Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

Thanks, Norm B

On Wed, 22 Sep 2004 12:10:21 -0700, engsol
wrote:

Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

I have used three variations on this theme, depending on where on the
curve of the bilges I've needed to "degate" something properly.

1) Simplest: Use simple bedding material, but of course make it 5200
or something equally tenacious. Drill up through the block/ring from
the outside, bed, screw, tighten, wait for cure, tighten a bit more.

2) Make a radiused ring by drawing a chord of the area and sanding it
on a bench grinder or belt until it matches. Bed as before or glass
in.

3) This is the one I thought was clever of me G. Make a wood ring
pad of desired thickness. Using a fine blade on a band saw, cut into
fine "slices" (how fine depends on the wood type). Steam slices into
desired curve. Laminate together with epoxy and glass into place.
Guaranteed not to rot, either, if you use the "epoxy plug" method
mentioned lately for deck core isolation.

My .02 and congratulatations on your new old vessel.

R.

engsol wrote:
Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Yep. I did that too.


Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

Why wood? It makes far more sense to me to build up a pad of fiberglass
& resin with some filler. This produces a strong, faired,
non-water-trapping non-dirt-trapping block. Also, it will not split or rot.


The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

Make a template using a couple of pieces of cardboard.


rhys wrote:
I have used three variations on this theme, depending on where on the
curve of the bilges I've needed to "degate" something properly.

1) Simplest: Use simple bedding material, but of course make it 5200
or something equally tenacious. Drill up through the block/ring from
the outside, bed, screw, tighten, wait for cure, tighten a bit more.

The problem with this method is that the contact pressure between the
hull & the valve will be uneven. It may also distort the valve body. It
does not distribute the load, if any, from the valve & piping over an
area of the hull.


2) Make a radiused ring by drawing a chord of the area and sanding it
on a bench grinder or belt until it matches. Bed as before or glass
in.

That works. You can use a Dremel tool, too, although it takes longer.



3) This is the one I thought was clever of me G. Make a wood ring
pad of desired thickness. Using a fine blade on a band saw, cut into
fine "slices" (how fine depends on the wood type). Steam slices into
desired curve. Laminate together with epoxy and glass into place.
Guaranteed not to rot, either, if you use the "epoxy plug" method
mentioned lately for deck core isolation.

Shucks, you didn't start soon enough. It's a good way to build a whole
boat


My .02 and congratulatations on your new old vessel.

My congratulations also.

Fresh Breezes- Doug King

You could try an epoxy pour similar to this:
http://forum.cruisingworld.com/forum...pl?read=381390

Paul
www.jcruiser.org
"engsol" wrote in message
...
Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

Thanks, Norm B

"engsol" writes:

Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Yep, you sure do.

Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

IMHO, forget the wood, here are a couple of alternatives.

1) Substitute standard gray filled PVC plastic for the wood, then bond to
the hull with epoxy based filler, covered with knitted glass.

(Find an industrial plastics distributor in your area and get a remnant
piece of 3/4" PVC.)

Use knitted glass and epoxy to lay up a pad for the seacock.

You don't have to be fussy about the weave since this is basically a
compression load.

Use odd ball scraps if you have any like I do.

The process will take several days since you will only be able to lay a
couple of layers of glass at a time, then wait at least 24 hours before
laying more glass.


HTH

Have fun.

Lew

say, you are now the lou hodgekins disease known are and wide in Brad
Richshaw's GalacticCrusingList, are you? The Low "IQ" HodgekinsDisease clown
who in frickin sists that a 1/4" of fiberglass either side of 1" foam will
"stop a copper-jacketed .357 round at 20 feet" fired by a 17 year old pirate in
a loin cloth?

I was afraid you or brad died standing behind that dumb sandwich as a bullet
was fired.

good to hear you are still alive. how is brad?

From: "Lew Hodgett"
Date: 9/22/2004 10:43 PM Eastern Daylight Time
Message-id:


"engsol" writes:

Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Yep, you sure do.

Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

IMHO, forget the wood, here are a couple of alternatives.

1) Substitute standard gray filled PVC plastic for the wood, then bond to
the hull with epoxy based filler, covered with knitted glass.

(Find an industrial plastics distributor in your area and get a remnant
piece of 3/4" PVC.)

Use knitted glass and epoxy to lay up a pad for the seacock.

You don't have to be fussy about the weave since this is basically a
compression load.

Use odd ball scraps if you have any like I do.

The process will take several days since you will only be able to lay a
couple of layers of glass at a time, then wait at least 24 hours before
laying more glass.


HTH

Have fun.

Lew

On Wed, 22 Sep 2004 12:10:21 -0700, engsol
wrote:

Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

Thanks, Norm B


You could contact cement a sheet of 50 grit sandpaper to the inside of
the hull where the seacock will go. Then just rub the wood block back
and forth till it fits the curve of the hull.
It will be rough but bedding compount will get a better grip on it.
Or switch to finer sandpaper but that really isn't necessary.
Mark E. Williams

Mark,
Thanks for the input. Not a bad idea, except that it requires
that the hull in that section have a constant radius. Agree?
Norm B

On Thu, 23 Sep 2004 03:07:42 -0500, Maynard G. Krebbs wrote:

On Wed, 22 Sep 2004 12:10:21 -0700, engsol
wrote:

Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

Thanks, Norm B


You could contact cement a sheet of 50 grit sandpaper to the inside of
the hull where the seacock will go. Then just rub the wood block back
and forth till it fits the curve of the hull.
It will be rough but bedding compount will get a better grip on it.
Or switch to finer sandpaper but that really isn't necessary.
Mark E. Williams

I used Starboard on all mine. Never have to worry about rot. It's flexible
enough that between the bolting and bedding (I used polysulfide, Boatlife)
it'll be fine. I also prefer Groco seacocks. Expensive, but you get what you
pay for!

--


Keith
__
'I hate quotations.' -- Ralph Waldo Emerson
"engsol" wrote in message
...
Now that I have a boat, I need to replace a couple of
gate valves used as seacocks.

Nigel Calder et all recommend using a wood block and bronze
bolts to secure the seacock to the hull, rather then simply
screwing it to the through hull. Makes sense to me.

The diagrams all show a perfectly flat hull, but as we all know,
real hulls are generally curved. My question is: what's the
best way to contour the wood block (actually a ring) to conform
to the hull? Any hints?

Thanks, Norm B

On Thu, 23 Sep 2004 20:05:20 -0700, engsol
wrote:

Mark,
Thanks for the input. Not a bad idea, except that it requires
that the hull in that section have a constant radius. Agree?
Norm

Not always. You don't have to move the wood block very far back and
forth.
Generally though, I agree.
Mark E. Williams

You could contact cement a sheet of 50 grit sandpaper to the inside of
the hull where the seacock will go. Then just rub the wood block back
and forth till it fits the curve of the hull.
It will be rough but bedding compount will get a better grip on it.
Or switch to finer sandpaper but that really isn't necessary.
Mark E. Williams