For bonding metals is not suitable for every glue. Therefore, carefully read the supplied manual or consult the dealer upon purchase. If, for example, you must glue metal to rubber, look for adhesive that is suitable to both those materials, and not only to one of them.
Besides, the metal metalfrom different. If two raw aluminum parts to glue together is not too difficult, then the steel will have little trouble.
For gluing most metals better to buy two-component adhesive of epoxy resin, and stainless steel should choose the glue with methyl acrylate.
Uniform instructions for bonding metals no. Some better glue dot method, for some you have to squeeze out of the tube bead, and large planes there is a special glue that you need to smear a thin layer on the bonding surfaces.
But in all cases the metal before work will have to free from dirt and grease. This will significantly increase the quality of gluing and prolong its service life.
Cleaning details fine sandpaper, apply glue on them, as it is written in the instructions, secure them to each other and leave for some time for the adhesive.
Some glues hold much better if you give them the so-called "hot setting". Just put the glued parts on a baking sheet the oven and leave them for 3 hours at 90°C. But it can be done with the glue, the instructions which indicated good tolerance of high temperatures.