RE: [bolger] Copper powder/epoxy bottom treatment?

This sounds like a product called CopperBot. They claim that it is effective
for 10 years. I have heard several good reports of it. It does not replace
epoxy coating for osmosis etc but goes over it. I have seen one boat where
it was spread too cold. The hull was covered in smears and runs where they
had been unable to brush it out enough.
I understand that there are no electrolysis problems but I am not sure of
that.
It works partly by constantly corroding so I am sure your drive would go a
tasteful shade of green.


-----Original Message-----
From: Paul A. Lefebvre, Jr. [mailto:paul@...]
Sent: 29 August 2000 17:37
To:bolger@egroups.com
Subject: [bolger] Copper powder/epoxy bottom treatment?


Greetings, Bolgeristas! (just saw that somewhere in one of the recent
postings, and loved it!)

I've heard of some copper powder
you can mix with epoxy and apply as a more lasting bottom treatment - has
anyone had any experience with this? Does it work at impeding marine growth?
And for the short term, if it's on a trailered boat, does it leach off in
the rain and turn your trailer, driveway, bottom of your boat, etc. green?
And what about electrolysis issues with rudder fittings, lead keel, or an
outboard you forgot to tip up while at mooring? Any info would be
appreciated....

thanks,

Paul



Paul Lefebvre
paul@...



Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.
>
> I think something about 35-40 feet, of shallow to moderate draft,
offshore
> capable, and of simple traditional round bilge construction will
fill the
> bill.

I nominate "Forest Belle." I think the design appeared in an article
in WoodenBoat about how a wood design could compete with a FG one.
Its a very traditional yawl with a big main. The boat is fairly
narrow and deep, as I recall. The idea was to make a boat that was
very easy to build and to sail, with the downside that it is a little
big (long) for its accomdations by current standards.

And beautiful.

Peter
A couple of years ago I asked the people at WEST in Germany about their
copper powder. They recommended Awlstar antifouling instead.

>I remember a boatbuilding site where it was applied during
>constructions.

Mark and I choose Copperpoxy:
http://www.alaska.net/~mzeiger/MJbottom.html
http://www.leow.de/tips/tips.html

Tim Fatchen has in water experience with an Australian brand.
There is Copperbot (UK manufactured) that one can apply by spray gun.

Leo
Foster,

I live close to the native stands of "Cupressus macrocarpa" (Monterey
Cypress), here it's considered such a poor wood that you can't even
give the stuff away for firewood, and I can't begin to tell you how
many I've cut down due to coryneum canker.
There is one growing on a rock in the ocean, near the Pebble Beach
Golf Course, called the "Lone Cypress" that they claim is the most
photographed tree in the world. You made my day telling me that this
species can grow into such a great boat building timber.

Good luck in your search for a design.

Rick


> here in New Zealand call "Marcacarpa" (Yanks will know it as
"Monterey
> Cypress", although trees grown here produce a slightly different
timber that
> is reckoned to be superior to the original). Now this is about as
fine a
> boatbuilding timber that one can get anywhere, we've used it for
structure,
> planking, and fitting out in other boats. There's enough for a
small ship.
Hello Guys

I'm wrestling with a difficult work problem here so how about a bit of
diversionary procrastination on boats ??

Recently I did a deal which has secured me a very large quantity of what we
here in New Zealand call "Marcacarpa" (Yanks will know it as "Monterey
Cypress", although trees grown here produce a slightly different timber that
is reckoned to be superior to the original). Now this is about as fine a
boatbuilding timber that one can get anywhere, we've used it for structure,
planking, and fitting out in other boats. There's enough for a small ship.

If I don't come up with a project for this timber, my wife (bless her)
thinks she'll collar it for new kitchen joinery.

I have all Bolgers books and some designs from these do appeal including
"Sweet Chariot", "Shearwater" and "Antaxia". None of them are "the" boat
however.

I think something about 35-40 feet, of shallow to moderate draft, offshore
capable, and of simple traditional round bilge construction will fill the
bill.

Now I know PCB has done many designs apart from those he's published in
books so I'd love too get some ideas please.

Regards

Foster Price
Southland, New Zealand
> In the final 2 coats I added WEST
> copper
> powder. (I'm using Raka epoxy). WEST claims that their copper
powder
> makes a harder, more waterproof surface with backup antifouling
> properties.


Vince,

I can see where that copper/epoxy mix would make a harder bottom, but
I'm still not convinced you'll get much (if any) anti-foul protection.

Could I convince you to make up three small plywood squares, coat one
with straight epoxy, one with your copper/epoxy, and one with your
copper/epoxy plus antifoul paint? Then hang them in the water and by
the time you are near launch date you'll know what to do!

Anyway, I think Dakota is a great design.

Rick
Rick (et al),

I prefinished the bottom layers of my DAKOTA project with 3 coats of
epoxy over 6 oz. glass cloth. In the final 2 coats I added WEST
copper
powder. (I'm using Raka epoxy). WEST claims that their copper powder
makes a harder, more waterproof surface with backup antifouling
properties. I won't know about their claims until I finish and launch
the boat (hopefully summer 2001), but I do know that the surface is
very glossy and smooth, seems quite hard, and is almost too pretty a
burgundy to paint over.

