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Fibre Glass Or Plastic

Discussion in 'Bling and Appearance' started by dannyg1985, Apr 19, 2006.

  1. I'm hoping you will be able to help me out with my question.

    what is the difference between fibre glass fairings and plastic ones?
  2. Fibreglass is stronger than plastic and also has a weight advantage, but it is more difficult to form and can only be patched if it's damaged. Plastic (usually ABS resin) can be formed into more complex shapes and is cheaper to produce, it can also be repaired by welding - either chemically or with heat.
  3. so is it better to get plastic of fibre fairings then..?

    what would u choose?
  4. Well fibreglass offers the advantage of reducing weight (slightly) but it's going to cost more and if you damage it too badly it'll need to be scrapped. So fibreglass is great for track bikes but for road use plastic is far more durable (personally I prefer not to have any fairings :)).
  5. I would beg to differ on this point. The only reason fibreglass fairings are more expensive to produce is because of the labour content involved. Fibreglass is superior in all other ways.
    From personal experience fibreglass can be repaired much better than plastic. Plastic welding is only really a band aid fix. It will never have the same mechanical strength as the parent material. Fibreglass can be repaired to give the same properties as before or near as damn it.
    However if you are replacing plastic fairings with fibreglass replicas then the finished product will depend on the skill of the person who made the molds for the fibreglass replicas & then laid up the fairings. Not the properties of the fibreglass.
  6. Eh? You might be able to patch up the resin (which will still create a weak spot) but if the glass fibres become broken or damaged they cannot be repaired, you can only apply a fibreglass band-aid to the damaged area and hope that will carry the required load. Since ABS resin is a thermopolymer when melted and reset properly it should be just as strong as when it was originally produced (by melting and resetting).
  7. Hey jd, have you actually tried repairing both materials? You know -got your hands dirty & physically tried it? I agree -if you do a cr@p repair on fibreglass, like tipping on some resin you will get a cr@p result. But if you properly prepare the surrounding area & lay up some glass fibre tape or cloth with the proper overlap it will be strong as new.
    Your theory on plastic is fine. However in practice it does not seem to work out. I always seem to get a brittle area around the weld. This seems to only happen on motorcycle plastic. I think they may use lower quality or different spec plastic in the fairings. Some manufacturers will even say not to bother trying to repair. (I have done a bit of pipe welding & it does not seem so bad) Still not as strong as the parent material.
    I have had a little bit to do with ABS plastic fabrication & the welds do not seem as strong as the parent material. No lab testing mind you but "weld it & try & break it type testing" I am no expert on the subject but merely relating my experiences with both.
  8. Yep I've had some experience patching (car) fibreglass before and yes patches do work okay - I'm just saying that the strength of the repair is only going to be as good as the bond between the old fibreglass and the new. You're not really "fixing" the old material, more attaching another piece and hoping it can transfer the load. I've done some chemical welding on small stuff and the results were okay (but not great) however I have worked with professional plastic welders (on pipelines) and can assure you that when someone actually knows what they're doing the weld is definately just as strong as the original material (saw plenty of lines fail but never at a weld point).
    Edit: If you're using heat to weld plastic then the temperature needs to be very carefully controlled - heating too far above the melting point will cause it to degrade.