adhesivemetalplastic
I have a small plastic torch (flashlight) with a magnet on the back. I use it to provide light in a small metal trailer. Recently I pulled the torch off the metal wall, and the magnet came away from the torch.
I've fixed this problem before, but the glue I used seems to fail in cold weather. (I'm in the UK, so by "cold", probably I mean 3°C down to -5°C.) Can someone recommend some suitable glue?
J-B ClearWeld Quick Setting variety says it cures clear and sticks to metal and glass. I have never used this particular J-B product but I have had good results with other products of their line of epoxy.
The surprising (to me) answer may be ABS cement. You probably won't find this in the hardware store glue isle, instead head over to plumbing:
You'll want the smallest can possible (e.g. 4oz), and after use to seal it in a zipper lock bag and store in a cool dry location. The stuff goes bad in the can pretty fast.
The ABS cement worked for me far better than any of the other glues mentioned above. You can also cut out a small piece of ABS drain pipe, or other ABS item, to use as a patch for the repair.
Note that ABS cement is a mix of a solvent and ABS powder: in the end you really end up welding the plastic more than gluing it. For this reason clamping is recommended.
Best Answer
Some sort of 2 part epoxy should hold up pretty well. Araldite is a common brand in the UK. For best results, try to remove the old glue so the bond is to the plastic itself, scuff both surfaces with sandpaper, then clean with something like alcohol to ensure the best bond. Allow to dry before applying epoxy. It's important to use the specified proportions of resin and hardener (usually 50:50) and that the two are well mixed. The epoxy should cure at room temperature or as specified, but once fully cured it will hold up under fairly extreme temperatures. It is also waterproof and resistant to most chemicals.
Be sure it is only applied to surfaces intended or materials disposable. It usually is impossible to remove once cured except by grinding away.
Besides epoxies, polyurethane based adhesives work well also. The two part versions are stronger but the more common one part formulas work quite well too and are more convenient to use. Such adhesives can be found in sizes anywhere from small craft quantities up to large tubes of construction adhesive by the case. Note that not all construction adhesives are polyurethane based.