[bolger] Re: WDJ supplemental ballast

Gregg Carlson wisely wrote (now there's a plug...):
BO>If you insist, reading Gougeon Brothers: "There are problems with with
BO>developing good bonds, and preparation is necessary...adhesive bonding of
BO>metal is a relatively new and complex field..."

Now might also be a good time for people to head for their local library
to reference the Gougeon Brothers re hardware bonding and sinking
rot-proof bolts into plywood!

Tim & Flying Tadpole
Bill - All very interesting- What do you think your total trailering weight
comes up to? What do you pull her with and how has that worked out? And one
more tangential question - what does your maximum total sail area add up to
and have you ever had that much sail up? Steve
Steve,
    Bolger's early conceptual drawings of the WDJ showed water ballast of 1500 lbs.. and no batteries. The final plans had shorter ballast tanks of 1200 lbs. capacity and two 8-D batteries which weigh 320 lbs.. total. So far Sapphire has only one small battery which weighs about 35 lbs.. I keep overlooking this difference and perhaps Bolger was unaware when he wrote that her ability to carry sail was less than anticipated.
    So, all the more reason I should continue with my internal lead ballast. Someday, a future owner might want a gyroscopically stabilized satellite antenna and color TV. In which case the lead could be removed and the 8-Ds added.
    In making your ballast comparisons between MJ and WDJ consider also the relative displacements. MJ is 2700 lbs.. and WDJ is 4900 lbs.. It is interesting that a mere 2 feet of length and 1 foot of beam can almost double the displacement.
Bill Jochems
From: "Donald Hodges" <dhodges@...>
To: <bolger@egroups.com>
Sent: Wednesday, March 29, 2000 9:37 PM
Subject: [bolger] Re: WDJ supplemental ballast


> This proves that old adage: "Most of the the things we fear most in life
> never really happen..." Or the other one: "Never overlook the
"do-nothing"
> alternative..."

If you are building a boat from scratch that needs a lot of ballast steel
at $0.25 cents a pound is pretty cheap. A 3/8 in steel bottom would
be a practical alternative.

The engineering of a steel bottom to plywood sides would be a little
different but it should be possible.

Now if I can only find some 1/2 inch copper a the scrap yard.....

Gordon W5RED

G. C. Cougergcouger@...Stillwater, OK
www.couger.com/gcouger
"You miss 100 percent of the shots you never take." - Wayne Gretzky
This proves that old adage: "Most of the the things we fear most in life
never really happen..." Or the other one: "Never overlook the "do-nothing"
alternative..."

Sure glad I don't have to debate our host and Tim any more on this one. My
parting shot: I have my own copy of Gougeon and I still would not use bolts
to attach a flat plate to a flat boat with 2 1/2 inches of deadwood.

Don Hodges, who attached a 16-foot-long marine plywood bottom to Sweet
Caroline today using two quarts
of thickened epoxy (hope I got that out of my system), then went sailing the
12-foot skiff

From: William D> Jochems <wjochems@...>
To: <bolger@egroups.com>
Sent: Wednesday, March 29, 2000 10:23 AM
Subject: [bolger] Re: WDJ supplemental ballast


> But then Ed Haile asked how the steel outside was going to be an
> improvement over the lead inside. Now that I think about it, little or
> nothing would be accomplished.
The current method used by steelboat builders is to sandblast the steel with
sharp abrasive and then emeadiatly
apply the epoxy befor rust can form from the moisture in the air. The Navy
does this and most of the worlds shipbuilders too. Have you ever noticed
that steel ships are not as rusty nowadays as when we were young? (I'm 50)
Hope this helps
Steve Yahn


