Hi, I am pretty sure this question has been covered before, but I
thinking now about casting my lead fin keel.
The architects drawings show the keelbolts bent over inside the keel
to lock them in, but I have always been told to draw a keel bolt every
few years to check their condition.

Any thoughts on this? It would be simple enough to fit a frame with
nuts to screw the keelbolts into before pouring the lead around, so
that they stay unscrewble, but is this the best solution?

And is there a better material to use than stainless steel? - Within
reason that is.

The keel weight is 2 tons

Pete

I've been told that for a lead keel, one must use bronze fasteners.

Roger

http://home.insightbb.com/~derbyrm

"pete" wrote in message
news

Hi, I am pretty sure this question has been covered before, but I
thinking now about casting my lead fin keel.
The architects drawings show the keelbolts bent over inside the keel
to lock them in, but I have always been told to draw a keel bolt every
few years to check their condition.

Any thoughts on this? It would be simple enough to fit a frame with
nuts to screw the keelbolts into before pouring the lead around, so
that they stay unscrewble, but is this the best solution?

And is there a better material to use than stainless steel? - Within
reason that is.

The keel weight is 2 tons

Pete

Pete,
The best choice is maleable iron, but finding them is difficult. Find a guy
that makes wrought iron gates. It is best to have them made by a blacksmith.
The second best is manganese bronze. The absolute last material to use is
stainless. The explanation is long and tortuous, but here is a short
version. Stainless is susceptable to crevise corrosion and when it occurs,
it is very fast. Stainless is rust free only in the presence of oxygen. If
the bolt is subjected to rubbing, even a little bit, the oxide coating is
removed and must replentish. When the water around the bolt is oxygen
depleted (stagnent water), the corrosion begins. Iron is non-homogenous and
is not susceptible to internal electrolosis like steel, because steel is an
alloy (homogenous). Bronze is also good, but it is suceptable to dissimilar
metal electrolosis, especially with steel alloys and requires extensive
galvanic protection.(sacrificial anodes) In making your choice, you need to
consider hull material and underwater metal. When using iron, use old
fashion red lead packing for protection outside and tar inside.
Steve

"pete" wrote in message
news

Hi, I am pretty sure this question has been covered before, but I
thinking now about casting my lead fin keel.
The architects drawings show the keelbolts bent over inside the keel
to lock them in, but I have always been told to draw a keel bolt every
few years to check their condition.

Any thoughts on this? It would be simple enough to fit a frame with
nuts to screw the keelbolts into before pouring the lead around, so
that they stay unscrewble, but is this the best solution?

And is there a better material to use than stainless steel? - Within
reason that is.

The keel weight is 2 tons

Pete

Thanks, where I live there are loads of these guys. You have confirmed
what I thought about the stainless problem, but do I need to use
larger diameter iron bolts in lieu of a given diameter for the
stainless ones?

The hull is wood strip composite, so no problems for anything there.

On Tue, 14 Feb 2006 20:24:17 +0100, "Steve Lusardi"
wrote:

Pete,
The best choice is maleable iron, but finding them is difficult. Find a guy
that makes wrought iron gates. It is best to have them made by a blacksmith.
The second best is manganese bronze. The absolute last material to use is
stainless. The explanation is long and tortuous, but here is a short
version. Stainless is susceptable to crevise corrosion and when it occurs,
it is very fast. Stainless is rust free only in the presence of oxygen. If
the bolt is subjected to rubbing, even a little bit, the oxide coating is
removed and must replentish. When the water around the bolt is oxygen
depleted (stagnent water), the corrosion begins. Iron is non-homogenous and
is not susceptible to internal electrolosis like steel, because steel is an
alloy (homogenous). Bronze is also good, but it is suceptable to dissimilar
metal electrolosis, especially with steel alloys and requires extensive
galvanic protection.(sacrificial anodes) In making your choice, you need to
consider hull material and underwater metal. When using iron, use old
fashion red lead packing for protection outside and tar inside.
Steve

"pete" wrote in message
news

Hi, I am pretty sure this question has been covered before, but I
thinking now about casting my lead fin keel.
The architects drawings show the keelbolts bent over inside the keel
to lock them in, but I have always been told to draw a keel bolt every
few years to check their condition.

Any thoughts on this? It would be simple enough to fit a frame with
nuts to screw the keelbolts into before pouring the lead around, so
that they stay unscrewble, but is this the best solution?

And is there a better material to use than stainless steel? - Within
reason that is.

The keel weight is 2 tons

Pete

You will have a very hard time finding malleable iron bolts these days. 99%
of what we call "wrought iron" these days is actually mild steel. You can
find aluminum bronze which is much better but it will cost you more than the
rest of the boat.

