How does solvent welding work?
The solvents in the cleaner remove residues that may be on the pipe, leaving a good clean surface. The primer solvents begin the softening process, “etching” or penetrating the pipe. By doing so, the plastic begins to soften and swell. Cement is similar to primer, but contains higher concentrations of active solvents and dissolved resin, similar to the plastics in the pipe and fitting being welded. The pipe and fitting are both coated, connected and bottomed out, and given a 1/4 turn to ensure an even distribution of the cement. The swelling and the tapered shape of the fitting will cause the pipe to attempt to “push-off” of the fitting, so some resistance must be applied until the cement takes a “set”. The set usually only takes a minute or two to allow for gentle handling of the joint. The “cure” is the slow increase in strength of the joint. This process involves the evaporation of solvent out of the joint, completing the weld.