At 07:13 PM 03/28/2000 -0600, you wrote:
>Epoxy on flat steel? Well...not me...a little oil or mill scale and you
>could leave it all behind.
>
>If you insist, reading Gougeon Brothers: "There are problems with with
>developing good bonds, and preparation is necessary...adhesive bonding of
>metal is a relatively new and complex field..." 1. Clean with solvent to
>remove all grease, wiping several times. 2. Sand surface with 60 grit. 3.
>Thin coat. 4. Sand again while resin is wet to avoid all corrosion. 5.
>Assemble.
>
>Gregg Carlson
>
>
>
>At 06:55 PM 3/28/2000 -0600, you wrote:
>> Epoxy. epoxy, epoxy! I would take the curve off the boat rather than
>>the plans (rip a 3x7 doorskin in half longwise and plot the curve on it),
>>and then, assuming it fits, put a 2-inch stainless or galvanized
>> All this assumes he boat is upright! Don Hodges
>>dhodges@...
>>http://www.ecoastlife.com
>>Your Cyber-Vacation - Loafing on the Emerald Coast
>>Small Boats, Building, Fishing, Paddling, Rowing, Sailing -----
>>Original Message ----- From: > Jochems To: Bolger Sent:
>>Tuesday, March 28, 2000 12:08 PM Subject: [bolger] WDJ supplemental
>>ballast
>> Dear Bolgeristas, &F. (This will replace my present lead ballast
>>supplement which is inside the hull.) Would the attachment be
>>easier if the plate were cut in thirds (each piece being 3'4''
>>long)? The bottom is two layers of half inch plywood and below
>>the bottom is a 2 foot wide shoe comprised of two layers of three
>>quarter inch plywood. The steel goes on the bottom of the shoe; so above
>>the steel will be 2 and 1/2 inches of plywood. I know that the
>>most secure fasteners would be through bolts; but then I would have bolt
>>heads on the cabin floor and nuts on the bottom of the steel plate which
>>I might not be able to fully inset. Also, I would have holes all the way
>>through the bottom of the boat. How about screws, up through
>>the plate, into the plywood? What size screws, how long and on what
>>spacing? How can I best discourage rot around the screws? I solicit
>>your comments. Bill Jochems
>> eGroups.com Home:http://www.egroups.com/group/bolger
>>www.egroups.com - Simplifying group communications
>>
>>
>> eGroups.com Home:http://www.egroups.com/group/bolger
>> www.egroups.com - Simplifying group communications
>>
>
>
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Good point - that piece of wood is about 6 times stiffer. But, steel is 4
or 5 times stronger, and much, much more patient than that wood and its
screws......boing!!

Anyway, the inquirer has already retreated!

Gregg Carlson

>I did a quick calculation. If the wood is 2.5" and the steel is 0.5",
>then you'd have to be using light balsa (around 5 or 6 lbs/ft3) before
>the wood was more flexible than the steel. Stiffness goes with the cube
>of the thickness, all else being equal and my brain still functional
>(always a question), as well as with the material properties. I did a
>lot of measurements on balsa for my model airplanes. (that's for a
>sheet. stiffness of a round pole is proportional to 4th power of the
>diameter because you are changing the "width" as well)
ghc <ghart-@...> wrote:
original article:http://www.egroups.com/group/bolger/?start=4021
>snip
> But, you're right, it would be a little easier to make small
adjustments
> this way, but I think the wood is going to be the one adjusting.

I did a quick calculation. If the wood is 2.5" and the steel is 0.5",
then you'd have to be using light balsa (around 5 or 6 lbs/ft3) before
the wood was more flexible than the steel. Stiffness goes with the cube
of the thickness, all else being equal and my brain still functional
(always a question), as well as with the material properties. I did a
lot of measurements on balsa for my model airplanes. (that's for a
sheet. stiffness of a round pole is proportional to 4th power of the
diameter because you are changing the "width" as well)
Bill -
Ballasting discussions are near and dear to me!:-)

So you are currently carrying 1570 lbs of ballast (the original 1200 water
ballast and 370 lead you added) The total recommended ballast of the schooner
is now 1200 lbs water and 408 in the form of a steel plate attached to the
bottom - And the goal behind the metal plate was to increase the ballast
by another 38lbs and perhaps lower it. Sounds like a lot of work and expense
to gain 38 more pounds of ballast - which may or may not actually be lower! I
think I'd just reef sooner!

