Laura, Not sure what's going on with your glass pieces. Do you have GEII for windows and doors?? Once in a while I will get two pieces that are not a smooth fit and have to pay special attention to the seal. But the if there is a smooth fit everything sets ok. Maybe some other member will chime in with some insight for you. Hope you get your problem fixed.

Kat

I sometime have that problem if I have to put it on to thick to fill in some grooves, it needs air to dry properly but it will dry eventually.

I have that problem, too. It's like a guessing game- will it or will it not work today?

So I started pushing down on the piece, not hard enough to break it, but making sure that the seal is tight. Sometimes I even hear a little 'pop' so I know all the air is pushed out.

I've also learned that the lip of a piece needs to have a thicker edge to bond well. The ones that are real thin, don't work.

I have to say I too have had that problem.
I try to get glass that has a nice flat surface and large lip.
I have had to use thinset on occasion. When I mix it I add weldbond to it instead of water and that holds really well.
I know some don't like it for outdoors, and I haven't had any problems with it, but I don't have extreme temps here.

I'm glad I'm not the only one with this problem. Yes, kati, I do use the GEII for windows and doors.
I think the thicker lip theory is correct. Some of the pieces I've had trouble with had a thin lip. Also, I've had a problem with bonding to a bottle top. Almost never seems to work. Maybe I'll try the thinset/weldbond formula. Also, I was told that that Nova glass has a product that works on small surfaces.

Hi! I work w/ glass & 1 thing that helps adhesion is to roughen the contact surfaces w/ sandpaper or a grinder/ grinding wheel, sanding block, etc. Enough so that you wipe away debris & see a dull area like it's etched. Even etching cream can be used to improve bonding!
Also, glass must be really extra clean--we recommend Windex followed by alcohol. Then I use clear packing tape to stabilize it for several days, being careful not to get silicon smeared between the tape & glass. The tape is good; leaves no residue!
Hope this helps!

I have began roughing up the surfaces sometimes also. I think I need to do that more often. The latest one I had so much trouble with was a round ball type jar cap (glass)that I glued inside the top of a small bowl. I think the rounded part was the main problem. I used some marine epoxy around the seam to stabilize it when I glued with silicone the second and it still wasn't totally solid, then covered that with 1/2 round marbles the color of the glass. It was a custom order from a woman I met at a party a couple of weeks ago. She picked it up today and I didn't get a photo first. Can you believe that!! I going to call her and ask to come to her house to take a picture.
I also wash the glass thoroughly and clean with alcohol.

As silly as this is going to sound, when I used to make glass sculptures with framing glass I broke when I was framing pictures, was good old fashion Elmer's glue. Tape the pieces you are going to put together and cover the seam with Elmer's. It will dry clear in a day or so (depending on how thick you make it) then silicone over it all. The Elmer's will take it and if you have to, roughing it up is easy to do!

Hope this helps!

Silicone sealant/glue is used for structural purposes.
If you walk around city downtowns, you will find high-rise buildings glue their window glass to the building structures. This obviously subjects the glue to very high wind and exterior stress conditions.

Silicone glue is rated at about 350 lbs per sq. in. strength.

The problems you have mostly are in the quality of the glue that you are using and improper applications.

dcarch

Thanks dcarch. Now the questions...I only use GEII silicone for windows and doors with a far out expiration date. Anything else I need to look for?
What would be examples of improper applications. I've wondered if sometimes I've used too much. If I have a problem it's with only 1 or 2 joints, not the whole structure. Also, sometimes when it comes apart, there is no adhesive showing on one piece which has led me to believe that it was too slick, too rounded or whatever. At that point I usually rough it up with sandpaper or a grinder. Any suggestions you can make will be greatly appreciated.

laurastheme ,

1. The expiration date applies only to the tube before it's open. Once it's open, the date is no longer valid. The glue will start to deteriorate once itÂs opened.

2. To apply the glue correctly, just follow directions that come with the glue. For glass, you do not need to make the surface rough, just dirt free.

3. Before you start any major project, try it out on a small area, so you donÂt waste all the time and material.

dcarch

One more thing:

This is not something I do, so I don't know. I would try this out.

I have a feeling that exterior silicone caulking (need a cheap caulking gun to use) that comes in a much larger tube may work very well for most of what you guys are doing.

