just wanted to add to thistothat.com that gluehow.com is also a good site to bookmark http://www.gluehow.com/recommendation/glass/to/glass http://www.thistothat.com/cgi-bin/glue.cgi?lang=en&this=Glass&that=Glass Here is a link that might be useful: glass to glass

I was just looking for adhesive yesterday to bond wood panels....in the house without blowing my self up having a furnace on. I'm still not sure how safe I am with what was bought, they will mention flammable, but nothing is said about not being flammable. And tech sheets are for some scientist I haven't met yet. Branding doesn't help. It just adds confusion as to what the actual adhesive is meant for. There were more types than one would want to count. Glues are as interesting as paint to me. Both can have properties for use beyond their specified application. And branded for doing so allows them to increase cost of material significantly over what they would normally be used for. I remember 20 years ago seeing a crackle finish. A recipe combination of acrylic paint and hide glue. The guy at the hardware store said he had never heard of hide glue. When found, it was a couple of dollars for a quart. Now twice that for a very small bottle. Hide glue is the centuries first glue. It is now used for fine furniture inlays, old manuscripts/books/art restoration and wood musical instruments. One has to be a skilled craftsman to use this. Although still used by many woodworkers too. Not clear if it is the same formula as once was. Just a glue history lesson... Glue for the normal user can be very confusing. And due to regulations is not what we once knew. One of the things I have found is a good contractor may use the same type for an application, but their adhesives are far superior to what we are offered. If you want the best in various construction needs, even beyond adhesives, head for the contractor's options. Thank NASA for our selections and gluing a plane's tail. A positive as they have given us hundreds of every day life products than we could list here.

I use Weldbond to seal concrete and it works really well. I use one part Weldbond to five parts water. When I'm gluing glass to vertical surfaces I use a small amount of Weldbond on the piece I'm placing and I let it set up for five minutes or so before I place it. Letting it get a little tacky helps alot.

E6000 would be my glue of choice. It will glue everything to anything and it works great on terra cotta. (For future use it's also weatherproof so it's great for gluing outdoor hard-to-glue surfaces) For starters I would have glued the knob on before painting. The problem you might encounter depending on the amount of paint you used is that the knob will not be glued directly to the terra cotta but to the paint layer that you covered it with. There is a possibility after constant lifting up on the knob that the paint could peel off the terra cotta surface causing the knob to come off. The E6000 will still work but next time you might want to leave a small unpainted area where you are going to glue the knob to make sure it will be secure when dry. If you can I would try to either sand the paint down or at least rough up that area where you are going to glue the knob and touch up around it when it's dry. The E6000 is paintable.