Sounds like an easy choice to me. I always wonder about the toxicity of lead
inside - maybe you want to attach the lead which is inside and glass it over?


As I am sure you can imagine I'm working the comparisions in my head - wdj -
25.6 feet long, 7 feet wide - unimaginable amount of sail area - 1600 lbs of
ballast - Martha Jane - 23.6 feet long - 6 feet wide - 245 sq. feet of sail -
my current 800 lbs of ballast - Steve
The reference is "The Gougeon Brothers on Boat Construction" ISBN
0-87812-166-8. They describe bedding fasteners in a cylinder of epoxy
(where the teeth grip the epoxy and the epoxy grips the wood).

GHC

At 08:50 PM 3/29/2000 -93000, you wrote:
>Gregg Carlson wisely wrote (now there's a plug...):
>BO>If you insist, reading Gougeon Brothers: "There are problems with with
>BO>developing good bonds, and preparation is necessary...adhesive bonding of
>BO>metal is a relatively new and complex field..."
>
>Now might also be a good time for people to head for their local library
>to reference the Gougeon Brothers re hardware bonding and sinking
>rot-proof bolts into plywood!
>
>Tim & Flying Tadpole
Wouldn't the inside of the bottom look like the outside? If so, the cg
would be 2-1/2" lower, plus you'll never have to worry about a grounding.
Maybe a better idea if employed from the beginning.

Gregg Carlson


At 09:23 AM 3/29/2000 -0700, you wrote:
> But then Ed Haile asked how the steel outside was going to be an
>improvement over the lead inside. Now that I think about it, little or
>nothing would be accomplished. I have 370 lbs.. of lead in 1/8" sheets
>spread over about 4 square feet in the lowest part of the hull. The lead
>cannot shift and is covered with Rubbermaid shower mats. The steel plate
>would have been 10' long and curved to the rocker so the center of gravity
>would not have been lower.
But you still have to roll them... The Micro would have a rocker of about
10" over 10 feet (maybe the WDJ is similar), and it would still take 350
pounds on each end of each of your 8" plates to make this bend. As soon as
your mother-in-law climbs down, it'll try to straighten with a similar
force. (Be sure to nail the bottom pretty good into the sides ;-)

But, you're right, it would be a little easier to make small adjustments
this way, but I think the wood is going to be the one adjusting. If you
put this plate on without bending, the bottom is going to look like a saddle.

Gregg Carlson


At 07:13 PM 3/28/2000 -0600, you wrote:
> If I was going to cut it up to make it easier to handle I would cut it
>into three 8 inch wide pieces. You won't need to get the rocker very close
>because the steel will bend enought to fit a good deal of miss match. If
>you epoxy it on you will have one hell for stout bottom. I pity the poor
>container you run over, if you hit is square on. A steel bottomed sharpy
>would be an interesting boat. W5RED G. C. Couger
Bolgeristas,
Thank you for your ideas. I had not thought of cutting the plate
lengthwise to facilitate adjusting the curve or bonding the plate to the
bottom. And I had overlooked the obvious idea of measuring the rocker on the
boat as built, rather than going by the plan.
But then Ed Haile asked how the steel outside was going to be an
improvement over the lead inside. Now that I think about it, little or
nothing would be accomplished. I have 370 lbs.. of lead in 1/8" sheets
spread over about 4 square feet in the lowest part of the hull. The lead
cannot shift and is covered with Rubbermaid shower mats. The steel plate
would have been 10' long and curved to the rocker so the center of gravity
would not have been lower.
Ed also said "Part of being a low tension rig is yielding. The question
is how quickly she rights once you let go." This leads into Steve's question
concerning specifications and asking why the change now.
Sapphire is the prototype WDJ with a birdwatcher style sharpie hull,
schooner rig and 1200 lbs. of water ballast. The boat seemed overly tender
to me and PCB&F agreed, writing "The boat's power to carry sail, though
adequate, was less than we expected." The plans were modified to provide for
shorter masts, hollow gaffs and booms or the addition of some fixed ballast.
I made all these changes and now the boat is exactly where I want her on the
tenderness scale. She may be stiffer than some sharpie fans would prefer.
In wind up to about 12 mph I must sit my 100 kilos on the lee side to get
her sufficiently heeled.
Incidentally, through my inadvertence, Sapphire was knockdown tested
before any of the changes. She bounced back reassuringly, as if she had
compressed a big spring.
Bill Jochems
From:Hwal@...<Hwal@...>
To:bolger@egroups.com<bolger@egroups.com>
Date: Tuesday, March 28, 2000 4:40 PM
Subject: [bolger] Re: WDJ supplemental ballast


