Repair to outside crack - MEK or Epoxy (g-flex)?

Discussion in 'Miscellaneous Repairs & Maintenance' started by Sweet Chariot, Nov 30, 2009.

  1. Sweet Chariot

    Sweet Chariot New Member

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    Nov 25, 2009
    Burnaby/Okanagan
    Dear PUP Portal Friends,

    We recently picked up a new to us '04 Viking Legend 2170ST - but unfortunately it had a small crack above the front storage bin (which had been sealed with silicone by the previous owner). When the PUP is folded down [PUC], the crack is in the small area between the roof and the front storage bin.

    This crack expanded on our PUP's maiden 6 hr trip home [PUC] [TV] and needs to be repaired right away.

    We read many great posts on this site about using MEK ("plastic welder") and recommendations not to use epoxy for this type of repair. But has anyone tried using g-flex epoxy (http://www.westsystem.com/ss/g-flex-epoxy). This was recomended by a wise friend who is very experienced in boat repair - but not necessarily PUP repair. Apparently the g-flex expoxy is very good (and very expensive).

    Here is what the g-flex epoxy web site says about this epoxy:
    "A toughened, versatile, liquid epoxy for permanent waterproof bonding of fiberglass, ceramics, metals, plastics, damp and difficult-to-bond woods. With a modulus of elasticity of 150,000 PSI, it is a bit more flexible than standard epoxies and polyester, but much stiffer than adhesive sealants. This gives G/flex the ability to make structural bonds that can absorb the stress of expansion, contraction, shock and vibration. It is ideal for bonding dissimilar materials. It can be modified with West System fillers and additives, and used to wet-out fiberglass tapes and fabrics. Mixed at a 1:1 ratio, G/flex gives you 45 minutes of working time at room temperature. It reaches an initial cure in 7 to 10 hrs and full cure in 24 hrs. Click for photo. (8 fl. oz. / 236 mL)"
     
  2. Sweet Chariot

    Sweet Chariot New Member

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    Nov 25, 2009
    Burnaby/Okanagan
    We'll add a photo tomorrow [CAM]
     
  3. TwistedElvis

    TwistedElvis New Member

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    Jun 4, 2009
    San Diego, CA
    Yes a photo will help.
     
  4. I'd be interested in learning more about g-flex. I have a small crack in the front corner of my pup that I repaired with Bondo-Glas, but it reappears about every year or so. I'd love something permanent.
     
  5. bigdad

    bigdad Active Member

    3,594
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    Mar 5, 2007
    Springfield Kentucky
    I also would like to see some pic.
     
  6. Sweet Chariot

    Sweet Chariot New Member

    170
    0
    Nov 25, 2009
    Burnaby/Okanagan
    Pictures of crack:
    For big photos and caption: http://picasaweb.google.com/colinross1/Viking?feat=directlink

    And small photos here...

    The crack is visible between roof (with Viking lettering) to front storage compartment:
    [​IMG]


    and goes through to the inside of the front storage compartment:
    [​IMG]
     
  7. Sweet Chariot

    Sweet Chariot New Member

    170
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    Nov 25, 2009
    Burnaby/Okanagan
    We found a source for MEK (local Fiberglass shop) and ABS plastic (Rona sells ABS plastic chair legs for $7 each) to do the MEK/ABS plastic repair.

    Sounds the MEK/ABS would be best repair because the plastic is re-formed into a completely new bond - while any epoxy repair will just be holding the two broken parts together.
     
  8. xxxapache

    xxxapache Well-Known Member

    1,508
    88
    Jul 30, 2008
    MEK goo is the only way to fix ABS. I little piece of fiberglass cloth between the coats of MEK will make the repair very strong. Be sure to soften the area around the crack with a little MEK on a cloth, so the repair will solvent weld itself together. If you don't you will only be painting a new layer of ABS over the crack.
     
  9. Sweet Chariot

    Sweet Chariot New Member

    170
    0
    Nov 25, 2009
    Burnaby/Okanagan
    The MEK mixed with White Lego (left together with occasional mixing for 2 days in a glass jar) worked incredibly well. The mix had a consistency that was a little thicker than regular white glue and even on a cold day it really smoothed out after applying so the end result is ultra-smooth. Used about 5 coats for maximum durability - but had the feeling that 2 would have been enough.

    Can't wait until Spring.
     
  10. Sweet Chariot

    Sweet Chariot New Member

    170
    0
    Nov 25, 2009
    Burnaby/Okanagan
    Photos of repaired crack using MEK / white Lego method.

    http://picasaweb.google.com/lh/photo/wNnsP1PAaXg7mTnCEjSDXA?feat=directlink
    http://picasaweb.google.com/lh/photo/cZviZPeGiOQd7_jE2H3vXQ?feat=directlink

    [​IMG]

    [​IMG]

    These are photos after the second repair attempt by me. My first attempt did not work so well because the previous owner had put silicone in the crack and I did not clean it out enough. I removed the initial repair and then pulled out all of the silicone and sanded the area and also the edges of the crack to remove all of the silicone and then added MEK three times, leaving it for a week after each coat to really harden each time. Sometimes sanding between coats, but that was not needed because it smoothed itself very nicely each time.

    Tips for next time:
    -Take your time: When making the ABS plastic/MEK solution, just leave ABS in MEK for a few days. This removes the need to break up the ABS in any way, given enough time the MEK with "digest" the ABS.

    - Take your time (again): During the repair, really clean the area with MEK solution.

    -Before each coat, brush pure MEK over the area first to clean and soften the top layer of ABS.

    - Take your time (again): After adding the MEK/ABS solution, let it sit for a few days to really harden (if you put on a thick coat).

    - Wear gloves and don't breath the MEK vapors because they are very toxic. (I usually didn't do this, but I should have)
     
  11. Island Ranger

    Island Ranger New Member

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    Aug 14, 2006
    United Kingdom
    Some great stuff there guys I will have to mark this for future reference as I have a couple of small cracks that are sealed at the moment, thanks for the links
     

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