Vince Chew


--- Inbolger@egroups.com, "Peter Vanderwaart" <pvanderw@o...> wrote:
> --- Inbolger@egroups.com, "Rick " <sctree@d...> wrote:
> > > I've heard of some copper powder
> > > you can mix with epoxy and apply as a more lasting bottom
> treatment
>
> See
>
>http://www.copperpoxy.com/index.html
>
> I remember a boatbuilding site where it was applied during
> constructions. You might try a Yahoo or Google search. I think it
was
> a Michulak boat.
>
> PHV
--- Inbolger@egroups.com, "Rick " <sctree@d...> wrote:
> > I've heard of some copper powder
> > you can mix with epoxy and apply as a more lasting bottom
treatment

See

http://www.copperpoxy.com/index.html

I remember a boatbuilding site where it was applied during
constructions. You might try a Yahoo or Google search. I think it was
a Michulak boat.

PHV
> I've heard of some copper powder
> you can mix with epoxy and apply as a more lasting bottom treatment
- has
> anyone had any experience with this? Does it work at impeding
marine
growth?

I have no experience with this but I don't think this will work as
the small particles of copper would be surrounded by epoxy, protecting
the marine creatures from the toxic effect of the copper.

I have mixed powdered graphite (10%) in epoxy for the bottom of my
Microtrawler which lives on a trailer, as it makes a good UV shield
protecting the epoxy. It's easy to clean and when scratched a quick
wash, a light sanding and a dab of epoxy with 10% graphite and it's
good as new. No paint (or re-painting) needed, and the bonus is it
looks good.

Another epoxy additive I've used is aluminum powder, used in the
final or near final epoxy coats on the pilothouse roof followed by
primer and paint. The purpose is to block long-wave solar radiation
from penetrating the ply to reduce heat build-up. Course some of you
guys up north would probably want the heat. :)

Rick
Greetings, Bolgeristas! (just saw that somewhere in one of the recent
postings, and loved it!)

I'm gradually getting on course toward building a Micro this winter, mostly
for trailer sailing, as a short-term way of appeasing the bug Annie Hill's
book planted in my brain until I can get into a big liveaboard, hopefully
within 5 years..... hence the name I'm thinking of for my Micro is
'Shortcut'. Since I've been reading up on building a 30+-footer for several
years, I've been picking up tricks I want to use in my big boat and wonder
if one of them might be suited to a Micro that would initially be trailered
but perhaps eventually put on a mooring. I've heard of some copper powder
you can mix with epoxy and apply as a more lasting bottom treatment - has
anyone had any experience with this? Does it work at impeding marine growth?
And for the short term, if it's on a trailered boat, does it leach off in
the rain and turn your trailer, driveway, bottom of your boat, etc. green?
And what about electrolysis issues with rudder fittings, lead keel, or an
outboard you forgot to tip up while at mooring? Any info would be
appreciated....

thanks,

Paul



Paul Lefebvre
paul@...
I just kind of made up that sentence. I certainly am not an expert
on rot, boatbuilding or any of this stuff, but I am pretty sure I
read about deterioration of wood near metal fasteners, and I think it
was in the Wood Technology column that Peter refers to. Maybe it
isn't properly called rot, but a weakening of the material
surrounding the fastener. I don't know how long it takes, how severe
the problems, or which metals do what.

I'll see if I can dig up the article.

Frank

--- Inbolger@egroups.com, "Peter Vanderwaart" <pvanderw@o...> wrote:
> > Tell me more about this "metal induced rot". In many years of
> > reading everything about wooden boats that I could get my hands
on,
> I
> > have never seen the term used before.
>
> The Wood Technology column in WoodenBoat has covered this to some
> extent. I think that one of the problems is acidity in the wood
> reacting with the metal fastenings.
>
> Peter
> Tell me more about this "metal induced rot". In many years of
> reading everything about wooden boats that I could get my hands on,
I
> have never seen the term used before.

The Wood Technology column in WoodenBoat has covered this to some
extent. I think that one of the problems is acidity in the wood
reacting with the metal fastenings.

Peter
I should think as a Bolgerista, you'd know that you can find
inexpensive substitutes for all of this stuff. Will work fine almost
everywhere, except if you visit the waterfront near the Newport
mansions your boat will dissolve in embarassment. If you were a good
little consumer I wouldn't expect you to build your own boat.

Peel ply: not necessarily needed for a glue job, can use aircraft
dacron at less than 4 bucks a yard. Some people use plastic sheet
with
lots of tiny holes put in. Model airplane hobbyists sometimes use a
gadget that I forget the name of with a roller with spikes on it to
make lots of tiny holes.

"blankets": rags, paper towels, rope, newspaper, etc. Pretty much any
absorbent material
film: 4 or 6 mil plastic sheet is cheap at building supply places

Of course the real challenge is the vacuum pump. Once that's figured
the rest is easy.

But still, the 1/2" wood may be the best way to go.

Good luck with whatever you decide.

