Joining two surfaces together using a variety of adhesives.

The creation of a joint using a filler (welding rod) of similar composition to the metal being joined, using electricity to generate an arc.

The creation of a joint using a filler of similar composition to the metal being joined gives rise to fumes from the electrode coatings, metallic oxides, any paint or surface contaminant and possibly to ozone and nitrogen oxides.

Thermoplastic materials are joined using a jet of hot air to melt and fuse the plastics material. A filler rod of the same material may be used to reinforce the joint.