Because of all the talk about crevasse corrosion I did a lot of research
before settling on 316 stainless. Crevasse corrosion requires an oxygen
depleted environment AND an electrolyte like seawater. If the hull to keel
joint is reasonably well sealed there will be no electrolyte. Stainless is
a compromise but 99% of production boats are built with stainless keel
bolts. If it were as bad as a lot of people think we would have keels
falling off all over the place.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"pete" wrote in message
...
Thanks, where I live there are loads of these guys. You have confirmed
what I thought about the stainless problem, but do I need to use
larger diameter iron bolts in lieu of a given diameter for the
stainless ones?

The hull is wood strip composite, so no problems for anything there.

On Tue, 14 Feb 2006 20:24:17 +0100, "Steve Lusardi"
wrote:

Pete,
The best choice is maleable iron, but finding them is difficult. Find a
guy
that makes wrought iron gates. It is best to have them made by a
blacksmith.
The second best is manganese bronze. The absolute last material to use is
stainless. The explanation is long and tortuous, but here is a short
version. Stainless is susceptable to crevise corrosion and when it occurs,
it is very fast. Stainless is rust free only in the presence of oxygen. If
the bolt is subjected to rubbing, even a little bit, the oxide coating is
removed and must replentish. When the water around the bolt is oxygen
depleted (stagnent water), the corrosion begins. Iron is non-homogenous
and
is not susceptible to internal electrolosis like steel, because steel is
an
alloy (homogenous). Bronze is also good, but it is suceptable to
dissimilar
metal electrolosis, especially with steel alloys and requires extensive
galvanic protection.(sacrificial anodes) In making your choice, you need
to
consider hull material and underwater metal. When using iron, use old
fashion red lead packing for protection outside and tar inside.
Steve

"pete" wrote in message
news

Hi, I am pretty sure this question has been covered before, but I
thinking now about casting my lead fin keel.
The architects drawings show the keelbolts bent over inside the keel
to lock them in, but I have always been told to draw a keel bolt every
few years to check their condition.

Any thoughts on this? It would be simple enough to fit a frame with
nuts to screw the keelbolts into before pouring the lead around, so
that they stay unscrewble, but is this the best solution?

And is there a better material to use than stainless steel? - Within
reason that is.

The keel weight is 2 tons

Pete

Sorry Glenn, there are keels falling off all over the place. You just don't
hear about them so often. I can think of 2 incidents that were highly
publicized. Simon something-or-other of Bonjovi putzing about the Solent
about 15 years ago in his 75' Maxi and "Plop" right in front of hundreds of
other boaters in Southhampton water he nearly drowns. Then you had that Tony
something-or-other in one of the more recent BOAC challenges off the coast
of Australia. Took an act of God and the Australian Navy to save his ass.

You are correct about having to have both a depleted environment and an
electrolyte, but that is exactly what you have. You are also correct about
sealing, but I don't think it is possible to do. There is simply to much
movement between the hull and the external ballast to give me peace of mind.
All it takes is a little seapage and you have stagnant water just ready to
be depleted of oxygen. Iron is available and it is cheap. It resists fatique
better than stainless and rusts only to a point and stops. Most importantly,
it resists electrolysis because it is non-homogenous and it is proven
solution over a very long time of useage.

I know you believe in what you say. You practise what you preach. You did a
super job on your ballast and I truly wish you success, but the stainless
bolts still trouble me.
Steve

"Glenn Ashmore" wrote in message
news:a9GIf.32633$Dh.4639@dukeread04...
You will have a very hard time finding malleable iron bolts these days.
99% of what we call "wrought iron" these days is actually mild steel. You
can find aluminum bronze which is much better but it will cost you more
than the rest of the boat.

Because of all the talk about crevasse corrosion I did a lot of research
before settling on 316 stainless. Crevasse corrosion requires an oxygen
depleted environment AND an electrolyte like seawater. If the hull to
keel joint is reasonably well sealed there will be no electrolyte.
Stainless is a compromise but 99% of production boats are built with
stainless keel bolts. If it were as bad as a lot of people think we would
have keels falling off all over the place.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"pete" wrote in message
...
Thanks, where I live there are loads of these guys. You have confirmed
what I thought about the stainless problem, but do I need to use
larger diameter iron bolts in lieu of a given diameter for the
stainless ones?

The hull is wood strip composite, so no problems for anything there.

On Tue, 14 Feb 2006 20:24:17 +0100, "Steve Lusardi"
wrote:

Pete,
The best choice is maleable iron, but finding them is difficult. Find a
guy
that makes wrought iron gates. It is best to have them made by a
blacksmith.
The second best is manganese bronze. The absolute last material to use is
stainless. The explanation is long and tortuous, but here is a short
version. Stainless is susceptable to crevise corrosion and when it
occurs,
it is very fast. Stainless is rust free only in the presence of oxygen.
If
the bolt is subjected to rubbing, even a little bit, the oxide coating is
removed and must replentish. When the water around the bolt is oxygen
depleted (stagnent water), the corrosion begins. Iron is non-homogenous
and
is not susceptible to internal electrolosis like steel, because steel is
an
alloy (homogenous). Bronze is also good, but it is suceptable to
dissimilar
metal electrolosis, especially with steel alloys and requires extensive
galvanic protection.(sacrificial anodes) In making your choice, you need
to
consider hull material and underwater metal. When using iron, use old
fashion red lead packing for protection outside and tar inside.
Steve

"pete" wrote in message
news
Hi, I am pretty sure this question has been covered before, but I
thinking now about casting my lead fin keel.
The architects drawings show the keelbolts bent over inside the keel
to lock them in, but I have always been told to draw a keel bolt every
few years to check their condition.

