To bond or not to bond... that is the question

To bond or not to bond... that is the question

Post by Keit » Wed, 27 Nov 2002 10:38:19


OK. Doing a peel job now, all thru-hulls out. Once they're back in, I'm
installing 7 bronze Groco strainers over mushroom thru-hulls. The
thru-hulls are all bonded. I am wondering if I should bond the strainers
as well, by putting a long machine***through the hull and attaching
them to the bonding system, or just use short screws to affix them to
the hull. They wouldn't touch the mushroom thru-hulls. My guess is that
they wouldn't suffer much if I didn't bond them, but asking for
opinions/suggestions. Using silicon bronze screws to attach them to the
hull.
--
__________________
Keith
"Application denied.  One cannot fertilize with flatus."
    -Abraham Lincoln, on rejecting homeopathic medications for the
                 dispensary of the US troops.
 
 
 

To bond or not to bond... that is the question

Post by Jere Lul » Wed, 27 Nov 2002 16:04:57

Quote:

>OK. Doing a peel job now, all thru-hulls out. Once they're back in, I'm
>installing 7 bronze Groco strainers over mushroom thru-hulls. The
>thru-hulls are all bonded. I am wondering if I should bond the strainers
>as well, by putting a long machine***through the hull and attaching
>them to the bonding system, or just use short screws to affix them to
>the hull. They wouldn't touch the mushroom thru-hulls. My guess is that
>they wouldn't suffer much if I didn't bond them, but asking for
>opinions/suggestions. Using silicon bronze screws to attach them to the
>hull.

7 Grocos! That sounds like overkill -- most only put them on the fresh
water cooling, saving  money by using cheap filters for the inlets that
don't get that sort of volume flow -- or do you have 7 cooling circuits?

If the filters are above the standing waterline (as they should be),
there's no need to bond. If below, it's a personal decision. Even the
AYBC is split between bonding or isolating through hulls. In many cases,
bonding makes it possible to lose them through electrolysis or lightning
strike; leaving them isolated submits them to only normal corrosion

Personally, I've chosen to isolate all our through hulls. Even our shaft
is electrically isolated by the drive-saver. (but the stainless shaft
and bronze prop still "argue" -- we lose half a zinc each season.)

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://SportToday.org/
Our BVI FAQs (290+ pics) http://SportToday.org/

 
 
 

To bond or not to bond... that is the question

Post by Keit » Wed, 27 Nov 2002 20:55:10

These are all strainers below the waterline outside the hull. They cover
mushroom thru-hulls that are bonded, but won't touch them. Two head
intakes, one A/C, one SW washdown pump, ME, genset, reefer. They are
different types, based on flow rates. All bronze, will be affixed to a
fiberglass hull with bronze screws.

Quote:


> >OK. Doing a peel job now, all thru-hulls out. Once they're back in, I'm
> >installing 7 bronze Groco strainers over mushroom thru-hulls. The
> >thru-hulls are all bonded. I am wondering if I should bond the strainers
> >as well, by putting a long machine***through the hull and attaching
> >them to the bonding system, or just use short screws to affix them to
> >the hull. They wouldn't touch the mushroom thru-hulls. My guess is that
> >they wouldn't suffer much if I didn't bond them, but asking for
> >opinions/suggestions. Using silicon bronze screws to attach them to the
> >hull.

> 7 Grocos! That sounds like overkill -- most only put them on the fresh
> water cooling, saving  money by using cheap filters for the inlets that
> don't get that sort of volume flow -- or do you have 7 cooling circuits?

> If the filters are above the standing waterline (as they should be),
> there's no need to bond. If below, it's a personal decision. Even the
> AYBC is split between bonding or isolating through hulls. In many cases,
> bonding makes it possible to lose them through electrolysis or lightning
> strike; leaving them isolated submits them to only normal corrosion

> Personally, I've chosen to isolate all our through hulls. Even our shaft
> is electrically isolated by the drive-saver. (but the stainless shaft
> and bronze prop still "argue" -- we lose half a zinc each season.)

> --
> Jere Lull
> Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
> Xan's Pages: http://SportToday.org/
> Our BVI FAQs (290+ pics) http://SportToday.org/

--
__________________
Keith
Karate is a form of martial arts in which people who have had years and
years of training can, using only their hands and feet, make some of the
worst movies in
the history of the world.
        -- Dave Barry

 
 
 

To bond or not to bond... that is the question

Post by Jere Lul » Thu, 28 Nov 2002 09:09:30

Quote:



>>>OK. Doing a peel job now, all thru-hulls out. Once they're back in, I'm
>>>installing 7 bronze Groco strainers over mushroom thru-hulls. The
>>>thru-hulls are all bonded. I am wondering if I should bond the strainers
>>>as well, by putting a long machine***through the hull and attaching
>>>them to the bonding system, or just use short screws to affix them to
>>>the hull. They wouldn't touch the mushroom thru-hulls. My guess is that
>>>they wouldn't suffer much if I didn't bond them, but asking for
>>>opinions/suggestions. Using silicon bronze screws to attach them to the
>>>hull.

