Plexiglas
 

I have problem where if left in sunlight the windows turn quite "milky". Any one know the cause and more importantly any one know a "cure" (other than new ones)?
thanks

You could try a good plastic cleaner, Plexus is very good but if that won't solve the problem it is time for new windows.

Transair sell Plexus but if you shop around you can find it at a much better price from the likes of Addams aviation or LAS aerospace.

Thanks A&C, I regularly use Plexus anyway. In this instance the glass is only affected by sunlight. In the shade it is quite as one would expect but in sunlight it very soon becomes quite "milky" and I should love to know why.

It sounds like someone has used the wrong solvent / cleaner on the surface. Plexiglas / perspex should not be affected by sunlight per se, although it is possible that a subsequent UV coating is degrading. Or just that the surface is contaminated with oil / grease that is reacting with sunlight.

From a datasheet:

plexiglas is a trade name for acrylic plastic.

Characteristics of the material

• Acrylic Plastic
• Half the weight of glass
• Impact resistant
• Unaffected by sun or salt spray
• Temperature range of -30 to 160° F for continuous service

Cleaning:
Wash with mild soap or detergent, with plenty of lukewarm water, dry with soft cloth or chamois.
Grease, oil or tar can be removed with hexane or kerosene. Solvent residue should be removed by washing immediately.
Do Not Use window cleaning sprays, scouring compounds, acetone, gasoline, benzene, carbon tetrachloride or lacquer thinner.

Plexiglas can be sanded and polished - but test on an inconspicuous area first! There are lots of resources on the web for how to go about sanding and polishing.

SD

Thanks SD I will try and clean a small area very thoroughly and se what happens.