[Public-List] seacocks: not that hard to install

Randy Katz randyk at bertschi.org
Mon Jul 28 22:03:36 PDT 2008


Greetings,
Funny to see the seacocks notices-- I just switched out 3 more of the
    old through hulls and "seacocks" in my #249 this last weekend. I
    replaced four others last summer-- It's not that hard!
 
JB'S info is correct. The hardest part, I thought, was chipping out
      the original, 40-yr-old through hulls, that wasn't all that
      difficult or time consuming. (Reaching the cockpit drain
      fittings via lazarette can be tough. The panel I cut (about 1 x
      1 ft. inside the prt lazarette in order to reach the
      transmission and exhast system made it possible. The drain on
      stbd. was not accessible this year-- I have to cut a panel on
      that side for next summer-- or pull the engine!) By originals I
      mean thin through hulls held in place by old, crumbly caulking
      (scary!). A couple of the older t-hulls were corroding and were
      really on their last legs. Backing for the originals was one or
      two 5" squares of 1/4" plywood. A couple backings were ply plus
      a round 1/4" thick FG circle which seemed to provide a
      relatively dressy cover plate right under the "seacock."

I replaced them with new t-hull fittings (got the ones with a cupped
     edge for holding the 3M 5200 caulk (permanent) which I understand
     to be the customary goop to use these days. New Apollo seacocks
     (I needed a few 1" ones-- bronze, yellow handle, base with screw
     holes for attaching to or through the backing board) are $100 new
     at West Marine. I found one at the Bellingham, WA. used marine
     store (Pacific Marine, a great place) in perfect condition (but
     with no handle) for $20.

The "special wrench" that is needed by your helper on the outside of
    the hull (they hold the t-hull stationary while I screw the
    seacock on from the inside-- after trimming the t-hull to the
    correct length, a must-do job) can be made from any scrap metal.
    The 3/8" alum. plate cut-off from my mast beam plate happens to be
    perfect. It's four inches wide in the middle tapering to a point
    on each end, one of which I truncated to about .5" width-- works
    like a charm.

The recommendation is to secure the seacock base through the hull
    using bolts from the outside that run through the three holes in
    the cock's base -- I'm content to avoid adding more holes in the
    bottom and to screw the base firmly to the backing plate upon
    which the seacock sits. (3/4" ply, glassed into place using West
    System epoxy as per directions with 406 thickener-- follow the
    directions, very easy! (Be sure to use protective respirator and
    clothing-- that's deadly stuff). If you were doing things really
    up to snuff, and probably to ABYA (?) standards and/or for ocean
    travel you'd want to take this extra step.

I recall that people trying to remove newer t-hulls that were
      installed with 5200 have a harder challenge due to the
      difficulty of that substance: apparently heat is a big help in
      removing it. I'm expecting to never have to deal with this job
      again in my lifetime.

I encourage people to have a go at this yourself. I have some other
     tips if you're interested. I believe any of use would do a more
     careful job than most boatyard employees in as much as we REALLY
     care about doing a good job.

I have many photos, too, which I'm glad to share with those
    interested.

  Regards,
Randy Katz
#249
Bellingham/Seattle, WA.

    
> Today's Topics:
> 
>    1. seacocks (J Bergquist)
>    2. Re: seacocks (Roger L. Kingsland)
> 
> 
>
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Mon, 28 Jul 2008 12:00:49 -0400
> From: "J Bergquist" <jbergqui at gmail.com>
> Subject: [Public-List] seacocks
> To: "Alberg 30 Public List -- open to all"
> 	<public-list at lists.alberg30.org>
> Message-ID:
> 	<bef708940807280900i2e12a5f1oc81bc90d75f50eea at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> There is a really great article about seacocks in the current issue
> of
> Professional Boatbuilder magazine. You can find a digital copy of
> the
> magazine (for free!) at:
> 
> http://www.proboat-digital.com/proboat/20080809/
> 
> I thought I knew something about seacocks. What I learned by reading
> this article is that all of the seacocks in my boat are improper,
> which made me think 2 things:
> 
> 1. I should probably change them before too long.
> 
> 2. They have lasted a long time as is. So maybe it's not the first
> thing that I should do, and it does seem like it would be quite a
> job.
> 
> I am sure many folks reading this list already know the proper
> seacock
> installation ABYC specification, but it was news to me so I assume
> there are others out there who also didn't realize it. Basically,
> what
> I learned is that bronze thru-hulls have straight NPS (not NPT)
> threads on them, which means if you screw a standard ball valve
> (which
> normally has NPT threads), only a few threads will register before
> you
> hit the taper. In reality, thru hulls are supposed to be screwed
> into
> a seacock that has matching NPS threads from the outside. The
> seacock
> gets pre-installed with lag screws so that it is fixed and you use a
> special wrench to turn the thru-hull into the seacock itself from
> outside the boat. This process is illustrated and explained in the
> article.
> 
> Anyway, what I have is standard ball valves with NPT threads screwed
> onto the ends of my thru-hulls. This is basically exactly wrong. I
> had
> no idea. Apparently it is a common mistake made by do-it-yourselfers
> and even some professionals. I thought my installations were correct
> because they were ball valves instead of gate valves. But the proper
> ABYC-compliant installation should have actual seacocks lag screwed
> to
> the backing block and with the thru hull threaded all the way in
> from
> the outside.
> 
> I just thought there might be other folks out there who would find
> this article interesting.
> 
> There is also a sweet article about fiber orientation and lamination
> defects which is pretty cool.
> 
> Later,
> 
> J Bergquist
> 
> 
> ------------------------------
> 
> Message: 2
> Date: Mon, 28 Jul 2008 17:00:40 -0400
> From: "Roger L. Kingsland" <r.kingsland at ksba.com>
> Subject: Re: [Public-List] seacocks
> To: "'Alberg 30 Public List -- open to all'"
> 	<public-list at lists.alberg30.org>
> Message-ID: <00ba01c8f0f4$ff9b3f70$af00a8c0 at office.ksba>
> Content-Type: text/plain;	charset="iso-8859-1"
> 
> J,
> 
> I certainly was interested when you mentioned an article on
> seacocks, but
> when you also mentioned fiber orientation and lamination defects;
> wow, were
> talking goose bumps at this end of cyber space! Seriously, thanks
> for
> keeping us up to date. I need seacocks and can now do a better job
> of it.
> 
> All the best,
> 
> Roger
> 
> PS - does anyone know the sell price of the A30 that was on eBay. It
> had
> sold before I logged on (for that matter, is there any way to
> research sold
> items on eBay)    
> 




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