Bedding Compound or Epoxy?

Discussion in 'Materials' started by Phil Westendorf, Oct 22, 2012.

  1. Phil Westendorf
    Joined: Jun 2012
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    Location: Saginaw, MI

    Phil Westendorf Junior Member

    I've been looking through this site several times now and can't seem to find exactly what I am looking for. Lots of info on bedding and adhesives, but....
    Here's the situation, I am building a 16 ' McKenzie River Drift Boat. I am looking for a way to attach the side panels to the framing. Sounds like a simple thing that could be answered by several of the forums dedicated to this type of boat. But, I have deviated from the norm. The side panels are built-up 1/4" Cedar Strips w/ 6 Oz. Glass with three coats of epoxy on both inside and outside surfaces. The boats frame; stem, 9 frames, chine log and inner sheer rails are white ash w/ two coats of epoxy.
    The side panels were laid-up on the frame and the outside surface was epoxied while still on the frame. No metal fasteners have been used to date, tapered trunnels (dowels) have been used in framing in stressed joints. My goal is, NO SCREWS/BOLTS.
    Now I am looking a way to secure the side panels to the framing prior to building a cold molded bottom panel (1/2").
    My original thought was to use West's Six-10 thickened epoxy to attach the side panels. This stuff worked great securing the Inner Shear Rails to the Framing. Having read several posts on this site and others I have become concerned about the side panels being hard fastened to the frame pieces causing "stress risers". The glassed cedar strip panels, IMHO isn't as stiff as the normal 1/4" marine plywood sides in a typical drifter. Being in MIchigan we don't have the white water like you'd find out West. I have read several "cautions" about 3M's 5200 and its great sticking ability, limiting ability to make repairs easily, not that I think that's something I'd like to do anyhow.
    So I am asking for your opinions, anybody have any suggestions to secure the side panels?
    phil w.
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Use the Six-10 or just a thickened epoxy mixture. The last thing you want is the rigidly bonded strips to "work" against the framing, as it would with a sealant/adhesive, like 3M-5200.

    Were the strips edge glued and with what? If they're not edge glued, you'll probably need one of two things; a much heavier sheathing and/or fasteners in each strip, into each frame.
     
  3. Phil Westendorf
    Joined: Jun 2012
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    Location: Saginaw, MI

    Phil Westendorf Junior Member

    Par,
    I appreciate the quick reply. The 1/4' Cedar Strips are Bead and Cove with Titebond II glue. I built a 16 ft. Peterborough Canoe a few years ago using the same technique without any problems, but there's no permanent framing to deal with therefore my concerns.

    I like working with Six-10 as it is really easy to apply and clean to work with. For this kind of application it's well worth the cost. I 'll take your advice and do it with the Six-10 as your statement makes a lot of sense.
    thanks,
    phil w
     
  4. Phil Westendorf
    Joined: Jun 2012
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    Location: Saginaw, MI

    Phil Westendorf Junior Member

    Epoxy, Resin or what?

    I have another problem similar to the original one above, and am looking for a material (glue) to secure two layers of strip planks to one another. I am building a bottom for the drift boat from two layers of 1/4" thick x 2 1/2" White Ash, Bead and Cove.
    The strips are glued together with Titebond II. It will be glassed on top and bottom after it is completed and secured to the Framing with West's Six-10 Epoxy. It worked slick on the side panels.
    The first layer runs fore and aft, 19 strips total. It was built on a sheet of tempered hardboard secured temp. to the framing. I have sanded it fair and it's pretty flat except in one small area where two strips buckeled about .060-.070" near the Port side aft.
    The second layer, made also from similar strips are planned to be oriented 60 degrees to the first. I am considering building the second same as the first on top of it. I am not too experienced in laminating wood like this.

    I have all the stock cut and was planning on glueing up three strips at a time and then permanently securing them to the first layer with an adhesive. I have a decent vacuum pump and could vac. bag it to apply clamp pressure.
    What to use is the question I am looking for....

    Urea-Resins aren't suited from what I can tell, this application needs a little gap filling characteristics.. Thickened Epoxy will work, but it's below 32 degrees outside now and I can just get the garage to 55-60 degrees after 4-5 hrs. Spring is too far away to wait for decent temps. Titebone II might work but I am not too sure it'll do the job from a structural perspective. I don;t need the bottom layer separating if the boat hits a stump, rock, etc. Is there something that's commonly used besides 3M 5200.
    Any assistance is welcomed.
    phil w.
     
  5. spenance
    Joined: Dec 2010
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    Location: Hammondsport, NY

    spenance Junior Member

    Tent the boat with plastic and put electric oil filled radiators underneath to bake the boat for cure. One bit of advice would be to keep the boat dry and out of the weather when not in use. I have seen lots of ash severly rot if coated with epoxy and moisture will get in.
     
  6. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    Right. Tent the boat. The nice thing about epoxy is that it will wait in the cold and not kick until such time as the temperature has sufficiently risen. This allows you the time to set up a poly tent after you've finished the work.
    Screws or bronze staples are great for temporary hold-downs.
    One aspect of cold that makes things easier is that you can work from much bigger epoxy batches allowing you to concentrate on laying strips in a relaxed manner.
     
  7. Phil Westendorf
    Joined: Jun 2012
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    Location: Saginaw, MI

    Phil Westendorf Junior Member

    Don't know what the heck I was thinking, should have focused my effort trying to find a way to heat the boat/epoxy. I caught up looking for a "miracle glue" that does what epoxy does but in the cold.
    I agree with both replies. Now I'll focus my efforts on building a tent and finding a heat source that's safe. If it's worth doing it's worth doing it right.
    Thanks, your help is appreciated.
    pw
     

  8. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Spenance has it right and it's the same way I do it. Wal-Mart has oil filled (electric) radiators for 15 bucks or so. I have four or five of them and they work great. If you want more heat, take off the front cover and replace or detach the thermostat. I have a commercial, adjustable thermostat on one and none on another. There's still a thermal trip that will keep it from catching fire or exploding from an over heat, but it does let it get a lot hotter.
     
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