Sunday, September 5, 2010
Testing Adhesives for the Installation
I had saved a number of broken dragonfly pieces to do some testing of the adhesive. I had read some good reviews on a fastsetting 3M marine adhesive/sealant 5200 and decided to try adhering a few pieces to a sheet of the aluminum that was used for the templates to support the dragonflies on the metal t-bars.
The adhesive was so thick it would not come out of the tube/cartridge in the caulk gun (and two other people tried it as well) so I had to cut open the cartridge to use it. The adhesive is more like a paste and I applied it thickly to all the pieces of glass but one. Within about 15 hours, the glass was not movable. Even though it was a fast setting adhesive, it did not become warm to the touch. After 36 hours, I attempted to pound the glass pieces with a hammer on the top and sides (about a dozen times) and none of the glass broke into sections and it only chipped slightly when I hit it on top. So the adhesive provided a good cushion for the glass. The smaller piece of glass that I applied the adhesive to (photo above) more lightly did not adhere well but I used a very light coat.
The bond was very secure but I do wish the adhesive came in a clear color. It is also very messy and gets on everything so if we decide to go with this adhesive, it will need to be applied directly to the metal plate supports since they are a bit smaller than the glass. The adhesive also allows for expansion when the glass heats up in the sun.