Sorry but another STRINGER post, please help

Discussion in 'Boat Design' started by kapaduch, Feb 19, 2007.

  1. kapaduch
    Joined: Feb 2007
    Posts: 2
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    Location: Raleigh, NC

    kapaduch New Member

    Hey Everybody,
    I'm a new member to this forum, but I have been reading literally hundreds of posts trying to figure out what I can do with these stringers. So here is the problem, I apologize in advance for the length of the message, but any help would be GREATLY appreciated.
    I bought this boat a couple weeks ago, its a 1966 Correct Craft Mustang, the interior had been redone, and it was just painted, and engine rebuilt (interceptor 165hp), but the engine mounts to the stringers by lag bolts, and where it mounts has rotted quite a bit, and now the bolts are loose.
    I ripped up the floor to get a better look at the main stringers, and they appear to be 2x10 lumber, ( close to 10" in the front of the boat and carved down to about 4" in the rear of the boat). There are also 2 secondary stringers (one to the outside of each main stringer about 12" away). and there is lots of FOAM between the secondary and main stringer. SOOOO here is what I would like to do, and if anyone knows a better way or an EASIER way that would be absolutely great.
    I planned on removing the foam (painstakingly) and get as much of it gone as i can. Then I was going to use a reciprocating saw to saw the stringer off, I was going to leave about 2" of the bottom of the stringer, then I was going to chisel out the remaining wood, leaving a 2" "sleeve" of fiberglass that I could use to put the new stringer in.
    I was going to buy some lumber 2x10, i guess white oak, or fir, i was hoping to use pine (home depot wood) but it looks like thats a bad idea? Then I was going to cut the board to shape as best I could and epoxy the bottom of this sleeve then slide the board into the sleeve and epoxy the whole thing, and then glass over the top and sides back down to the 2" sleeve of glass that I plan on leaving.
    So here are some problems I am having and any help would be great.
    First the ENGINE, it sits on the stringers, but no engine hoist i know of has a boom long enough to get the engine out of the boat, so i was thinking I might be able to detach the driveshaft, and jack the engine up under the engine, and then just replace one stringer at a time, to hopefully give me enough working room. any thoughts? I was also thinking about maybe trying to slide it over, about 6" would be enough i think (its an inboard engine) Any Thoughts????

    Secondly does anyone know of any better way to remove wood then with a chisel as it is probably going to take a long time, as the back 2/3 of the stringer is rotted, but the front section is completely solid (i drilled holes to check).

    Finally can anyone give me a walk through of the process, as they have done it or would do it. Including the materials used, for instance, type of lumber? type of epoxy? glass? also i have heard you are supposed to lay something down between the wood and the hull, is this just epoxy or is it something else?
    Thank you so much for any help you can give me, sorry again for such a long message, ive read tons of posts, but i just want to make sure i am doing this the best way, or to see if there is anything easier i can do, as this is a LARGEEEE project apparently.
    Kevin P.
  2. flydog
    Joined: Oct 2006
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    Location: Atlanta

    flydog Junior Member



    If you have a digital camera, perhaps you could post some photos to better explain your situation. I'm a newbie here, but it sounds like you have a plan that sounds feasable. Pleeeeez be careful working under that engine! Do you plan on using your boat on Lake Jordan? I use to live in Fayetteville, NC.

  3. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    Get the engine out of the boat before you begin the repair job. Find someone with a suitable A- frame hoist or maybe your cousins brother in law has a crane or large front loader. Just find a way. Trying to work around the engine is a handicap that you don't need. A danger as well.

    You might consider sistering the stringers but if there is too much soft wood you'd be better to replace them. Be aware that there is often a lot of oil soaked wood under and near the engine location. If there is the slightest suspicion of oil in the wood, then epoxy would be suspect.

    Try to determine the type of wood that the original stringers are made of. Use the same type for the repair job. Wood swells and shrinks and different woods have different rates of swell/shrink. Disabuse yourself of the notion that Home Depot has anything in the store worthy of installing in or on your boat. They do have some tools that you may find useful. You can rip out a lot of wood with a router for example. A big router is dangerous when guided by hand but a plunge type could be used if caution is maintained. A trim router, though less powerful, is smaller and more manageable. Go to a real lumber yard, or maybe several of them to find the wood what you need without compromise. You will want to use high dollar lumber for motor mounts. Look for quarter sawn, sometimes called vertical grain, wood. You may even have to have it custom milled. Dont economize your engine stringers. Even if Correct Craft used lag screws for original installation I'd try to think of a more reliable fastener system.
  4. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    A chain fall or come-a-long can easily handle the engine in your boat (Chevy 6 cyl.?). Attach it to something stout, like a fat tree branch, yank and drop it in the bed of a pickup so you can take it some place out of the way.

    Unfortunately, there aren't any easy ways to remove rotten wood. I usually don't bother trying to save portions of a stringer on a boat that size or age. The SawsAll (reciprocating saw) can be your best friend here as it removes the damage cleanly and the 'glass pieces can be saved for reinstallation. You'll still end up inside the stringer "channel" with a chisel, grinder and cussing a lot, but the bulk can be removed quickly by hacking out the major portions of stringer with a saw.

    Epoxy brand is mostly a matter of user preference. All the major brands make a good product. Epoxy use is largely a function of using the correct procedures and reinforcement materials (fabrics and fillers). Follow the manufactures recommended instructions, log onto their web sites (for hints and tricks) and maybe practice a little with smaller, less important projects first. Once you get familiar with this goo, it's pretty easy.

    You can use a foam between your stringers and hull, but it's not necessary on your hull. Bed the new stringers (probably mahogany, oak or Douglas fur) in well thickened epoxy and reattach the glass skin. You'll want additional layers of cloth over the stringer to reinforce where you cut it and to seal it up good.

    Ditto Messabout comments on using a better engine mount arrangement. Buy some adjustable mounts that will be permanently fixed to the stringers, but can be turned to adjust shaft angle. It beats using shims, trust me.

    Have you contacted Correct Craft or one of the web sites entertaining them?

  5. kapaduch
    Joined: Feb 2007
    Posts: 2
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    Location: Raleigh, NC

    kapaduch New Member

    Hey Guys,
    Thanks for all the help so far. Well today I finally got the engine out of the boat, used a big crane engine lift from a post on craigslist, so that worked pretty well.
    I also have read up on removing the stringers on lots of forums, so heres my new plan, criticism is welcomed. I am going to do them one at a time to prevent flex. Im going to cut the top of the stringer off (which I just about have one stringer done), then I bought an electric chainsaw today, (another craigslist buy). In the middle of the boat the stringer wood is very soft, I can chisel through it with no difficulty, however in the front 5 feet and rear 2 feet it is very solid, and dry wood, that is nearly impossible to chisel through. So now I have two options, of course I shouldddd replace the whole stringer and not just the damaged portion, but this means I would have to pull the gas tank as well, and to be honest I just can figure out how it is held in. And that also means working in the tiny space below the steering wheel and front of the boat. So..... I know I should replace the whole thing, but the fiberglass is about 1/4" thick all around, and ive read the majority of the strength in these types of hulls comes from the glass not the wood, so heres my plan, I will cut the good wood down at a 45 degree or less angle, then insert my new wood about 6' long, epoxy the bejesus out of it and lay new glass to cap it off again. Any objections??
    Also does anyone know where you can find these adjustable mounts, I was worried about lining the engine up perfectly, and that seems like a great solution.
    kevin P.
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