Help! Hole above the forepeak!

Discussion in 'Boatbuilding' started by steelsunrise, May 25, 2014.

  1. steelsunrise
    Joined: May 2014
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    steelsunrise New Member

    While doing some light cleaning with a wet vac, I accidentally created a small hole in the deck. The epoxy coating was already cracking, and the area is where I (foolishly) often smashed down heavy fuel jugs.

    [​IMG]

    Obviously, I need to repair it, asap. I have some west marine epoxy, and some fiberglass matt. I was thinking that I'd do a little bit of light grinding, then clamp a 4"x4" section of plywood from the bottom, and then apply the epoxy-saturated matt to the top.

    [​IMG]

    The thing is, the whole deck is in pretty serious need of repair, but I'm not in a financial place where I can get it hauled out. Here's a longer shot:

    [​IMG]

    My question is: what is the best thing for me to do RIGHT NOW... (i.e., today and tomorrow) and what should I intend on doing? Because of EPA regulations, I don't think I can do any sandblasting where she sits right now. Should I consider grinding/wirebrushing the whole thing this week, and then paint it?

    Thanks so much, folks!
     
  2. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member

    various emergency patches can be installed. Epoxy putty like the old technologies, Redhand or Splash Zone A-788 is carried on most commercial steel vessels for temporary repairs. But there are NEWER BETTER products. See Link.

    http://www.epoxyproducts.com/under4u.html

    however IMHO, the nearest thing to a super GOO for steel repair is good old Portland Cement. Clean the paint off the area of deck needing repair, as best you can with electric wire brush. You'll find more holes probably. Tack weld expanded steel mesh to the deck over the repair area. More tacks the better. Doesn't have to be expert welding. "Gorilla" weld is okay. (novice, ugly, welding) Mix a thick slurry of Portland cement and water, (I mix with my hand in 5 gal bucket), and add some 2 part epoxy paint if you have any, freshly mixed up. Doesn't matter what brand or color. The epoxy makes a harder better bonded cement patch. Don't have epoxy?, then latex helps bonding. Neither is required. Trowel the cement into the expanded mesh you welded over deck. and a build half inch surface coat above mesh. Later when nearly set, you can broom it with a stiff bristle brush for a nonskid surface. Paint the cured patch with epoxy paint, if you have any. Or paint with ROAD MARKING paint, if you have a friend in highway dept. Or just leave it natural and ugly green/grey.

    This makes a TEMPORARY repair, that will last quite awhile if needed to, and will seal and strengthen your steel deck. But it's STILL just a temporary patch. Unless you have a ferrocement boat, which is made this way.

    Cement becomes as strong as steel in close proximity to steel. That's what reinforced concrete is all about. In addition cement EXPANDS as it cures. A rather unusual aspect since most things SHRINK as they harden. Anyway, the price is right. Cement is CHEAP.
     
  3. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    Steel in reinforced concrete does not make cement as strong as steel. It adds tensile strength to concrete.

    That cement expands when it cures is not true. How could a brick wall ever be constructed without it self destructing?


    If a vacuum cleaner sucked that big of a hole in the deck, you've got serious problems. The corrosion is coming from below, that chipped area about 6" to the right is ready to do the same thing. For a quick patch, you could steel brush the area, wipe it clean with some solvent and screw down some 1/16 -1/8" steel with self taping screws. Bed the steel in something to keep out the water. Throw one of those mats over it if it seems it might be a trip hazard.
     
  4. Yobarnacle
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    Yobarnacle Senior Member

    We always carry expansive cement on board. My error was thinking this was normal Portland cement.


    http://www.wisegeek.com/what-is-hydraulic-cement.htm

    "One common application for special hydraulic cement blends is repairing cracks and leaks. Certain types of cement contain an ingredient which causes the cement to expand as it sets, filling in leaks and holes in concrete or other structural materials. There is often a need for this type of repair work because of the fact that ordinary Portland cement shrinks slightly as it dries. Places like basements in areas with wet climates are especially prone to leaks because of this. These special blends can be hard for novices to work with, though, because once mixed, the material only remains workable for 10 to 15 minutes."

    http://www.concrete.org/TopicsinConcrete/TopicDetail.aspx?id=34&Search=Expansive Cement

    Read about self stressing concrete. in above.



    http://www.i4at.org/surv/ferro.htm

    "Cement is the strongest when it is less than one-forth of an inch away from steel reinforcing. In ferro-cement, the overlapped chicken wire is the reinforcing, and all of this wire is what gives it its great strength and ability to withstand stress. By having several layers of chicken wire, with the cement being forced to fill in all the spaces, a very strong cement structure is the result."


    http://www.permies.com/t/5298/green-building/Ferro-Cement

    "with good design ferrocement can be nearly equal in strength to steel plate in comparitive thicknesses"
     
  5. SamSam
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    SamSam Senior Member

    Hydraulic cement looks handy. I might have known about hydraulic cement and then forgotten about it. Like in the Gary Larson cartoon, "May I be excused, my brain is full." I'm thinking there is not much deck to attach to, it looks to be pretty rotten, at least around the hatch. I guess if he put a fairly large cement patch over the area to spread the load, it would work fine.