Any thoughts on this? It would be simple enough to fit a frame with
nuts to screw the keelbolts into before pouring the lead around, so
that they stay unscrewble, but is this the best solution?

And is there a better material to use than stainless steel? - Within
reason that is.

The keel weight is 2 tons

Pete

Steve Lusardi wrote:
Simon something-or-other of Bonjovi


Ha ha, that is "Simon Le Bon" from Duran Duran, even. :-)

Ok Steve now lets ignore such things as canting keels, keels on high tech
racing boats which are fourteen feet deep and fastened with minimum strength
to save weight.
Give us a few examples of normal production boats that have lost their
keels.
"Steve Lusardi" wrote in message
...
Sorry Glenn, there are keels falling off all over the place. You just
don't hear about them so often. I can think of 2 incidents that were
highly publicized. Simon something-or-other of Bonjovi putzing about the
Solent about 15 years ago in his 75' Maxi and "Plop" right in front of
hundreds of other boaters in Southhampton water he nearly drowns. Then you
had that Tony something-or-other in one of the more recent BOAC challenges
off the coast of Australia. Took an act of God and the Australian Navy to
save his ass.

You are correct about having to have both a depleted environment and an
electrolyte, but that is exactly what you have. You are also correct about
sealing, but I don't think it is possible to do. There is simply to much
movement between the hull and the external ballast to give me peace of
mind. All it takes is a little seapage and you have stagnant water just
ready to be depleted of oxygen. Iron is available and it is cheap. It
resists fatique better than stainless and rusts only to a point and stops.
Most importantly, it resists electrolysis because it is non-homogenous and
it is proven solution over a very long time of useage.

I know you believe in what you say. You practise what you preach. You did
a super job on your ballast and I truly wish you success, but the
stainless bolts still trouble me.
Steve

"Glenn Ashmore" wrote in message
news:a9GIf.32633$Dh.4639@dukeread04...
You will have a very hard time finding malleable iron bolts these days.
99% of what we call "wrought iron" these days is actually mild steel.
You can find aluminum bronze which is much better but it will cost you
more than the rest of the boat.

Because of all the talk about crevasse corrosion I did a lot of research
before settling on 316 stainless. Crevasse corrosion requires an oxygen
depleted environment AND an electrolyte like seawater. If the hull to
keel joint is reasonably well sealed there will be no electrolyte.
Stainless is a compromise but 99% of production boats are built with
stainless keel bolts. If it were as bad as a lot of people think we
would have keels falling off all over the place.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"pete" wrote in message
...
Thanks, where I live there are loads of these guys. You have confirmed
what I thought about the stainless problem, but do I need to use
larger diameter iron bolts in lieu of a given diameter for the
stainless ones?

The hull is wood strip composite, so no problems for anything there.

On Tue, 14 Feb 2006 20:24:17 +0100, "Steve Lusardi"
wrote:

Pete,
The best choice is maleable iron, but finding them is difficult. Find a
guy
that makes wrought iron gates. It is best to have them made by a
blacksmith.
The second best is manganese bronze. The absolute last material to use
is
stainless. The explanation is long and tortuous, but here is a short
version. Stainless is susceptable to crevise corrosion and when it
occurs,
it is very fast. Stainless is rust free only in the presence of oxygen.
If
the bolt is subjected to rubbing, even a little bit, the oxide coating
is
removed and must replentish. When the water around the bolt is oxygen
depleted (stagnent water), the corrosion begins. Iron is non-homogenous
and
is not susceptible to internal electrolosis like steel, because steel is
an
alloy (homogenous). Bronze is also good, but it is suceptable to
dissimilar
metal electrolosis, especially with steel alloys and requires extensive
galvanic protection.(sacrificial anodes) In making your choice, you need
to
consider hull material and underwater metal. When using iron, use old
fashion red lead packing for protection outside and tar inside.
Steve

"pete" wrote in message
news
Hi, I am pretty sure this question has been covered before, but I
thinking now about casting my lead fin keel.
The architects drawings show the keelbolts bent over inside the keel
to lock them in, but I have always been told to draw a keel bolt every
few years to check their condition.

Any thoughts on this? It would be simple enough to fit a frame with
nuts to screw the keelbolts into before pouring the lead around, so
that they stay unscrewble, but is this the best solution?

And is there a better material to use than stainless steel? - Within
reason that is.

The keel weight is 2 tons

Pete