Don't laugh - tarpish boat?

Discussion in 'Boatbuilding' started by jdarling, Jun 23, 2009.

  1. jdarling
    Joined: Jun 2009
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    Location: Kansas City, Mo

    jdarling Junior Member

    Just to give everyone a good laugh and to hopefully get some answers I thought I'd register, relay my story, and ask what are probably stupid questions.

    A warehouse near me recently put an ad on craigs list talking about having a bunch of shipping air bags (I have pictures). I just had to go look, upon arrival I noticed these were 46.5"x108" bags that were water tight and air tight. Like a fool I loaded a few palettes home with me (sounded like a great idea).

    Got home, tore into one of the bags to find that the inner workings were a very heavy duty (1/16" thick) plastic bag (fun fun for the kids) while the outside is a massively heavy duty tarp like material (white in color).

    I scavenged together some lumber I had lying around the house and built a quick 8' row boat frame with a nice transom out of 1" ply that I had. Took one of the interior plastic bags and covered the stitch frame then stapled it to the frame for good measure.

    Threw it in the pool. What Water line... This thing didn't even sink in 1/2". Ok next step. Took a few of the outside coverings, found some fiberglass resin in the shed and tried covering it and resining the "plastic cloth".

    Long story short... The resin WON'T stick to this stuff. In fact, I can't find anything that will stick to this stuff. Out of spite (and a bit of heat stroke) I event tried great stuff, came off like it was teflon.

    So, here I sit with a clear plastic boat with minimal ribbing that needs to be covered and stiffened up. I'd like to keep using my surplus bags, but can't figure out anything to "glue" them together and attach them to my frame.

    Any ideas?

    I'd like to have this for my boys to play with in the local creek. Just want it to be a bit more stable than it is now.

    PS: Things I've tried so far (in no particular order): Fiberglass Resin, Sub-Flooring Cement, Thompsons Water Sealer (sounded like a good idea), lots of misc tubes of stuff I had lying around.

    Thanks,
    - Jeremy

    PPS: The outside "plastic fabric" is pellet proof from a high powered air gun (my son wanted to see if it was "kevlar"). Might not have been a good idea, but I was surprised it didn't go right through.
     
  2. apex1

    apex1 Guest

    Make yourself a RIB! The stuff sealing the tarp used to make garden ponds should stick it together! "Adamgrip" is one 2k glue I know, used on inflatables. Otherwise heat could do the trick (I would try that first).

    Regards
    Richard
     
  3. Stumble
    Joined: Oct 2008
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    Location: New Orleans

    Stumble Senior Member

    By "fiberglass resin" what do you mean? This could be anything from a two part epoxy to bondo.

    Either way from what I could find most of these bags are made from polypropylene or polyethylene neither of which work well with pretty much anything. Assuming this is what your bags are made of take a look at 3M's Scotch-WeldTM Structural Plastic Adhesive DP-8005. I have never used it before, but 3M products seem to always work well.

    If you can identify exacally what material the bags are that would help out a lot in telling you what adhesive you need though.
     
  4. jdarling
    Joined: Jun 2009
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    Location: Kansas City, Mo

    jdarling Junior Member

    apex1, interesting on the Adamgrip. Any good retailers that you would recommend on that one? I have a PVC boat that I've tried everything to patch as well. Maybe that's what I need to try :)

    Stumble, what I tried was Elmer's "All-Purpose Fiberglass Resin" from Lowes. I'd like to find something I can use to build up layers of the bag material much as you would fiberglass.

    From what I can find (and believe me there isn't much info on these bags) you are correct in your assumption that they are polyprop or polyeth in nature. They come from 3 different mfg's but none post the specs on what they are made from, just what they can be aired up to and what they will handle impact wise (PITA).

    My "ideal solution" would be something I could roll or spray on the existing plastic and start layering up my bags until I have a hull about 3-4 layers thick that would withstand boys in a creek :). The Scotch-Weld looks interesting, but all I can find it in is tubes :(

    If it is polyprop would standard plumbers PVC cement work on it? Course this might cause a problem with shattering instead of giving once layered.
     
  5. apex1

    apex1 Guest

    Sorry mate, no idea, I am on the "right" side of the pond! But Adamgrip is the right stuff for your PVC boat.
    The Tarp:
    If its PP or PE I´m lost.

    Regards
    Richard
     
  6. Stumble
    Joined: Oct 2008
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    Location: New Orleans

    Stumble Senior Member

    I would suggest taking a couple of test samples and trying small batches of different stuff on them. But I am willing to bet that what you have is polypropylene or polyethylene.


    Just a few ideas off the top of my head:

    You could try a small batch of two part epoxy from WestSystems, but it likely won't stick at all.

    You could try to disolve the tarp with MEK then stick it together, Though this is probably going to be messy and a pain in the...

    vinylester resin might work. But be forwarned this stuff is horrible to work with.

    Heat, though for a panel it might be a problem to get the heat applied evenly enough.

    PCV glue... another chemical disolver like MEK. Probably pretty expensive for a large panel.

    There are a number of contact adhesives made to work with plastics, but I have never worked with any of them.

    Basically the problem is that polypropylene is intended not to stick to anything (it is used to make superglue bottles for gods sakes) so you are trying to work around what a specialty material was made for. It may honestly be easier and faster to go buy some canvas, spread it on the frame, then epoxy it. The boat won't last very long, but it will be light, waterproof, and should last a while if you keep it out of the sun and don't let the fibers absorb water.
     
  7. BHOFM
    Joined: Jun 2008
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    Location: usa

    BHOFM Senior Member

    Fine a place that sells chicken house supplies and get
    a roll of curtain repair tape.

    It will stick to anything and it will stay stuck!
     
  8. jdarling
    Joined: Jun 2009
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    Location: Kansas City, Mo

    jdarling Junior Member

    Time to start working my way through the list of products. Guess the good news is that I have PLENTY of sample material :). So far my list contains; 3M HiTack Spray Adhesive 72, 76, and 90, MEK, curtain repair tape, and heat fusion.

    What I've tried (and didn't work):
    PVC Cement (plumbers glue) many types (gotta love the plumber neighbor)
    Floor Adhesive (actually, this grabbed but would take years to set)
    Construction Adhesive (this sorta worked, but would look like ****)
    Different other bottles of glue found in the garage

    I'll keep you up to date as I try new things.
     
  9. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Try heat. A regular iron should melt the plastic and weld it. To prevent the plastic from sticking to the iron use newspaper on both sides. We use to make tents like that.
     
  10. ancient kayaker
    Joined: Aug 2006
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    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    Instead of sticking something to the outer material, why not sandwich ribs between the inner and outer layers so they are held in place by pressure? It would be best if the ribs had a lot of area in places, maybe ply plates at the ends, to increase holding power. You could also run canvas strips around the inner bag, attached to the ribs, to improve holding power. Then if you cut some holes in the outer layer you can attach the external parts of the frame to the ribs.
     

  11. jdarling
    Joined: Jun 2009
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    Location: Kansas City, Mo

    jdarling Junior Member

    Bit of an update, the 3M 72 and 76 didn't work worth beans. The 3M 90 on the other hand stuck it together like it was meant to be. 1 can later I have a frame covered in high mil plastic and a layer of this tarpish material. I'm up to painting now, trying to decide what will stick to the slick surface. Thought about Rhino type glue, but afraid it will melt. Will play around with more scraps and see what I come up with. Either way I'll post as I make progress.

    - Jeremy

    PS: 2 part epoxy didn't work to hold it to the wood, but good ol staples worked with 3M 90 under them.
     
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