    Those last two links are more or less unfounded claims on DIY sites, so I'm not believing the quotes attached to them.
     
  6. Yobarnacle
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    Yobarnacle Senior Member

    "Hydraulic" cement means you mix it with water. The EXPANSIVE types of hydraulic cement are what we use for emergency patches on ships, barges, engines, piping, ect.

    While there is much technical information about reinforced concrete (rebar ect), I can find very little real technical data about ferrocement. Lots of opinions, but no lab tests.

    The US govt lamented lack of hard data in these documents.

    http://pdf.usaid.gov/pdf_docs/PNAAA595.pdf

    http://pdf.usaid.gov/pdf_docs/PNABC985.pdf

    relying on "expert opinion" and recommending formal analysis. These are from 1973!

    It's what you find when you search for ferrocement property analysis.

    Has there been no engineering analysis in the 50 years since these publications?

    I can't find any.

    So opinions are what we got. MY opinion? The stuff WORKS!

    I've temporarily repaired decks, piping, engine blocks, underwater hull leaks, head rakes on barges, ect, ect.

    Its nearest thing to SUPER GOO I know of. We use expanded steel mesh, not chicken wire, for the reinforcement armature. strong enough to walk on, deformes to compound curves by hammering, much lighter than steel plate, when you need to hold it up by hand to get the first weld tacks. And it forms a dense matrix in the cement.
    Cement changes when you mix things like sand (silica) in it. Different chemical process occurs. Same with dense steel/cement mixture. Ferrocement.

    Good luck, Steelsunrise.
     
  7. steelsunrise
    Joined: May 2014
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    steelsunrise New Member

    Update!

    I went with a *REALLY* temporary fix. Try not to laugh:

    [​IMG]

    I used Hot Glue and Shoe Goo to tack down rubber matt around the hole, and then more Shoe Goo around the edges to create a waterproof, flexible seal. I cut a slit in the the rubber to pass an extension cord through to power a small dehumidifier. It turned out there was some rain water in the bilge, so at least I'm making the hole work for me -- the only previous access into the compartment is through the 2' hatch.

    [​IMG]

    Finally, I put a waterproof matt over it, just to give it some protection from the elements and from things snagging on it.

    [​IMG]

    As far as quick fixes go, I think this is probably as far as you can get from 'best practices'. I decided not to go with a more permanent fix because frankly the whole deck needs fixing, as well as other areas on the boat. It just needs to come out of the water, soon.

    Question: do you think this kind of fix will more or less last until August? Even if that's impossible to know, I want to come online again just to post a follow up and thank you all for the advice -- advice I'll probably follow in a few months.

    Thank you again folks. What a community you've created here...
     
  8. Yobarnacle
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    Yobarnacle Senior Member

    Staying in port? Staying aboard?
    Not a suitable patch for ocean voyaging or leaving unattended.
    But as long as you keep an eye on it and stay in sheltered waters, should be fine.

    The secret to remaining afloat is: prevent water from leaking in faster than it can be pumped out. :D
     
  9. Nick.K
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    Nick.K Senior Member

    Learning basic welding with an inverter stick welder is surprisingly easy, you would be able to do good enough welds to weld on a bit of plate over the top of the hole after perhaps a couple of days of practice and some pointers as to the prep and type of rods etc. I´m not recommending this as the best repair but it beats stick-on rubber by a long way and probably wouldn't take much longer to do. After a while you'll be amazed at how quick it is to cut out bits and replace them.
     
  10. Yobarnacle
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    Yobarnacle Senior Member

    Nick K is correct. Welding is an important and necessary skill aboard steel vessels.
    Small ittybitty patches are a nono.
    ABS requires minimum size for an insert, 12 inches by 16 inches.
    Insures you are welding to good steel. The perimeter of 12x16 is 56 inches. If a half inch was weak in a few places, a small % of the total weld.
    A 2x2 patch might not hold, if it was weak a half inch here and there. :)
    I know you aren't ABS classed. But their guidelines are for good reasons. Follow them if you can.
     
  11. Nick.K
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    Nick.K Senior Member

    I wasn't thinking of structural repairs or hull repairs...might need more than a couple of days of practice for that! http://www.boatdesign.net/forums/images/smilies/biggrin.gifJust saying that a welded doubler on the deck is about as easy as any other temporary repair but far more effective..

    Small patches are a no-no because of weld tensions rather than ensuring the surrounding area is good?
     

  12. Yobarnacle
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    Yobarnacle Senior Member

    all the above. correct
     
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