>In a message dated 3/28/2000 1:43:48 PM Eastern Standard Time,
>ghartc@...writes:
>
><< Dear Bolgeristas, I am planning to add a 1/2 inch steel plate 24''
> wide by 10' long to the bottom of my WDJ. This will supplement the water
> ballast by 408 lbs.. and has been suggested by PCB&F. (This will replace
my
> present lead ballast supplement which is inside the hull.) >>
>
>Hi Bill - Very interesting. Can you tell us what the original plans called
>for and why the change at this time? What amount of internal lead ballast
>were you carrying? As you probably know - I have supplemented my ballast by
>300 lbs of internal lead and was real pleased with the feel of the boat in
>heavy winds two weeks ago.
>Steve ( Landroval)
>
>------------------------------------------------------------------------
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I think you can get the same results with phosporic acid (Os -Pho or
similar) on steel, but you are right, it must be clean, whether it's epoxy
or 5200 - I just don't think bolts are necessary for a plate. At 400 lb and
2880 square inches, it only needs 0.15 psi average to hold it. The drive
screws would probably hold it alone, but I would sleep soundly with either
epoxy or 5200. (I'm in epoxy mode with my own project this week!<g>)

A lot of metal aircraft parts are bonded these days, and it's surprising how
clean a piece can be after just a strong alkaline wash, similar to
dishwasher detergent.

Now, a 4-10,000 pound lead keel 4 to 6 feet deep and subject to grounding is
another matter...

Don Hodges
dhodges@...
http://www.ecoastlife.com
Your Cyber-Vacation - Loafing on the Emerald Coast
Small Boats, Building, Fishing, Paddling, Rowing, Sailing
----- Original Message -----
From: GHC <ghartc@...>
To: <bolger@egroups.com>
Sent: Tuesday, March 28, 2000 7:13 PM
Subject: [bolger] Re: WDJ supplemental ballast


> Epoxy on flat steel? Well...not me...a little oil or mill scale and you
> could leave it all behind.
>
> If you insist, reading Gougeon Brothers: "There are problems with with
> developing good bonds, and preparation is necessary...adhesive bonding of
> metal is a relatively new and complex field..." 1. Clean with solvent to
> remove all grease, wiping several times. 2. Sand surface with 60 grit. 3.
> Thin coat. 4. Sand again while resin is wet to avoid all corrosion. 5.
> Assemble.
>
> Gregg Carlson
>
>
>
> At 06:55 PM 3/28/2000 -0600, you wrote:
> > Epoxy. epoxy, epoxy! I would take the curve off the boat rather
than
> >the plans (rip a 3x7 doorskin in half longwise and plot the curve on it),
> >and then, assuming it fits, put a 2-inch stainless or galvanized
> > All this assumes he boat is upright! Don Hodges
> >dhodges@...
> >http://www.ecoastlife.com
> >Your Cyber-Vacation - Loafing on the Emerald Coast
> >Small Boats, Building, Fishing, Paddling, Rowing, Sailing -----
> >Original Message ----- From: > Jochems To: Bolger Sent:
> >Tuesday, March 28, 2000 12:08 PM Subject: [bolger] WDJ supplemental
> >ballast
> > Dear Bolgeristas, &F. (This will replace my present lead ballast
> >supplement which is inside the hull.) Would the attachment be
> >easier if the plate were cut in thirds (each piece being 3'4''
> >long)? The bottom is two layers of half inch plywood and below
> >the bottom is a 2 foot wide shoe comprised of two layers of three
> >quarter inch plywood. The steel goes on the bottom of the shoe; so
above
> >the steel will be 2 and 1/2 inches of plywood. I know that the
> >most secure fasteners would be through bolts; but then I would have bolt
> >heads on the cabin floor and nuts on the bottom of the steel plate
which
> >I might not be able to fully inset. Also, I would have holes all the
way
> >through the bottom of the boat. How about screws, up through
> >the plate, into the plywood? What size screws, how long and on what
> >spacing? How can I best discourage rot around the screws? I solicit
> >your comments. Bill Jochems
> > eGroups.com Home:http://www.egroups.com/group/bolger
> >www.egroups.com - Simplifying group communications
> >
> >
> > eGroups.com Home:http://www.egroups.com/group/bolger
> > www.egroups.com - Simplifying group communications
> >
>
>
> ------------------------------------------------------------------------
> DON'T HATE YOUR RATE!
> Get a NextCard Visa, in 30 seconds! Get rates as low as
> 0.0% Intro or 9.9% Fixed APR and no hidden fees.
> Apply NOW!
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>
> -- Easily schedule meetings and events using the group calendar!
> --http://www.egroups.com/cal?listname=bolger&m=1
>
>
>
Epoxy on flat steel? Well...not me...a little oil or mill scale and you
could leave it all behind.

