Dichloromethane, or methylene chloride, is an chemical-organic compound from the chlorinated hydrocarbon group (molecular formula CH2Cl2). This colourless liquid has a typical odour similar to chloroform, is only slightly soluble in water, is lightly volatile (always close your container tightly) and has low flammability in the air.
Dichloromethane is used as a paint stripper and degreaser as well as as a solvent for resins, fats, plastics and bitumen. It is also used as a means for gluing thermoplastic plastics like polystyrene, acrylic glass, polycarbonate, PET-G and ABS (a “diffusion adhesive”). In this application, the plastic is etched (solvated) and seamlessly “welded” together. In model making its ability to quickly make a transparent bond on acrylic glass materials without having one´s finger become stuck as well is highly prized. The plastics polypropylene and polyethylene are not soluble and therefore cannot be glued with dichloromethane. It can also serve as a degreaser or solvent for resins, fats, plastics and bitumen but, it should be noted, according to Decision No. 455/2009/EU from the European Parliament (amends Council Directive 76/769/EEC - conveyed in Appendix XVII of the EU REACH Regulation) it may no longer be used as a paint stripper.
Making a bond with a solvent is very easy. The precisely cut assembly pieces are held together, the liquid applied to the joint with a brush and a short amount of time is then allowed to pass. The solvent flows into the joint, solvates the plastic and the pieces become bonded. This technique is not suitable for bonding large areas because the organic solvent evaporates too quickly. Methylene chloride, it should be noted, is a volatile and toxic liquid. Its vapours can irritate eyes, skin and breathing passages considerably and it is suspected of being a cause of cancer. You should therefore always store it in tightly closed containers and pay close attention to the safety and disposal information given above in detail.