--- Inbolger@egroups.com, "Derek Waters" <dgw@d...> wrote:
snip
> ply for less than the cost of all the peel ply, blankets, films etc
> proffered by the local fibreglass supplier. snip
>
> Derek
Thank you all - lots of information.

After a weekend of tussling with glassed butt joints I'm feeling less brave
about tackling an entirely new (to me ) technique on the part of the boat
between me and Davy Jones...

Lots of holes and lots of screws seems to be the majority concensus.
Doubled quarter inch precludes using nails. Solid is appealing - after a bit
of calling around it appears I can buy 4 sheets of 1/2" 'waterproof' meranti
ply for less than the cost of all the peel ply, blankets, films etc
proffered by the local fibreglass supplier. Of course that would leave me
with eight spare sheets of 1/4" - four more dinghies :)

Derek
Frank,

Tell me more about this "metal induced rot". In many years of
reading everything about wooden boats that I could get my hands on, I
have never seen the term used before. Do you have a source? I've
owned
a couple of woooden boats fastened with a variety of metal screws,
bolts, etc. I never knew that the very metal that held them together
would "induce rot" I always thought that rot was caused by
microorganisms.

I have seen wooden structures where the fasteners had corroded away
even though the wood was sound.

Vince

--- Inbolger@egroups.com, "Frank San Miguel" <sanmi@c...> wrote:
> SBronze ring nails sounds like a good method too, but I'd worry
about
> metal induced rot over time.
>
> Frank
>
> --- Inbolger@egroups.com, "Harry W. James" <welshman@p...> wrote:
> > You can get a mechanical feel, also if you use the torque setting
> on your screw
> > gun or if you are using a screw shooter, you can set the depth
that
> the head
> > goes in before the clutch kicks out.
> >
> > HJ
> >
> > Chuck Leinweber wrote:
> >
> > > Richard:
> > >
> > > You're right, of course. It is possible to get a feel for when
> the first
> > > sheet spins out, and stop your drill before the second one
does.
> I guess I
> > > am just too timid to do that. Five minutes of drilling will
> guarantee a
> > > good clamp, so that is the way I do it. Filling the holes is
not
> that bad -
> > > get a putty knife and fill with a mix of peanut butter
> consistency, when
> > > set, smooth with a belt sander.
> > >
If you really needed to do this, then I think bagging would come into
its own. Instead of driving 100's of screws or nails you could just
drive 2 or 3 to keep each sheet from slipping, then bag it all at
once. Probably would want to have some really fast way of spreading
epoxy uniformly, and you'd probably want to use really slow epoxy.
Why
only 1/2" ply?
--- Inbolger@egroups.com, "Frank San Miguel" <sanmi@c...> wrote:
> So assuming you were building a hypothetical really big Bolger boat
> like Tahiti - How would you automate the process of creating a 60'
> sharpie bottom with six layers of 1/2" ply? How do you make it an
> assembly line process so that you can lay down 16 sheets in 8
hours?
>
> I'm thinking the best way is to build the first layer on its frame
> using butt blocks, then use drywall screws with no pre-drilled
holes
> for the remainder, but I would be worried about preventing voids.
> SBronze ring nails sounds like a good method too, but I'd worry
about
> metal induced rot over time.
>
> Frank
>
> --- Inbolger@egroups.com, "Harry W. James" <welshman@p...> wrote:
> > You can get a mechanical feel, also if you use the torque setting
> on your screw
> > gun or if you are using a screw shooter, you can set the depth
that
> the head
> > goes in before the clutch kicks out.
> >
> > HJ
> >
> > Chuck Leinweber wrote:
> >
> > > Richard:
> > >
> > > You're right, of course. It is possible to get a feel for when
> the first
> > > sheet spins out, and stop your drill before the second one
does.
> I guess I
> > > am just too timid to do that. Five minutes of drilling will
> guarantee a
> > > good clamp, so that is the way I do it. Filling the holes is
not
> that bad -
> > > get a putty knife and fill with a mix of peanut butter
> consistency, when
> > > set, smooth with a belt sander.
> > >
I'm on the side of the hole-drillers. I drilled because its easy to
overtighten and strip the inch ply, specially in 1/4 inch. I also used
round (or pan) headed screws as they don't distort the top layer of ply when
tightened.

On drywall screws generally, I've found that they are very brittle, and snap
off at awkward times. I switched to flooring screws for temporary
attachments and jig building, and have never broken one. The threads are
deep and are smoother than drywall screws. Finally, they take a Roberson
screwdriver bit (square hole) that almost never slips.

Jamie Orr

-----Original Message-----
From: Chuck Leinweber [mailto:chuck@...]
Sent: Saturday, August 26, 2000 9:08 PM
To:bolger@egroups.com
Subject: Re: [bolger] doubling ply bottoms


Richard:

You're right, of course. It is possible to get a feel for when the first
sheet spins out, and stop your drill before the second one does. I guess I
am just too timid to do that. Five minutes of drilling will guarantee a
good clamp, so that is the way I do it. Filling the holes is not that bad -
get a putty knife and fill with a mix of peanut butter consistency, when
set, smooth with a belt sander.

