Fiberglass repairs and acetone

Discussion in 'Materials' started by Ittiandro, Sep 17, 2016.

  1. Ittiandro
    Joined: Sep 2016
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    Location: montreal

    Ittiandro Junior Member

    I have a 75% carbon 25% fiberglas windsurfing mast. I found a small hairline crack ( probably while dragging the mast). Nothing structural, only superficial, but I wanted to strengthen the area by wrapping a 2 “ wide fiberglas patch ( Bondo polyestyher resin) around the dent.

    While working on the patch I have slightly smeared the area with resin . It is only some light residuals of hardened resin, small lumps at most . They are almost imperceptible visually, but I want to remove them because they have taken away some of the glossy surface of the mast which is almost new and are a bit rough at the touch.
    Can I clean them with acetone without risking to damage ( or even dissolve ) the underlying original fiberglas( or epoxy, I'm not sure) material? I don’t want to sand them away because this will defeat my purpose and further dullen the surface.


  2. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    Acetone won't damage epoxy or polyester resin if all you're doing is cleaning the surface, but it may damage paint. It may also dull the gloss slightly, so check first before doing a large area.
  3. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    I would be surprised if your mast is made of anything other than epoxy and really you ought to be using epoxy for the repair.Using acetone to remove contaminants is probably a reasonable idea,you may need to accept that the shiny finish on the mast is lacquer and may be removed by the acetone.
  4. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    This sounds more like a scratch than a crack. I can't hardly imagine a crack not being structural.

    If so, then that old joke would seem to actually apply here... "That'll buff right out."

    If there wasn't any structural damage, why try and reinforce the thing?

  5. redreuben
    Joined: Jan 2009
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    Location: South Lake Western Australia

    redreuben redreuben

    What wet feet and SamSam said.
    Your polyester patch is wasted on an epoxy mast.
    Contact the mast manufacturer, remember, perfection is the enemy of good.
    Meaning your search for perfection may well ruin a good mast.
    I'd be inclined to use very fine wet and dry sandpaper and a lick of cutting compound.
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