1968 Saftmate - Stringer Work and Question

Discussion in 'Fiberglass and Composite Boat Building' started by atengnr, Sep 25, 2019.

  1. atengnr
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    atengnr Junior Member

    Hello all, have this 68 saftmate that has been in family since new. Long story shortened, in 2009, I had a local shop replace center stringer, and floor (I had done side stringers and floor in 1990s). Shop did a substandard job, as they did not tab the stringer, only used a resin chopped glass paste to bed stringer down. Also they did not glass the floor on top. Finally getting around to fixing this, but also noticed that an old crack repair that shop did has cracked again (this was from damage done from a chisel into hull during my work on it in 1990s).

    So, what is my best course of action? Stringer is solid, but open to environment. Should I remove all of floor to glass stringer in correctly? How should I fix the crack (inside or outside?). Any thoughts on modifying stringer design to make this boat more solid (I do like to take this boat out on great lakes occasionally, and it gets beat up, albeit at 10mph)???

    Thanks alot.

    IMG_2482.jpg

    IMG_2481.jpg

    IMG_2480.jpg
     
  2. atengnr
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    atengnr Junior Member

    Would anyone offer some advice? Thanks alot!
     
  3. kapnD
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    kapnD Senior Member

    Pretty difficult to do so based on info and pics provided so far.
    Any work on this hull will easily exceed its worth, so it’s up to you to decide whether or not to go forward with repairs
     
  4. KeithO
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    KeithO Senior Member

    I agree with others that this only make sense as a sentimental type project.

    I had the exact same model, in olive green. Due to the flat bottom nature of the hull, rain water will easily accumulate in the hull and fill the void between the bottom and the floor, so whatever is in there had better be waterproof... i acquired mine for $1600 with a running Mercury 50hp motor about 7-8 years ago. Eventually I had too many reliability issues with the mercury motor, which included the wiring of the engine crumbling and most of the parts being obsolete or prohibitively expensive. So I scrapped out the boat.

    My suggestion would be to use wood free stringers, just fiberglass cloth laid up 1/8" thick in an inverted "U" shape which will self drain. You could mold the stringer over a piece of PVC pipe that was set on top of a piece of flat material. If you can fill the gap between flat and round with something like expanding foam and shape it slightly tapered to ease getting the individual stringers off after they set up, that would be a quick way to make a mold.
     
  5. fallguy
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    fallguy Senior Member

    Encapsulate all raw wood in epoxy.

    If you want you can bond the sole down with a thixotropic epoxy mix or you can use 3M 4200.

    If you want to tab the stringers; just get some fiberglass tapes and make an epoxy fillet with thixotropic mix and laminate the tape. A tape or two on each side of the stringer say 4" and 6" with edges not overlapping is fine.

    The chisel damage needs to be removed and refilled.
     
  6. Ike
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    Ike Senior Member

    When I did a similar repair on my 72 Sea Ray SRV 190 I first saturated the stringers with a penetrating epoxy, Then I glassed them in with tabbing to the hull. I saturated the sheet of plywood that would be the sole with penetrating epoxy as well and glassed it on both sides and edges. That way the wood is not exposed, And if any thing should crack the glass water won't penetrate the wood. It is more expensive and more labor to do it this way but it will last far longer. Boats collect water, whether it's a leak, condensation, rain, whatever. You want to prevent any of that water from getting into the wood.
     
  7. atengnr
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    atengnr Junior Member

    Thanks all. What about adding some bulkheads to stiffen this up a bit? The previous repair job included the addition of the half-arsed bulkhead as pictured. Id like to make this boat more durable for rougher water.

    Best to fix crack from outside or inside?

    Add foam?

    Thanks
     

    Attached Files:

  8. fallguy
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    fallguy Senior Member

    bh - no

    glassing over raw wood - yes
     
  9. atengnr
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    atengnr Junior Member

    Why no bulkheads?
     
  10. fallguy
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    fallguy Senior Member

    A bulkhead is an athwart structure.

    In this case, I can't see additional BHs adding much to the hull as much as simply good construction of the existing stringers.

    If the boat is floppy or twists readily, it is done and should not be used offshore or was never built for it.

    Adding a bulkhead would not be a remedy for such.

    Your pictures are a bit close for this assumption, but the boat is not that long. Bulkheads are used when the lengths are long.

    If you wanted to add some floor framing; you could do so, but I also doubt it will do much.

    A floor frame is a stiffener below the sole and a BH would generally be above the sole. (In general)

    So we could just be mixing terms.

    But, if you feel the boat is so loose it needs a bulkhead; dispose of it or don't go offshore.
     
  11. atengnr
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    atengnr Junior Member

    Thanks alot. Yes floor support i suppose was the right term. With the angle of outboard stringers nearer the front of boat they dont contact floor there and as such doesnt support hull up front. Would a support up front to link the stringers and floor in this area be useful?? See the first picture.
     
  12. atengnr
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    atengnr Junior Member

    What do you think of this crack? I cannot see it definitively on outside of hull but looks below inside surface. Its left of stringer running through woven tabbing and forward towards top of pic.

    Thanks
     

    Attached Files:

  13. fallguy
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    fallguy Senior Member

    I am sorry, but can't make it out.
     
  14. fallguy
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    fallguy Senior Member

    All you need is a cleat.

    Glue the cleat to the sole with thixotropic mix with aerosil and polyester or epoxy and let it set. Then set the sole in and glue it down after the glasswork.

    Not sure what happens to water in this boat, but you might not want t close off the flow.
     

  15. kapnD
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    kapnD Senior Member

    That crack is a result of not using a fillet in that sharp inside corner.
    The roving has been forced deep into the corner , weakening the fibers, probably with a corner roller.
    What’s all the lumpy looking stuff along the outside edges of the floor?
     
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