Chuck


> Chuck, I use drywall screws to clamp plywood all the time, and don't
> pre-drill. About the only time I find it nessicary to drill is when
clamping
> very thick pieces, say 2x stock, with 3" screws.
>
> What I do is run the screw in, then keep running it in until the head of
the
> screw has seated itself firmly in the top layer of plywood, then keep
> running it in until the pieces are clamped together.
>
> I just performed your experiment to figure out how this works. You are
> right, when the screw head pushs on the second piece of plywood, it
creates
> a gap. When the head of the screw stops on the top layer of ply, and you
> keep screwing, the threads in the top ply, under the head, have nothing to
> do but strip out. The threads on the other piece that the screw is in can
> still pull on that piece though, and pull the two together.
>
> The limiting factor of the method: If you can take one piece of your
> material, and you can't strip the screw out by overdriving it, say a 2x4
and
> a 3" drywall screw, then you need to pre-drill.
>
> Generaly, if you can't see the results, you will need to get a "feel" for
> it. In, push, strip, pull, snug. Did the hole bottom of my boat this way,
> screw every 4".




Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.
So assuming you were building a hypothetical really big Bolger boat
like Tahiti - How would you automate the process of creating a 60'
sharpie bottom with six layers of 1/2" ply? How do you make it an
assembly line process so that you can lay down 16 sheets in 8 hours?

I'm thinking the best way is to build the first layer on its frame
using butt blocks, then use drywall screws with no pre-drilled holes
for the remainder, but I would be worried about preventing voids.
SBronze ring nails sounds like a good method too, but I'd worry about
metal induced rot over time.

Frank

--- Inbolger@egroups.com, "Harry W. James" <welshman@p...> wrote:
> You can get a mechanical feel, also if you use the torque setting
on your screw
> gun or if you are using a screw shooter, you can set the depth that
the head
> goes in before the clutch kicks out.
>
> HJ
>
> Chuck Leinweber wrote:
>
> > Richard:
> >
> > You're right, of course. It is possible to get a feel for when
the first
> > sheet spins out, and stop your drill before the second one does.
I guess I
> > am just too timid to do that. Five minutes of drilling will
guarantee a
> > good clamp, so that is the way I do it. Filling the holes is not
that bad -
> > get a putty knife and fill with a mix of peanut butter
consistency, when
> > set, smooth with a belt sander.
> >
You can get a mechanical feel, also if you use the torque setting on your screw
gun or if you are using a screw shooter, you can set the depth that the head
goes in before the clutch kicks out.

HJ

Chuck Leinweber wrote:

> Richard:
>
> You're right, of course. It is possible to get a feel for when the first
> sheet spins out, and stop your drill before the second one does. I guess I
> am just too timid to do that. Five minutes of drilling will guarantee a
> good clamp, so that is the way I do it. Filling the holes is not that bad -
> get a putty knife and fill with a mix of peanut butter consistency, when
> set, smooth with a belt sander.
>
> Chuck
>
> > Chuck, I use drywall screws to clamp plywood all the time, and don't
> > pre-drill. About the only time I find it nessicary to drill is when
> clamping
> > very thick pieces, say 2x stock, with 3" screws.
> >
> > What I do is run the screw in, then keep running it in until the head of
> the
> > screw has seated itself firmly in the top layer of plywood, then keep
> > running it in until the pieces are clamped together.
> >
> > I just performed your experiment to figure out how this works. You are
> > right, when the screw head pushs on the second piece of plywood, it
> creates
> > a gap. When the head of the screw stops on the top layer of ply, and you
> > keep screwing, the threads in the top ply, under the head, have nothing to
> > do but strip out. The threads on the other piece that the screw is in can
> > still pull on that piece though, and pull the two together.
> >
> > The limiting factor of the method: If you can take one piece of your
> > material, and you can't strip the screw out by overdriving it, say a 2x4
> and
> > a 3" drywall screw, then you need to pre-drill.
> >
> > Generaly, if you can't see the results, you will need to get a "feel" for
> > it. In, push, strip, pull, snug. Did the hole bottom of my boat this way,
> > screw every 4".
>
>
> Bolger rules!!!
> - no cursing
> - stay on topic
> - use punctuation
> - add your comments at the TOP and SIGN your posts
> - add some content: send "thanks!" and "ditto!" posts off-list.




--

_ _ _ _ _
% Harrywelshman@...
Richard:

You're right, of course. It is possible to get a feel for when the first
sheet spins out, and stop your drill before the second one does. I guess I
am just too timid to do that. Five minutes of drilling will guarantee a
good clamp, so that is the way I do it. Filling the holes is not that bad -
get a putty knife and fill with a mix of peanut butter consistency, when
set, smooth with a belt sander.

