Conference unifix::sailing

    Go right ahead and fill them with an epoxy well thickened with
    microballoons. These supplies are now available from places like
    Jamestown Distributors. Thicken to about the consistency of peanut
    butter, and trowel in and strike off smooth with a putty knife or
    equivalent (the throw-away plastic ones are good). Allow to FULLY
    CURE (4-6 DAYS), then sand with 100 grit sandpaper, preferably in
    a power sander. If you have a messy job with a lot of fairing required,
    use a Stanley surform.
    
    It's true that epoxy is quite hard (harder than wood or paint),
    but it's by no means impossible. I would be very careful how I applied
    expoxy to repair wood or fiberglass hulls, because it's easy to
    get dips on either side of a patch because sanding can easily eat
    away more of the softer material. But iron?! no problem!
    
    Ross Faneuf
    

    
    What are microballoons, and what is a surform?
    
       - Jim
    

    Microballoons look like a fine reddish powder. They are in fact
    tiny hollow spheres created by a mysterious industrial process (they
    are some kind of plastic/hydrocarbon). They are used as a filler
    or thickening agent for epoxy because they are relatively cheap,
    non-toxic, and low density.
    
    A Stanly surform is in fact an abomination. It is a tool which purports
    to replace a hand plane, and is available in any hardware store.
    It come in several forms, but all consist of a light metal frame
    with one or two handles, and a bottom composed of a cutter formed
    out of a thin, hardened metal sheet with many small cutting teeth
    formed in it. It is really a form of rasp. Stanley sells it as a
    woodworking tool. It main virtue is that it requires no adjustments
    or sharpening whatsoever, as hand planes do. It produces a very
    poor surface in wood (or anything else, really), consisting essentially
    of a lot of score marks. It has its virtues, however, and as a rough
    forming tool for epoxy, hard foam, or fibreglass it is excellent.
    I use them extensively for removing large gobs and dits of epoxy,
    before tackling them with any tools which leave a better surface.
    
    Ross Faneuf
    

    I just finished redoing the bottom of my boat including filling
    a sizeable chunk of the keel.  I did this using an interlux
    epoxy with microballoons (it's a two part kit, numbers I fail to
    remember but it is not the 417/418 - that is too thin for deep gouges).
    Anyway, the stuff I got was a bit old but I was able to make a thick
    wad of it and formed the after tip of the keel (around a stainless
    screw that I had put in to  help hold the goo).  I let it cure for
    a week and it sanded easily.  I used the 417/418 on the rest of
    the keel to fill the less severe irregularities and that too was
    real easy to sand.  
    
    It is important to prepare the surface first.  I sanded my entire keel 
    to shiny metal then put on interlux 2000/2001 since I was planning to 
    apply that to the entire hull, there is some other compound to use on
    steel.  You may want to call interlux at 800-intrlux.  They will
    send you all the literature you need and are very helpful in answering
    questions.  They sent me a booklet that has step by step directions
    for using their products on everything from steel keels to fibreglass
    hulls.
    
    Pam

    Pam,
    
    Are you sure that the 2000/2001 will bond properly to the lead keel?
    A couple of years back when I used Interprotect on my 34' I *thought*
    that Interlux suggested using the 404/414 Epoxy Barrier Cote on
    the keel.
    
    Or maybe it's just that the 404/414 is much thicker and a better
    filler for the minor scratches and pock marks left after grinding
    down the lead?
    
    For anyone who happens to use the 404/414, be careful not to apply
    it in thick coats. While sanding for adhesive purposes is pretty
    easy, getting rid of sags and runs is not. Better to use two or
    three thin coats and a roller for best results.

    John_R

    My experience is with construction epoxies like Gougeon and System
    3. These products are specifically designed for use as adhesives,
    fillers, etc. Epoxy barrier coat products may have different
    properties, and may not behave/adhere well when used as fillers.
    It might be prudent to buy a small amount  of constructor epoxy
    from someone like Jamestown distributors (or anyone who stocks Gougeon
    rather than use a barrier coat product as a filler.
    
    FWIW, careful cleaning and mixing of epoxies is most important to
    get good results. Grind out and clean your cavities as well as you
    can manage; if possible, borrow a die grinder or something like
    it to grind the interior of these lesions down to clean metal as
    much as possible. Be REAL SURE to thoroughly mix the epoxy; a common
    cause of adhesion problems is insufficiently mixed epoxy. Mix it
    thoroughly BEFORE adding any fillers/thickeners; it's very hard
    to mix properly if you throw everything together and try to mix
    the mass.
    
    Epoxies will absorb a surprising amount of filler. You will find
    that to achieve a peanut butter consistency you will approximately
    triple the volume of epoxy. Just go right ahead, it'll work fine.
    
    Ross Faneuf
    

    I have used the barrier coat from International on both bare metal
    and over prime wash.  I recommend using the prime wash before anything,
    including fillers against the bare lead (or faired bronze thru hull
    fittings).  The fillers and coatings do not adhere to the bare metal
    at all. If the metal is smooth, the coating will flake off in one
    season. Fillers may hold longer because they are usually trowelled
    into a rough surface, byt they may pull away too after only one
    season.  The prime wash is very effective. I havent had a place
    fail at all after coating the metal with the prime wash before fairing
    and sealing.
    
    Walt