Windshield Repair Kits - do they work well?

Discussion in 'General Motoring' started by techman41973, Jun 1, 2007.

  1. techman41973

    techman41973 Guest

    I have a small impact on my on my windshield from a rock the size of a
    pencil eraser along with a hairline crack about 1/4 inch long. I want
    to have the windshield repaired so the crack doesnt grow. Most places
    want $50 to repair it. My car is old and I plan to get rid of it in
    the fall.
    I noticed that Permatex and Loctite make repair kits for about $10
    that include a syringe and a crazy-glue like adhesive that supposedly
    fills the crack.
    Can anyone attest to the effectiveness of these kits and the
    difficulty in using them properly?
    techman41973, Jun 1, 2007
  2. techman41973

    sdlomi2 Guest

    I've tried them several times, practicing first on cheaper cars (was a
    dealer). Never graduated to more expensive cars, as my expertise was
    lacking. One really needs some specialized equipment(magnetized arms to
    position magnifying glasses, proper heat source, proper light sources,
    vacuum devices, glass-drills and training to fix them--esp. those having a
    short crack. Thart short crack can run full width of w/shield before you
    know it. Plus, I never could make the spots & stars virtually disappear,
    like the pros could do.
    Answer: pay the extra for a pro--the pencil-eraser-size would fade to
    the size of the lead-pointed end; and the crack quite often is hidden and
    they very seldom "run"--pros drill/fill the end of the crack to stop its
    running. If it were me, I'd pay the $40 difference and feel as if I was
    gonna get my $'s worth! Luck, whichever way you go. s
    sdlomi2, Jun 1, 2007
  3. techman41973

    Brent P Guest

    I used the permatex and fix-a-windshield brands on a very small
    chip/crack. The permatex looked great for a few days then it was almost
    like I did nothing. This was in winter so conditions were marginal. I
    tried another application in better weather but didn't get a good seal. I
    then tried the other brand that used a different application method. It
    didn't do much. I couldn't get to the base of crack, but it got the rest
    and that has held up for a couple months now. It is sealed, it's much
    less visible, but it's far from perfect.

    The only reason I tried it myself is because the damage was the kind that
    would not progress any further if sealed up and is a
    'have-to-know-it's-there'. If I should encounter this again, I would just
    have it done.
    Brent P, Jun 2, 2007
  4. I have a small impact on my on my windshield from a rock the size of
    You have to follow the instructions _exactly_ to get good results.

    I've heard that the Permatex/Loctite kit works well on bull's eye
    damage but not for anything else. There's also a different kit,
    consisting of 2-part epoxy, that works on both bull's eye and star
    cracks, and a friend of mine had good luck with it. But it took
    something like 45 minutes to apply the epoxy (he did it in the office
    parking lot during lunch) because the plunger had to be manipulated in
    different ways over the period to work into the entire crack and
    remove air bubbles (push it down and hold it down with a pin, pull it
    up and hold it up with a pin, plunge and release several times and
    leave it down, pump several tiems and leave it up).

    I'd rather spend the $50 to get the repair done right and prevent
    further cracking that could require replacing the windshield.
    larry moe 'n curly, Jun 2, 2007
  5. techman41973

    Steve Guest

    They seem to work OK, and are easy enough to use. I wouldn't use them on
    a long crack, but I filled a pit that sprouted a 3" crack on one of my
    cars with one of these kits, and the crack hasn't grown any further and
    the pit is much less visible after being filled.
    Steve, Jun 4, 2007
  6. If you care mostly about keeping the crack from growing, and don't care
    too much if the chip stays there, you can stop-drill the crack with a
    Dremel tool and a small silicon carbide stone. Dremel #83322 is ideal.
    Drill just a bit beyond where you can see the end of the crack. Hold the
    Dremel at just a bit of an angle, and rock it back & forth a bit. Be sure
    to go all the way through the glass layer or you won't stop the crack;
    it's pretty obvious when you hit the plastic. Then press on the area to
    make the crack extend into the hole.

    Dan Youngquist, Jun 4, 2007
  7. techman41973

    Dean Guest

    You are not using a tungsten carbide glass drill (spade shaped)?
    Dean, Jun 4, 2007
  8. No, a silicon carbide stone. I've never tried tungsten carbide, so I
    can't say how it compares, but silicon carbide is what Dremel recommends
    for glass. I use this one, because it's the smallest diameter Dremel

    Dan Youngquist, Jun 5, 2007
  9. techman41973

    DeanB Guest

    Ok looks good. Have Dremel, will drill!
    DeanB, Jun 5, 2007
  10. techman41973

    DeanB Guest

    Are you cooling the glass when you drill? Adding oil or water to
    DeanB, Jun 5, 2007
  11. No, in my experience it's not necessary. Of course it generates some
    heat, but you can touch the glass immediately after lifting the tool.

    I use a medium speed, and don't press hard, let the RPM's do the work. A
    grindstone isn't made to go straight in like a drill bit, so you have to
    wobble it a little, and I find it best to hold it at just a bit of an
    angle. It'll take a few minutes to get through the glass.

    Dan Youngquist, Jun 5, 2007
  12. techman41973

    jim beam Guest

    you don't want to do that if you want the sealant to stick!
    jim beam, Jun 6, 2007
  13. techman41973

    z Guest

    Just a pinole with a bullseye, work pretty good. with a crack; maybe
    not so good. you use the syringe to suck the air out of the bullseye,
    then to fill it with crazy glue. if you can get rid of all the air,
    the crazy glue almost matches the refractive index and it's almost
    invisible. the original pinhole remains. with a crack, it has to be
    small enough that you can effectively get all the air out without more
    leaking in through the edges under the suction cup. then if you pass
    that hurdle, the crazy glue doesn't really disguise a crack the way it
    disguises the bullseye under the glass in the center of the
    windshield. then, it doesn't have enough strength to really keep the
    crack from propagating over time as they so often like to do.
    z, Jun 7, 2007
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