You will save a lot of money.

dcarch

Sorry to hear others have had problems with this fun craft. Since I've had very few problems making totems I'll tell what I do. I've used GE Silicone II for exterior windows as well as a store brand silicone from a Canadian national hardware store which works as well altho is much cheaper - probably made in same factory as GE. I use the big tubes in a caulk gun which took a bit of getting used to but I now find it easy to use.

I *always* wash, rinse, and dry glass very well. I also seldom use glass with thin edges. Won't say never but almost never. I like the edge to be wide enough for a good 1/8"+ bead of glue. If I do use a thin edge piece it will be very near the top of the totem. With pebbled glass I use more caulking so there's a good seal. I also give a slight twist as I place the piece on and seat it securely.

One thing I feel is important is to allow each layer to dry for several hours before adding another and to not move the finished piece for a couple of days. At the most I slide the finished totem to a corner. I usually have 3 or 4 totems going at the same time because it can take me several days to make a tall one (with 12 to 16 glass pieces in it) and at least another few days before I move it outside. It's one of the reasons I'm taking a break from totem "creating" so my kitchen can have a rest from looking like a glass explosion took place. ;-)

IMO there may be another cause of failure to bond and that is that some glass that looks colored or frosted has a coating that I believe is a type of plastic. I have a few pieces of those but have not dared use them yet. Might eventually test them out in a small totem but I expect the bond won't be as good. I've washed some in the dishwasher and the coating comes off. Partially. What a mess. DH used paint remover on one so it's cleaned up. The other one I scraped with a knife. Never again will I buy such pieces. One has to look carefully to see this coating.

Hope this helps, it's very frustrating to spend time on something to have it come apart.

Thanks for all this input. I still have one question. When I glue several pieces together, why is there sometimes only one that won't bond? I'm looking at one now that is a glass round piece about 1 1/4" in diameter and has a 3/8" lip. I glued it to a mirror (which I've never had trouble with before) and it came loose after sitting unmoved for a couple of weeks. I don't think I've used any glass with the plastic coating or painted glass. If I have any doubts I scrub a little area with fingernail polish to find out if the finish comes off. And I always wash the items and clean with alcohol.
dcarch, interesting that you mentioned deterioration after opening the tube. I suspected that some time ago, so now I throw it out if the silicone begins to be quite stiff or hard to get out of the tube. I also roll up the end of the tube and clip it together as the silicone is used.
I've considered using the caulk gun with the larger tubes, but DH thinks it would be too hard for me to handle. Maybe I should try it.

TEACH that hubby a thing or 2,3,4... the caulk gun is EASY as long as you remember... when your almost to the end, I stop triggering, but ALSO click the little tab in the back to release the pressure. This stops excess flow. Because the gun/tube is bigger & we only have 2 hands, I like to have my work on a table, on a turntable, about eye level. The Rubbermaid spice jar kind. This way, I can have my hands on the gun and only need to spin 1 or 2 times even on a large surface. Gives you a nice even band of glue - less chance of missing. HTH

Hey! I had ALL my last totems fall apart!!! Grrr! Used a new glue called Industrial Gloo. Grrr! BUNK! I have one totem in my yard that has been outside for 5yrs!!! Never a problem, but all this stuff I've been using lately is bunk! I never realized that maybe there is a difference with handblown stuff....

I think I'm going to try the caulk gun. According to DH the trick is knowing when to stop triggering.

" ---I think I'm going to try the caulk gun. According to DH the trick is knowing when to stop triggering."

The key is to release the plunger, otherwise the content will still come out.

If you do a lot in the futrue, consider getting an electric powered one.

Also, there are two sizes, one is a giant contractor size.

The gun also is useful for applying "Liguid Nail" adhesive.

dcarch

If you want a good sealant for glass, do not use the hardware store acetoxy silicones. Dow Cornings CWS is a high performace silicone.... much better then Home Depot garbage. you have movement capabiltiy, very high tensile strenght and the adhesive qualities are much better then BATH Tub type silicones...

heres a link to the product http://www.sealantengineering.com/catalog/item/7123679/7255828.htm

I'm new at this but.............
Don't press the two items together too firmly ..
You want enough glue to remain between the two pieces ....
Also GE II is made to be flexible so the items may feel loose but that is just the flexibility properties that allow it to shift a bit without cracking the glass...
They now make a "NEW AND IMPROVED" GE II Sun and Freeze Proof....
I haven't tried it yet but how can I miss with "NEW AND IMPROVED" ..........LOL..