>>7 Grocos! That sounds like overkill -- most only put them on the fresh
>>water cooling, saving  money by using cheap filters for the inlets that
>>don't get that sort of volume flow -- or do you have 7 cooling circuits?

>>If the filters are above the standing waterline (as they should be),
>>there's no need to bond. If below, it's a personal decision. Even the
>>AYBC is split between bonding or isolating through hulls. In many cases,
>>bonding makes it possible to lose them through electrolysis or lightning
>>strike; leaving them isolated submits them to only normal corrosion


>  These are all strainers below the waterline outside the hull. They cover
>mushroom thru-hulls that are bonded, but won't touch them. Two head
>intakes, one A/C, one SW washdown pump, ME, genset, reefer. They are
>different types, based on flow rates. All bronze, will be affixed to a
>fiberglass hull with bronze screws.

Oops! I forgot Grocco had something other than the basket strainers.

If they don't touch any other metal, I'd probably leave them unbonded.
If they DO touch dissimilar metal, it'll probably be the through hull,
so will have the same bonding.

The only exception I could think of would be where through-bolts/screws
stand in bilge water with a bilge pump or switch that could short and
"electrify" the water. Probably would consider screws that don't go
through, but are between standing bilge water and "outside" as needing
bonding. Who knows what currents the screws could conduct in that case.
I wouldn't be worried about the strainers as much as the screws. If the
strainer falls off, the boat won't sink. If a***disintegrates,
that's a possible hole through the hull.

(Personally, I like flush through hulls with inside strainers. They're
easier to clean and let the boat go faster.)

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://SportToday.org/
Our BVI FAQs (290+ pics) http://SportToday.org/

 
 
 

To bond or not to bond... that is the question

Post by MMC » Tue, 03 Dec 2002 02:36:21

I just tossed the engine scoop strainer over the side. This thing was
restrictive at sailboat speed with a couple coat of barrier coat and a
couple coats of bottom paint AND an oyster living inside (almost same
diameter as inside of strainer)!


Quote:



> >>>OK. Doing a peel job now, all thru-hulls out. Once they're back in, I'm
> >>>installing 7 bronze Groco strainers over mushroom thru-hulls. The
> >>>thru-hulls are all bonded. I am wondering if I should bond the
strainers
> >>>as well, by putting a long machine***through the hull and attaching
> >>>them to the bonding system, or just use short screws to affix them to
> >>>the hull. They wouldn't touch the mushroom thru-hulls. My guess is that
> >>>they wouldn't suffer much if I didn't bond them, but asking for
> >>>opinions/suggestions. Using silicon bronze screws to attach them to the
> >>>hull.

> >>7 Grocos! That sounds like overkill -- most only put them on the fresh
> >>water cooling, saving  money by using cheap filters for the inlets that
> >>don't get that sort of volume flow -- or do you have 7 cooling circuits?

> >>If the filters are above the standing waterline (as they should be),
> >>there's no need to bond. If below, it's a personal decision. Even the
> >>AYBC is split between bonding or isolating through hulls. In many cases,
> >>bonding makes it possible to lose them through electrolysis or lightning
> >>strike; leaving them isolated submits them to only normal corrosion


> >  These are all strainers below the waterline outside the hull. They
cover
> >mushroom thru-hulls that are bonded, but won't touch them. Two head
> >intakes, one A/C, one SW washdown pump, ME, genset, reefer. They are
> >different types, based on flow rates. All bronze, will be affixed to a
> >fiberglass hull with bronze screws.

> Oops! I forgot Grocco had something other than the basket strainers.

> If they don't touch any other metal, I'd probably leave them unbonded.
> If they DO touch dissimilar metal, it'll probably be the through hull,
> so will have the same bonding.

> The only exception I could think of would be where through-bolts/screws
> stand in bilge water with a bilge pump or switch that could short and
> "electrify" the water. Probably would consider screws that don't go
> through, but are between standing bilge water and "outside" as needing
> bonding. Who knows what currents the screws could conduct in that case.
> I wouldn't be worried about the strainers as much as the screws. If the
> strainer falls off, the boat won't sink. If a***disintegrates,
> that's a possible hole through the hull.

> (Personally, I like flush through hulls with inside strainers. They're
> easier to clean and let the boat go faster.)

> --
> Jere Lull
> Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
> Xan's Pages: http://SportToday.org/
> Our BVI FAQs (290+ pics) http://SportToday.org/