If you insist, reading Gougeon Brothers: "There are problems with with
developing good bonds, and preparation is necessary...adhesive bonding of
metal is a relatively new and complex field..." 1. Clean with solvent to
remove all grease, wiping several times. 2. Sand surface with 60 grit. 3.
Thin coat. 4. Sand again while resin is wet to avoid all corrosion. 5.
Assemble.

Gregg Carlson



At 06:55 PM 3/28/2000 -0600, you wrote:
> Epoxy. epoxy, epoxy! I would take the curve off the boat rather than
>the plans (rip a 3x7 doorskin in half longwise and plot the curve on it),
>and then, assuming it fits, put a 2-inch stainless or galvanized
> All this assumes he boat is upright! Don Hodges
>dhodges@...
>http://www.ecoastlife.com
>Your Cyber-Vacation - Loafing on the Emerald Coast
>Small Boats, Building, Fishing, Paddling, Rowing, Sailing -----
>Original Message ----- From: > Jochems To: Bolger Sent:
>Tuesday, March 28, 2000 12:08 PM Subject: [bolger] WDJ supplemental
>ballast
> Dear Bolgeristas, &F. (This will replace my present lead ballast
>supplement which is inside the hull.) Would the attachment be
>easier if the plate were cut in thirds (each piece being 3'4''
>long)? The bottom is two layers of half inch plywood and below
>the bottom is a 2 foot wide shoe comprised of two layers of three
>quarter inch plywood. The steel goes on the bottom of the shoe; so above
>the steel will be 2 and 1/2 inches of plywood. I know that the
>most secure fasteners would be through bolts; but then I would have bolt
>heads on the cabin floor and nuts on the bottom of the steel plate which
>I might not be able to fully inset. Also, I would have holes all the way
>through the bottom of the boat. How about screws, up through
>the plate, into the plywood? What size screws, how long and on what
>spacing? How can I best discourage rot around the screws? I solicit
>your comments. Bill Jochems
> eGroups.com Home:http://www.egroups.com/group/bolger
>www.egroups.com - Simplifying group communications
>
>
> eGroups.com Home:http://www.egroups.com/group/bolger
> www.egroups.com - Simplifying group communications
>
If I was going to cut it up to make it easier to handle I would cut it
into three 8 inch wide pieces. You won't need to get the rocker very
close because the steel will bend enought to fit a good deal of miss
match.
 
If you epoxy it on you will have one hell for stout bottom. I pity the poor
container you run over, if you hit is square on.
 
A steel bottomed sharpy would be an interesting boat.
 