Chuck


> Chuck, I use drywall screws to clamp plywood all the time, and don't
> pre-drill. About the only time I find it nessicary to drill is when
clamping
> very thick pieces, say 2x stock, with 3" screws.
>
> What I do is run the screw in, then keep running it in until the head of
the
> screw has seated itself firmly in the top layer of plywood, then keep
> running it in until the pieces are clamped together.
>
> I just performed your experiment to figure out how this works. You are
> right, when the screw head pushs on the second piece of plywood, it
creates
> a gap. When the head of the screw stops on the top layer of ply, and you
> keep screwing, the threads in the top ply, under the head, have nothing to
> do but strip out. The threads on the other piece that the screw is in can
> still pull on that piece though, and pull the two together.
>
> The limiting factor of the method: If you can take one piece of your
> material, and you can't strip the screw out by overdriving it, say a 2x4
and
> a 3" drywall screw, then you need to pre-drill.
>
> Generaly, if you can't see the results, you will need to get a "feel" for
> it. In, push, strip, pull, snug. Did the hole bottom of my boat this way,
> screw every 4".
Chuck, I use drywall screws to clamp plywood all the time, and don't
pre-drill. About the only time I find it nessicary to drill is when clamping
very thick pieces, say 2x stock, with 3" screws.

What I do is run the screw in, then keep running it in until the head of the
screw has seated itself firmly in the top layer of plywood, then keep
running it in until the pieces are clamped together.

I just performed your experiment to figure out how this works. You are
right, when the screw head pushs on the second piece of plywood, it creates
a gap. When the head of the screw stops on the top layer of ply, and you
keep screwing, the threads in the top ply, under the head, have nothing to
do but strip out. The threads on the other piece that the screw is in can
still pull on that piece though, and pull the two together.

The limiting factor of the method: If you can take one piece of your
material, and you can't strip the screw out by overdriving it, say a 2x4 and
a 3" drywall screw, then you need to pre-drill.

Generaly, if you can't see the results, you will need to get a "feel" for
it. In, push, strip, pull, snug. Did the hole bottom of my boat this way,
screw every 4".

> Hi Harry:
>
> The reason I drill holes is to allow the screws to pull the two pieces of
> ply together. Do this experiment: Take two pieces of scrap ply, and
clamp
> them in a vice. Now start a drywall screw into one of the pieces. As
soon
> as it gets through the first piece, it will push the second piece slightly
> away until it can start into it. When the head comes to the first piece,
> the screw will stop, and the two pieces will be held slightly apart. If
you
> keep screwing, the threads may(depending on the thickness of the ply) spin
> out in the first sheet of ply resulting in the two sheets pulling
together.
> If you can see this taking place, you can stop at the precise moment that
> the two contact, otherwise, the screw will spin out in the second piece of
> ply, and the screw will be loose in the hole, and useless.
>
> If you drill a hole slightly larger than the threads of the screw in the
> first piece of ply, then put the screw through that hole and start it into
> the second piece, when it is tightened completely, the two pieces of wood
> will be pulled together like a clamp.
>
> Chuck
>
>
> > Chuck
> >
> > How come you are drilling holes? The hole point ( I love it when
> > I get one off like that) of sheet rock screws is you don't have
> > to drill a hole. I use what the pros use, a Milwaukee screw
> > shooter. The pros can shot 25-30 screws a minute , and I can do
> > 10 -15. You can pull them even faster. The most time consuming
> > thing should be the spreading of the glue. I see that somebody
> > else suggested a notched trowel , the only way to get consistency
> > in spreading. You can make your own throw away one by notching a
> > plastic spreader with a triangular file.
> >
> > Chuck Leinweber wrote:
> >
> > > Derek: I have laminated the bottoms of three boats now. Each
> > > time, I used the "drywall screw and remove" method. I have to
> > > admit that I was never entirely happy with this process, but I
> > > keep doing it again. You have to remember to drill holes in
> > > the top layer big enough to pass the screw shanks so that they
> > > will pull the two layers together. I don't think that
> > > squeezing out the resin is the problem, squeezing out the air
> > > is, though. The big problem is the time it takes: drilling ten
> > > thousand holes, screwing ten thousand screws, unscrewing
> > > ten.... If you are laminating the bottom right on the boat, I
> > > don't think vacuum bagging would work, as you could only get
> > > pressure on one side. If I were doing it again, I would be
> > > tempted to start with full thickness ply (if bending is not a
> > > problem) and do real good glass butt joints.
> >
> >
> >
> > Bolger rules!!!
> > - no cursing
> > - stay on topic
> > - use punctuation
> > - add your comments at the TOP and SIGN your posts
> > - add some content: send "thanks!" and "ditto!" posts off-list.
> >
> >
>
>
>
> Bolger rules!!!
> - no cursing
> - stay on topic
> - use punctuation
> - add your comments at the TOP and SIGN your posts
> - add some content: send "thanks!" and "ditto!" posts off-list.
>
Hi Harry:

The reason I drill holes is to allow the screws to pull the two pieces of
ply together. Do this experiment: Take two pieces of scrap ply, and clamp
them in a vice. Now start a drywall screw into one of the pieces. As soon
as it gets through the first piece, it will push the second piece slightly
away until it can start into it. When the head comes to the first piece,
the screw will stop, and the two pieces will be held slightly apart. If you
keep screwing, the threads may(depending on the thickness of the ply) spin
out in the first sheet of ply resulting in the two sheets pulling together.
If you can see this taking place, you can stop at the precise moment that
the two contact, otherwise, the screw will spin out in the second piece of
ply, and the screw will be loose in the hole, and useless.

