[pentoad]

Originally Posted by emeritus

I use EMA Plastic Weld, which is actually methylene chloride (dichloromethane), and it does indeed work well by capilliary action. I used it recently to repair the transparent window for the tuning scale of a transistor radio that had been shattered when something sharp fell on it. It works by dissolving the plastic it is in contact with, and is so volatile that a thin layer of solvent on the surface evaporates before it can affect the surface finish of the plastic, and is so thin that it readily wicks into cracks. I apply it using a small artists' paint brush. I get mine from a local shop that sells model railways and accessories.

If transparency is not required, you can reinforce by applying polystyrene sheet across the cracked area. Funnily enough I did this only yesterday with the hinge of my Epson printer that had snapped when I had inadvertently put something heavy on the top. I first joined the broken pieces and, because the hinge had to be resiiently deflected to engage the housing, plated over the join with a piece cut from 1mm styrene sheet. As the solvent is so volatile, this required flooding the surfaces of hnge and plate first to soften them up before pressing together and then applying more solvent to the exposed edges. Oce the solvent has diffused away, the resulting structure is very strong as the plasic layers unite into a soid mass.

Thanks - I will try it out