Hello Don,
Bad, but true facts: Polyethylene (PE) is not really paintable. PE belongs to the group of Polyolefines.
Wikipedia says: Polyolefin surfaces are not effectively joined together by solvent welding because they have excellent chemical resistance and are unaffected by common solvents. They can be adhesively bonded after surface treatment (they inherently have very low surface energies and don't wet-out well (the process of being covered and filled with resin)), and by some superglues (cyanoacrylates) and reactive (meth)acrylate glues. They are extremely inert chemically but exhibit decreased strength at lower and higher temperatures.
In other words; not really glueable. Of course you can try to glue it, but do not look too sharp onto it and don't cough. It may fall apart into pieces again.
Exact the same behavior is with paint, dye and all other laquer stuff. The adhesion of paint is based onto wet-out effects and a not so chemical resisting surface of the plastic (bonding). The chemical resistance of PE also here makes sure that no paint will stick firmly onto the surface. Here too don't look too sharp onto it, don't cough in the same room, avoid draft and do not move the painted PE parts. Flaking off paint will be the inevitable result.
Make a test: https://www.bottompaintstore.com/blog/bo...bt-blends/
There are further possiblities of treatments for the stubborn PE surface, including electrical corona
discharge, flame treatment, cold gas plasma, and ultraviolet irradiation. But this are industrial grade procedures and not acessible for hobby model railroaders.
Lutz
Bad, but true facts: Polyethylene (PE) is not really paintable. PE belongs to the group of Polyolefines.
Wikipedia says: Polyolefin surfaces are not effectively joined together by solvent welding because they have excellent chemical resistance and are unaffected by common solvents. They can be adhesively bonded after surface treatment (they inherently have very low surface energies and don't wet-out well (the process of being covered and filled with resin)), and by some superglues (cyanoacrylates) and reactive (meth)acrylate glues. They are extremely inert chemically but exhibit decreased strength at lower and higher temperatures.
In other words; not really glueable. Of course you can try to glue it, but do not look too sharp onto it and don't cough. It may fall apart into pieces again.
Exact the same behavior is with paint, dye and all other laquer stuff. The adhesion of paint is based onto wet-out effects and a not so chemical resisting surface of the plastic (bonding). The chemical resistance of PE also here makes sure that no paint will stick firmly onto the surface. Here too don't look too sharp onto it, don't cough in the same room, avoid draft and do not move the painted PE parts. Flaking off paint will be the inevitable result.
Make a test: https://www.bottompaintstore.com/blog/bo...bt-blends/
There are further possiblities of treatments for the stubborn PE surface, including electrical corona
discharge, flame treatment, cold gas plasma, and ultraviolet irradiation. But this are industrial grade procedures and not acessible for hobby model railroaders.Lutz