If you drill a hole slightly larger than the threads of the screw in the
first piece of ply, then put the screw through that hole and start it into
the second piece, when it is tightened completely, the two pieces of wood
will be pulled together like a clamp.

Chuck


> Chuck
>
> How come you are drilling holes? The hole point ( I love it when
> I get one off like that) of sheet rock screws is you don't have
> to drill a hole. I use what the pros use, a Milwaukee screw
> shooter. The pros can shot 25-30 screws a minute , and I can do
> 10 -15. You can pull them even faster. The most time consuming
> thing should be the spreading of the glue. I see that somebody
> else suggested a notched trowel , the only way to get consistency
> in spreading. You can make your own throw away one by notching a
> plastic spreader with a triangular file.
>
> Chuck Leinweber wrote:
>
> > Derek: I have laminated the bottoms of three boats now. Each
> > time, I used the "drywall screw and remove" method. I have to
> > admit that I was never entirely happy with this process, but I
> > keep doing it again. You have to remember to drill holes in
> > the top layer big enough to pass the screw shanks so that they
> > will pull the two layers together. I don't think that
> > squeezing out the resin is the problem, squeezing out the air
> > is, though. The big problem is the time it takes: drilling ten
> > thousand holes, screwing ten thousand screws, unscrewing
> > ten.... If you are laminating the bottom right on the boat, I
> > don't think vacuum bagging would work, as you could only get
> > pressure on one side. If I were doing it again, I would be
> > tempted to start with full thickness ply (if bending is not a
> > problem) and do real good glass butt joints.
>
>
>
> Bolger rules!!!
> - no cursing
> - stay on topic
> - use punctuation
> - add your comments at the TOP and SIGN your posts
> - add some content: send "thanks!" and "ditto!" posts off-list.
>
>
Chuck

How come you are drilling holes? The hole point ( I love it when
I get one off like that) of sheet rock screws is you don't have
to drill a hole. I use what the pros use, a Milwaukee screw
shooter. The pros can shot 25-30 screws a minute , and I can do
10 -15. You can pull them even faster. The most time consuming
thing should be the spreading of the glue. I see that somebody
else suggested a notched trowel , the only way to get consistency
in spreading. You can make your own throw away one by notching a
plastic spreader with a triangular file.

Chuck Leinweber wrote:

> Derek: I have laminated the bottoms of three boats now. Each
> time, I used the "drywall screw and remove" method. I have to
> admit that I was never entirely happy with this process, but I
> keep doing it again. You have to remember to drill holes in
> the top layer big enough to pass the screw shanks so that they
> will pull the two layers together. I don't think that
> squeezing out the resin is the problem, squeezing out the air
> is, though. The big problem is the time it takes: drilling ten
> thousand holes, screwing ten thousand screws, unscrewing
> ten.... If you are laminating the bottom right on the boat, I
> don't think vacuum bagging would work, as you could only get
> pressure on one side. If I were doing it again, I would be
> tempted to start with full thickness ply (if bending is not a
> problem) and do real good glass butt joints.
In a message dated 8/25/2000 1:41:33 PM Eastern Daylight Time,
chuck@...writes:

<< Steve:

Did you have someone backing you up (holding a hammer on the other side)?
Did the nails come through where you had to grind them off?
>>

Mj has two 1/2 inch layers of plywood - it was plenty stiff with no need for
a back up - I used nails small enough so that they didn't come thru ( less
than one inch) . It worked fine. I put them pretty close - about 6 inches
apart. It was just like shingling a roof. Very easy. Steve
Just cover it with a piece of screen and then a piece of plastic and tape
the edges and the seems
and you can get a real good seal.

You would need a bigger pump than a refrigerator compressor. An automobile
airconditioner compressor on a 1 hp motor and a 50 or 100 gallon propane
tank for a vacuum tank would be a good starting point. A couple of shop
vacs to get things started would be handy.

All the pump needs to do is take care of leaks and out gassing. So if
everything was just right a compressor out of a house sized refrigerator
would do it. But I don't trust theory that much.

The problem comes when the glue starts to kick and you develop a leak and
need some reserve to catch up.

Gordon
Gordon Cougergcouger@...
Stillwater, OK www.couger.com/gcouger
405 624-2855 GMT -6:00
From: "Chuck Leinweber" <chuck@...>

Lincoln and Wade:

OK, this all makes sense, but over a large area, say a 30' x 8' boat
bottom, how airtight can you really get the seal? How big a pump do you
need?