Gordon    W5RED
 
G. C. Cougergcouger@...  Stillwater, OK
www.couger.com/gcouger
"You miss 100 percent of the shots you never take."   - Wayne Gretzky
 

 
----- Original Message -----
Sent:Tuesday, March 28, 2000 6:55 PM
Subject:[bolger] Re: WDJ supplemental ballast

Epoxy. epoxy, epoxy!
 
I would take the curve off the boat rather than the plans (rip a 3x7 doorskin in half longwise and plot the curve on it), and then, assuming it fits, put a 2-inch stainless or galvanized
drive screw every 12 inches, placed 1 inch inside the edges (have the metal worker drill and countersink these holes).  The screws are just to clamp the piece to the  bottom until the epoxy sets.  Mix up batches of epoxy totalling a quart of liquid ( a quart all at once might "go off" and set up prematurely).  Thicken with talc or your choice of structural thickeners to peanut butter viscosity.  Jack the piece (or pieces) into place, butter the whole faying surface of the steel with epoxy, jack some more to get in range  of the screws, and run the screws in to clamp.  Dip the screws in epoxy resin to seal the hole, cover the screwheads with thickened epoxy... oh, and sand to bare wood for the faying surface on the boat.   All this assumes he boat is upright!
 
Don Hodges
dhodges@...
http://www.ecoastlife.com
Your Cyber-Vacation - Loafing on the Emerald Coast
Small Boats, Building, Fishing, Paddling, Rowing, Sailing
----- Original Message -----
Sent:Tuesday, March 28, 2000 12:08 PM
Subject:[bolger] WDJ supplemental ballast

Dear Bolgeristas,
    I am planning to add a 1/2 inch steel plate 24'' wide by 10' long to the bottom of my WDJ. This will supplement the water ballast by 408 lbs.. and has been suggested by PCB&F. (This will replace my present lead ballast supplement which is inside the hull.)
    A local metal worker says he can bend the plate to the same curve as the rocker shown on the Bolger plans. But what if my boat's rocker does not exactly match the plans?  Would the attachment be easier if the plate were cut in thirds
(each piece being 3'4'' long)?
    Also, I haven't decided how best to fasten these plates to the bottom.  The bottom is two layers of half inch plywood and below the bottom is a 2 foot wide shoe comprised of two layers of three quarter inch plywood. The steel goes on the bottom of the shoe; so above the steel will be 2 and 1/2 inches of plywood.
    I know that the most secure fasteners would be through bolts; but then I would have bolt heads on the cabin floor and nuts on the bottom of the steel plate which I might not be able to fully inset. Also, I would have holes all the way through the bottom of the boat.
    How about screws, up through the plate, into the plywood? What size screws, how long and on what spacing? How can I best discourage rot around the screws?
    I solicit your comments.
Bill Jochems
   
   
eGroups.com Home:http://www.egroups.com/group/bolger
www.egroups.com- Simplifying group communications
eGroups.com Home:http://www.egroups.com/group/bolger
www.egroups.com- Simplifying group communications
Epoxy. epoxy, epoxy!
 
I would take the curve off the boat rather than the plans (rip a 3x7 doorskin in half longwise and plot the curve on it), and then, assuming it fits, put a 2-inch stainless or galvanized
drive screw every 12 inches, placed 1 inch inside the edges (have the metal worker drill and countersink these holes).  The screws are just to clamp the piece to the  bottom until the epoxy sets.  Mix up batches of epoxy totalling a quart of liquid ( a quart all at once might "go off" and set up prematurely).  Thicken with talc or your choice of structural thickeners to peanut butter viscosity.  Jack the piece (or pieces) into place, butter the whole faying surface of the steel with epoxy, jack some more to get in range  of the screws, and run the screws in to clamp.  Dip the screws in epoxy resin to seal the hole, cover the screwheads with thickened epoxy... oh, and sand to bare wood for the faying surface on the boat.   All this assumes he boat is upright!
 
