Clear Urethane Glue
Works on almost any porous surface
I bought a 2 oz. bottle of this glue 4 or 5 years ago, and the bottle hasn’t dried up yet. The glue works on a large array of different materials. I’ve recently used it to glue chair spreaders back in, to attach a strong magnet* to my 25-foot tape measure, and lots else. I don’t remember it failing to hold anything I used it on. It dries fairly quickly, and clear, and doesn’t swell up or foam like some other urethane glues. It’s thicker than water, but not as thick as silicone caulk. It will run if put on a vertical surface. It’s thick enough that I store it spout-down in a jar, so I don’t have to wait for it to flow from the bottom. The glue peels off of the plastic cap easily. It’s fairly pricey, but I like it enough that I just bought a 4 oz. bottle for when the small one runs out. Also available at craft stores.
* (A great source of strong magnets is old hard-disc drives. You shouldn’t leave a HDD in a computer you’re disposing of, and if you can get the drive apart, there are a couple of very strong magnets bonded to metal plates inside. The discs make good signaling mirrors, but weigh more than a CD.)11/7/17