harder connection. So out side of the sir tight ability, you are looking for the resilient factor which may or may not be present in this product you are looking into.

I have the butyl tape already to stick to the stops. This is only to seal between the edges of the glass and frame once the glass is set on the blocks and pressed against the tape. Still a no go for step 4?

Rod Gervais wrote:

1. First things first - you take the setting blocks and use them to shim the glass - (Yes it's only the bottom that has to be shimmed). These should be in 1/3 bearing locations for glass up to 8' - and 1/4 locations for glass over 8' in length........ and the idea is to vary the thickness of the shims to settle the glass centered in the frame. 2. Then mark the exact location of the shims - remove the glass - install the butyl tape on the 4 inside stops - reset the shims and reinstall the glass.... centered left to right - 3. press it hard against the butyl tape and install 2 temporary stops to support it at the sides towards the top- make certain it is pressed hard against the butyl tape. 4. caulk the top with your silicone lapping about an inch down the sides..(the butyl will act as a backer rod) then install the butyl tape to the top piece of outside stop and install the outside stop - being careful to make certain it is firmly locking in the glass........

"This is only to seal between the edges of the glass and frame once the glass is set on the blocks and pressed against the tape. " No matter how you appraoch this the butyl is to suppress vibration between the hard glass and the hard stop...it is a decoupling... the caulk is to fill any void that you may have introduced due to improper installation....always something to be mindful of.

xSpace wrote:

"This is only to seal between the edges of the glass and frame once the glass is set on the blocks and pressed against the tape. " No matter how you appraoch this the butyl is to suppress vibration between the hard glass and the hard stop...it is a decoupling... the caulk is to fill any void that you may have introduced due to improper installation....always something to be mindful of.

I know! Thanks! So you think this window weld should be fine then? Wasn't sure if the caulk needed to stay flexible or not. I know from working on cars for a living, Urethane is like rubber, but it can be very hard compared to rubber. For example, racers usually replace rubber engine mounts with urethane mounts to reduce engine movement under acceleration, which works well, but engine vibration are more easier felt throughout the car; or they replace rubber suspension bushings with urethane bushings to stiff up the handling. So I'm wondering if this stuff might be to stiff?

I think butyl is cheaper to get and easier to work with...

One more question. Rod says you can use GE Silicone instead of the butyl caulk, which version of the GE would I use? This one? http://www.homedepot.com/Paint-Caulking ... ogId=10053

Any GE Silicone would be suitable, the GE 2 was made because the standard Silicone breaks down under UV Light - this is not a problem inside of buildings.........

rod gervais wrote:

Any GE Silicone would be suitable, the GE 2 was made because the standard Silicone breaks down under UV Light - this is not a problem inside of buildings.........

Sweet! Thanks a lot guys! :D