Don Hodges
dhodges@...
http://www.ecoastlife.com
Your Cyber-Vacation - Loafing on the Emerald Coast
Small Boats, Building, Fishing, Paddling, Rowing, Sailing
----- Original Message -----
Sent:Tuesday, March 28, 2000 12:08 PM
Subject:[bolger] WDJ supplemental ballast

Dear Bolgeristas,
    I am planning to add a 1/2 inch steel plate 24'' wide by 10' long to the bottom of my WDJ. This will supplement the water ballast by 408 lbs.. and has been suggested by PCB&F. (This will replace my present lead ballast supplement which is inside the hull.)
    A local metal worker says he can bend the plate to the same curve as the rocker shown on the Bolger plans. But what if my boat's rocker does not exactly match the plans?  Would the attachment be easier if the plate were cut in thirds
(each piece being 3'4'' long)?
    Also, I haven't decided how best to fasten these plates to the bottom.  The bottom is two layers of half inch plywood and below the bottom is a 2 foot wide shoe comprised of two layers of three quarter inch plywood. The steel goes on the bottom of the shoe; so above the steel will be 2 and 1/2 inches of plywood.
    I know that the most secure fasteners would be through bolts; but then I would have bolt heads on the cabin floor and nuts on the bottom of the steel plate which I might not be able to fully inset. Also, I would have holes all the way through the bottom of the boat.
    How about screws, up through the plate, into the plywood? What size screws, how long and on what spacing? How can I best discourage rot around the screws?
    I solicit your comments.
Bill Jochems
   
   
eGroups.com Home:http://www.egroups.com/group/bolger
www.egroups.com- Simplifying group communications
In a message dated 3/28/2000 1:43:48 PM Eastern Standard Time,
ghartc@...writes:

<< Dear Bolgeristas, I am planning to add a 1/2 inch steel plate 24''
wide by 10' long to the bottom of my WDJ. This will supplement the water
ballast by 408 lbs.. and has been suggested by PCB&F. (This will replace my
present lead ballast supplement which is inside the hull.) >>

Hi Bill - Very interesting. Can you tell us what the original plans called
for and why the change at this time? What amount of internal lead ballast
were you carrying? As you probably know - I have supplemented my ballast by
300 lbs of internal lead and was real pleased with the feel of the boat in
heavy winds two weeks ago.
Steve ( Landroval)
Hello Guys
 
If using bolts the golden rule IMO is to ensure that they don't have thread all the way down/up to the head (as in most machine screws with countersunk heads), or that the thread isn't greater in diameter than the shank (as with most galvanized rolled thread bolts)
 
Given the thickness of the bottom (2 1/2" by my reckoning) I'd use 2 1/2" galvanized lags ( some call these coach scews) fastened up through the steel into the plywood.  I'd use about 3/8" diameter lags at about 1 foot centers i.e. in 3 rows of 11 lags .   The heads of the lags will stick out a bit and over time may get rounded off from any contacts the boat may make with the ground/trailer/etc. but it won't matter.
 
Some would say that you shouldn't use lags to attach ballast but in this case there are no (well negible anyway) twisting/wracking forces on the fastenings so more sophisticated engineering isn't required.
 
I very much doubt that it is necessary to worry about rot under the steel plate/around the scews.
 
Smaller pieces of plate will be easier to handle but less easily adjusted in terms of rocker.  I'd be inclined to spile off a pattern of the rocker for the plate bender to work to, then commence fastening in the middle, working to the ends.
 
Just my thoughts,  as with all advice that one obtains from internet sources, weigh it against your own and others opinions.
 
