Frame damage (gash) - repair possible?

El Diego
El Diego Posts: 440
edited June 2010 in Road beginners
My bike has a deep scratch and on the downtube. The scratch is purely cosmetic, but its bugging me. Can anyone recommend any techniques or people who could repair this? I'm based in Manchester.

Comments

  • andrewjoseph
    andrewjoseph Posts: 2,165
    what material is the frame made from? if carbon then I would get it checked by the manufacturer as this may have delaminated the carbon on the inside.

    regardless of the material, a deep scratch may compromise the strength of the tubes, I'd get it checked out before trusting it.
    --
    Burls Ti Tourer for Tarmac, Saracen aluminium full suss for trails
  • El Diego
    El Diego Posts: 440
    It's an Alu Caad9. The scratch has gone down to the metal but it doesn't look deep enough to compromise the structural integrity of the tube. I'll post a pic when I get home.
  • MattC59
    MattC59 Posts: 5,408
    If the scratch hasn't damaged the base metal, just go to Halfords and get the closest matching car touch up paint and some T-Cut.

    Actually, get in touch with Cannondale and ask if they've got a touch up paint for your CAAD 9.

    The best way to touch it up is with a cocktail stick. Sounds daft, I know, but it allows you to put small amounts of paint on and fill the scratch, rather than just sloping it on with a brush.

    Build up layers of paint, letting each one dry then use the T-Cut to polish the surface. Depending on how bothered you are by the scratch, you can get a near perfect result with this method.

    If you do want a good finish though, be patient !!!
    Science adjusts it’s beliefs based on what’s observed.
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  • rake
    rake Posts: 3,204
    after painting the best way to level is rubbing compound available at halfords. either aerosol looks like shaving foam or in a tin like orange paste. use a rag and lots of rubbing. its like sanding but leaves no marks. then polish it.
  • porker33
    porker33 Posts: 636
    Both reasonable suggestions,

    With a cocktail stick you tend to get blobbing the end, it is ok for minor stone chips, but anything more you may as well spend £1 on a fine modellers detail brush, something in the 1-1.5mm range from a decent toy/model shop.

    Rubbing/ cutting compound can end up rubbing the paint out of the groove. Best thing is to paint in the groove/scratch, then rub very gently with 2000 grade wet n dry, this takes the top off of the paint you applied, leaving it matt...paint again to fill in any evident gaps...rub down and repeat, then again if neccesary...at this point it will look terrible!....all flat and matt, sparingly use the finest compound you can find to bring shine back, i.e, 3M finesse it or even Brasso if you must...then apply a wax to seal

    I have used the above method to repair scratches on some quite expensive cars with good results...I am sure it would make a difference on a bike frame with thicker paint...

    Good luck and take your time to build the layers up. .
  • El Diego
    El Diego Posts: 440
    Thank you for the suggestions. I have emailed Cannondale to see if they have a touch up or paint code. I think I will get a modellers brush and build up the layers as suggested.

    One think I forgot to mention is one of the scratches has a slightly raised edge that will need filing down, can anyone suggest a good method or do you think I'm better paying a pro to do the work?
  • porker33
    porker33 Posts: 636
    If the raised edge is paint, use the 2000 grade wet n dry mentioned above, if it is aluminium, then you may (or may not) have bigger problems, so get a pro to check out the structure of the frame has not been compromised.
  • El Diego
    El Diego Posts: 440
    It is a small raised bit of aluminium. When you say get a pro to check the structure of the frame, do you think someone at a bike shop will know?
  • porker33
    porker33 Posts: 636
    I would expect a Cannondale dealer to have more idea than us, they would have seen all sorts of bikes come through their workshop and be aware of any potential problems..good luck.

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