Chuck


You don't really have to do a vacuum _bag_, you can do a vacuum sheet.
Say you want to laminate a small piece of plywood onto a big piece.
Slather on the glue, slap em together, and cover the small sheet with a
rubber sheet w/ vacuum hose attached. Tape the edges of the rubber sheet
down onto the big piece and suck the air out.
Derek,
On my Martha Jane I used drywall screws to attach the first layer and an air powered staple gun with narrow alloy crown staples
for the second layer.. I WAS  going to use ring shank nails but found ,working by myself, that the nail method took longer and needed both hands.
In my tests I found the holding power of the staples to be equivalent to ring shank nails, I could fire off one per second and by adjusting the air pressure the staples ended up just below the surface ,easy to fill and fair before glassing
 
As for using balsa strips to stop too much epoxy squeezing out....I don't like the sound of that.
How thick does the glue join need to be ?
By using the self leveling ability of slightly thickened epoxy between two smooth surfaces (plywood) only moderate pressure is required to get a uniform glue line
When laminating I roll a coat of straight epoxy ontobothsurfaces and let it stand a while to be absorbed by the timber,
then apply aslightlythickened epoxy mixture with a notched squeege.
By standing in the centre of the sheet and working out towards the edges, fastening as I go I believe I avoid the voids.
 
I have never tried vacuum bagging
 
Thats my two bobs worth
Regards,
Tony Walker
----- Original Message -----
Sent:Friday, August 25, 2000 3:31 PM
Subject:[bolger] doubling ply bottoms

Hi Group
 
How have members clamped and glued double skinned ply bottoms? At present I'm leaning towards using the drywall screw clamping method for the first layer, and vacuum bagging on a second layer - a process with which I have zero experience.
 
I'd love to hear success (and failure) stories, alternative methods, etc. Somewhere (on the group?) I read about someone using strip balsa to ensure the epoxy didn't get squeezed out entirely....
 
Derek

Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.
Okay, I've only done 24' X 3' or so, and a complicated shape maybe
10'
X 6', but I think if you were working solo, you wouldn't want to do
too many sheets of plywood at one time so the epoxy didn't all go off
too soon.

To pull down the bag at first, you can use a vacuum cleaner. In fact,
if you've got a reliable one you could probably use it for the whole
job. Once the bag is mostly pulled down, you can use something
smaller. If it's quiet, you can hear the leaks. With a vacuum cleaner
you may not need to find the leaks. I don't know exactly what size
pump you need. If you're real good at sealing everything up it could
be a very small pump, but this can be hard to achieve.

I would do a test on something non-critical before I'd do it on the
boat. I'd do that If I were using ring nails, too. I'd want to cut it
up afterwards to make sure there were no voids. You might put a few
small holes in the wood to help the air get out.

If you have an air compressor, I understand there are vacuum "pump"
gadgets that are cheap and small that work off compressed air.
Basically some kind of venturi valve.
--- Inbolger@egroups.com, "Chuck Leinweber" <chuck@d...> wrote:
> Lincoln and Wade:
>
> OK, this all makes sense, but over a large area, say a 30' x 8'
boat
bottom, how airtight can you really get the seal? How big a pump do
you need?
>
> Chuck
>
>
> You don't really have to do a vacuum _bag_, you can do a vacuum
sheet. Say you want to laminate a small piece of plywood onto a big
piece. Slather on the glue, slap em together, and cover the small
sheet with a rubber sheet w/ vacuum hose attached. Tape the edges of
the rubber sheet down onto the big piece and suck the air out.
Chuck Leinweber wrote:

> OK, this all makes sense, but over a large area, say a 30' x 8' boat
> bottom, how airtight can you really get the seal? How big a pump do
> you need?

I don't think getting the edges sealed would be that big a problem, and
as long as the pump can empty your "bag" / sheet within your epoxy
window it would do it. If it wont, you don't need a bigger pump, you can
store vacuum like compressors store compressed air. Pull a vacuum on a
tank to begin with, then when you turn your lever... "hey man.....this
sucks!"
I vote for ring nails!
David

SOME CLICKS THAT COUNT!!
Feed someone.
http://www.thehungersite.com/
Save a little rain forest.
http://rainforest.care2.com/front.html/player12296

Simplicity Boats (& mirror sites)
http://members.tripod.com/simplicityboats/index.html
http://members.xoom.com/simpleboats/index.html
Here's my latest boat:
http://members.tripod.com/simplicityboats/summerbreeze.html
http://members.xoom.com/simpleboats/summerbreeze.html
Quasi esoteric musical instruments
http://unicornstrings.com
Steve:

Did you have someone backing you up (holding a hammer on the other side)?
Did the nails come through where you had to grind them off?

Chuck


> All this vaccum bagging sounds so complicated - my ring shank nails were
so
> easy - Just pound them in and leave them - but start at the center and
work
> out to the edges. Steve Anderson
Wade Leftwich wrote:
>
>If the edges seal down tight before the center can get
evacuated, then you have a soft spot.

All I know about vacuum bagging I learned from Jim Brown's
WB article, "Bagging the Gull." He suggests a plastic
window screen 'airway' between layers of polyfilm to
prevent this problem.

A flat bottom boat would have a very easily tailored 'bag' I
think. But nothing could be easier than using full thickness
ply if you can (cf. Chuck).

