There are also special grades of enamel for specific applications. For example, there is “self-bonding” type of enamel which has an additional layer of adhesive.
After a winding is made, the formed wires can be made to adhere to each other, by activating the adhesive with a solvent or warming up the assembly. With the thermal method the coil can be warmed up (depending on the type of the bonding agent), typically to around 120-220°C by: blowing hot air on the assembly, putting it in an oven, or by the “resistive method” (passing current through the coil to heat it up).
With the solvent method, the adhesive can be activated by applying (brushing, spraying or wicking) a suitable solvent such as denatured alcohol (ethanol or methanol), during the winding process. The solvent may be diluted with water, as required, but the strength of bonding is reduced.