In Reply to: some additional information posted by Garrett on 05/25/02 at 3:17 AM:
A few points on your problem:
1. ABS is a reasonably UV resistant thermoplastic, so I am guessing that your environment has a LOT of UV exposure.
2. If your ABS was not specifically formulated to be UV resistant, you are not getting the best UV protection out of the material you have tried. Most materials will have a designation (or suffix) of UV if they include UV stabilizers.
3. Black is the best color for UV resistance, and the carbon black (the typical colorant in a black material) is an excellent UV stabilizer.
4. Some other materials to consider: PET, PP, ASA. Note that you should specifically get UV stable versions of these materials.
5. A higher end, colored, UV stable material which might work, but cost more money, is DuPont's Reflection Series. It is a combination of surlyn ionomer and nylon 6. The stuff looks great, and is very UV stable.
Hope this helps. You didn't specifically say if this part wall injection molded. If you are fabricating from extruded sheet stock, you might have troubles finding these materials.
Good luck, and thanks for posting here.