[C38] Thru-hull fittings

[les]

On Knee Deep (formerly JACE), we found that the thru-hulls were leaking
at the joint between the fiberglass mound and the threaded nipple.  I
opted to replace all the thru-hulls with traditional bronze thruhulls
and new valves.  I did not attempt this job myself, and had it done in
San Diego at Oceanside Marine Center.  If you race, you would want the
flush designs, but I wanted maximum strength, so I chose the button
style.  This was some time ago, so the price would not be relevant
today, but it was about $1200 8 years ago.

There are some various kinds of thru-hulls of plastic, infused glass and
some newer stuff.  Be very careful, some of these are not rated for
below the waterline use.  Every thruhull on the CAT-38 spends some time
below the waterline when cruising or racing hard, so I just wouldn't
trust the ones not rated for that.

Les H.

On Wed, 2013-05-08 at 02:40 -1000, Jon Whitney wrote:
> Hi All,
> 
> I'm preparing for my first haul-out since buying our 1979 C38 a couple
> years ago and am seeking some advice on re-doing our thru-hulls.  All
> 4 of the current thru-hulls (head intake, sewage out, galley sink out,
> and engine intake) are all configured with in-line ball valves
> threaded directly onto the thru-hull fittings (i.e., no seacocks) and
> mismatched thread sizes (NPS on thru-hull to NPT valves). All 4 are
> badly corroded (presumably due to non-marine rated valves). 
> 
> From what I can tell (measuring them in place) the thru-hulls sizes
> are as follows:
> Head intake (under vberth): 1/2" NPS
> Galley sink out (under galley sink): 1/2" NPS
> Engine intake: 1/2" NPS
> Head/sewage out: 1 1/4" NPS
> 
> Are these sizes consistent on other hulls? They don't all match what
> my blueprints say (e.g., galley sink out and sewage out are listed as
> 3/4" NPS) 
> 
> I am wondering what others have done when replacing their thru-hulls.
> I would like to install proper flanged seacocks for each one, but am
> having trouble finding flanged seacocks for 1/2" NPS thru-hulls (none
> of the manufacturers I have looked at carry them, e.g., Groco, Apollo,
> Buck Algonquin). I'm curious if others have run into this issue and
> what solutions you have found. If I can't find 1/2" seacocks, then
> have others resized the thru-hulls to 3/4" so I can fit them with the
> proper hardware? Should the engine intake be 3/4" anyway?  For obvious
> reasons I would like to avoid having to have to re-drill thru hulls to
> up the size, but am looking for best options.  
> 
> Any help or suggestions would be greatly appreciated. Thanks in
> advance for any advice.
> 
> Best,
> Jon Whitney
> "Eye Whitness"
> 1979, Hull 54
> Honolulu 
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