Regards - Foster Price
-----Original Message-----
From:William D> Jochems [mailto:wjochems@...]
Sent:Wednesday, 29 March 2000 06:08
To:Bolger
Subject:[bolger] WDJ supplemental ballast

Dear Bolgeristas,
    I am planning to add a 1/2 inch steel plate 24'' wide by 10' long to the bottom of my WDJ. This will supplement the water ballast by 408 lbs.. and has been suggested by PCB&F. (This will replace my present lead ballast supplement which is inside the hull.)
    A local metal worker says he can bend the plate to the same curve as the rocker shown on the Bolger plans. But what if my boat's rocker does not exactly match the plans?  Would the attachment be easier if the plate were cut in thirds
(each piece being 3'4'' long)?
    Also, I haven't decided how best to fasten these plates to the bottom.  The bottom is two layers of half inch plywood and below the bottom is a 2 foot wide shoe comprised of two layers of three quarter inch plywood. The steel goes on the bottom of the shoe; so above the steel will be 2 and 1/2 inches of plywood.
    I know that the most secure fasteners would be through bolts; but then I would have bolt heads on the cabin floor and nuts on the bottom of the steel plate which I might not be able to fully inset. Also, I would have holes all the way through the bottom of the boat.
    How about screws, up through the plate, into the plywood? What size screws, how long and on what spacing? How can I best discourage rot around the screws?
    I solicit your comments.
Bill Jochems
   
   
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Bill,

I did a similar thing to my Micro, adding a 25 lb. steel strap to the bottom.

Don't cut it - or it will never be fair! To give you an idea, if you pick
it up in the middle, the ends will sag .75 inch. Then, if you and a friend
sit on both ends (e.g. 175 lbs), the ends will droop another 1.7 inches.
So, you will have to have it rolled on some radius. I would measure your
boat and approximate it, using it as a structural member.

I would bed it in 5200 and bolt it, although I'm sure pairs of screws
bedded in epoxy every 12 or 18 inches or so would be fine. It's not that
heavy. It you were worried about it, you could add 2 or 3 bolts, even
tapped into a internal plate(s).

Gregg Carlson

At 11:08 AM 3/28/2000 -0700, you wrote:
> Dear Bolgeristas, I am planning to add a 1/2 inch steel plate 24''
wide by 10' long to the bottom of my WDJ. This will supplement the water
ballast by 408 lbs.. and has been suggested by PCB&F. (This will replace my
present lead ballast supplement which is inside the hull.)
A local metal worker says he can bend the plate to the same curve as
the rocker shown on the Bolger plans. But what if my boat's rocker does not
exactly match the plans? Would the attachment be easier if the plate were
cut in thirds
(each piece being 3'4'' long)?
Also, I haven't decided how best to fasten these plates to the bottom.
The bottom is two layers of half inch plywood and below the bottom is a 2
foot wide shoe comprised of two layers of three quarter inch plywood. The
steel goes on the bottom of the shoe; so above the steel will be 2 and 1/2
inches of plywood.
I know that the most secure fasteners would be through bolts; but then
I would have bolt heads on the cabin floor and nuts on the bottom of the
steel plate which I might not be able to fully inset. Also, I would have
holes all the way through the bottom of the boat.
How about screws, up through the plate, into the plywood? What size
screws, how long and on what spacing? How can I best discourage rot around
the screws?
I solicit your comments.
Bill Jochems
Dear Bolgeristas,
    I am planning to add a 1/2 inch steel plate 24'' wide by 10' long to the bottom of my WDJ. This will supplement the water ballast by 408 lbs.. and has been suggested by PCB&F. (This will replace my present lead ballast supplement which is inside the hull.)
    A local metal worker says he can bend the plate to the same curve as the rocker shown on the Bolger plans. But what if my boat's rocker does not exactly match the plans?  Would the attachment be easier if the plate were cut in thirds
(each piece being 3'4'' long)?
    Also, I haven't decided how best to fasten these plates to the bottom.  The bottom is two layers of half inch plywood and below the bottom is a 2 foot wide shoe comprised of two layers of three quarter inch plywood. The steel goes on the bottom of the shoe; so above the steel will be 2 and 1/2 inches of plywood.
    I know that the most secure fasteners would be through bolts; but then I would have bolt heads on the cabin floor and nuts on the bottom of the steel plate which I might not be able to fully inset. Also, I would have holes all the way through the bottom of the boat.
    How about screws, up through the plate, into the plywood? What size screws, how long and on what spacing? How can I best discourage rot around the screws?
    I solicit your comments.
Bill Jochems