Mark
"How to build any boat the stitch and glue way" by Samual Devlin, or something
like that. Really good book, I've gone over it many times. He described
drilling lots of holes, but only putting a pan-head screw in every other one,
allowing the air and excess epoxy to smush out the other holes. That's
basically how I plan on doing it on my micro, which will have double 3/8"
bottoms. (Hopefully, I'll be doing bottom work within 2 weeks!!!!!) Yes, I
will remove the screws after everything set's up (but those ring shank nails do
sound pretty tempting ;-)

Glen






"Orr, Jamie" <jorr@...> on 08/25/2000 08:36:59 AM

Please respond tobolger@egroups.com

Sent by: "Orr, Jamie" <jorr@...>


To: "'bolger @egroups.com'" <bolger@egroups.com>
cc: (Glen Gibson/HQ/3Com)
Subject: RE: [bolger] doubling ply bottoms



I used double 1/4 inch ply on the bilge panels of my Chebacco. I described
how I did it in Bill Samson's Chebacco News -- forget which issue. It
worked very well and went together easily -- the finished bilge panels were
from 24 to 30 inches wide and 20 feet long. My method was based on
Devlin's, given in his boat building book, I forget the name.

Jamie Orr

-----Original Message-----
From: Derek Waters [mailto:dgw@...]
Sent: Thursday, August 24, 2000 10:31 PM
To: bolger group
Subject: [bolger] doubling ply bottoms


Hi Group

How have members clamped and glued double skinned ply bottoms? At present
I'm leaning towards using the drywall screw clamping method for the first
layer, and vacuum bagging on a second layer - a process with which I have
zero experience.

I'd love to hear success (and failure) stories, alternative methods, etc.
Somewhere (on the group?) I read about someone using strip balsa to ensure
the epoxy didn't get squeezed out entirely....

Derek
_____

<http://click.egroups.com/1/7525/13/_/3457/_/967186034/>

<http://adimg.egroups.com/img/7525/13/_/3457/_/967186034/468x60_Bubbles.gif>


_____


Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.




Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.
I used double 1/4 inch ply on the bilge panels of my Chebacco. I described
how I did it in Bill Samson's Chebacco News -- forget which issue. It
worked very well and went together easily -- the finished bilge panels were
from 24 to 30 inches wide and 20 feet long. My method was based on
Devlin's, given in his boat building book, I forget the name.

Jamie Orr

-----Original Message-----
From: Derek Waters [mailto:dgw@...]
Sent: Thursday, August 24, 2000 10:31 PM
To: bolger group
Subject: [bolger] doubling ply bottoms


Hi Group

How have members clamped and glued double skinned ply bottoms? At present
I'm leaning towards using the drywall screw clamping method for the first
layer, and vacuum bagging on a second layer - a process with which I have
zero experience.

I'd love to hear success (and failure) stories, alternative methods, etc.
Somewhere (on the group?) I read about someone using strip balsa to ensure
the epoxy didn't get squeezed out entirely....

Derek
_____

<http://click.egroups.com/1/7525/13/_/3457/_/967186034/>

<http://adimg.egroups.com/img/7525/13/_/3457/_/967186034/468x60_Bubbles.gif>


_____


Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.
> Oh, you want to get _practical_ !

> > All this vaccum bagging sounds so complicated - my ring shank
> > nails were so
> > easy -

I think the words 'vacuum bagging' add 20% to the price in a For Sale
ad.

That mere 1 atmosphere is like putting a 14lb weight on each square
inch or a 2000lb weight on each sq ft.

PHV
In a message dated 8/25/2000 10:35:02 AM Eastern Daylight Time,
wade@...writes:

<< Oh, you want to get _practical_ ! >>

( Ring shank nails) not just practical! Think of the added ballast! So much
on the minds of martha jane builders! Steve
Oh, you want to get _practical_ !

> -----Original Message-----
> From:hwal@...[mailto:hwal@...]
> Sent: Friday, August 25, 2000 10:31 AM
> To:bolger@egroups.com
> Subject: Re: [bolger] doubling ply bottoms
>
>
> All this vaccum bagging sounds so complicated - my ring shank
> nails were so
> easy - Just pound them in and leave them - but start at the
> center and work
> out to the edges. Steve Anderson
>
>
> Bolger rules!!!
> - no cursing
> - stay on topic
> - use punctuation
> - add your comments at the TOP and SIGN your posts
> - add some content: send "thanks!" and "ditto!" posts off-list.
>
The aircraft builder linked to earlier in this thread has a pump he made for $25 and a junked A/C compressor. Remember, you're not making pressure here -- the most pressure you're ever going to get is 1 atmosphere.
 
Actually I think the limiting factors on how big a piece of plywood you can laminate are the stiffness and the area. If the edges seal down tight before the center can get evacuated, then you have a soft spot.  That's not an issue with vacuum bagging glass layup, because it's all squishy when you start the pump.
 
On the plus side, when laminating plywood you don't even need a sheet to cover the whole piece, you just need to seal the edges and make sure you have a continues air gap all the way around the edge inside the vacuum sheet.
 
-----Original Message-----
From:Chuck Leinweber [mailto:chuck@...]
Sent:Friday, August 25, 2000 10:01 AM
To:bolger@egroups.com
Subject:Re: [bolger] doubling ply bottoms

Lincoln and Wade:
 
OK, this all makes sense, but over a large area, say a 30' x 8' boat bottom, how airtight can you really get the seal?  How big a pump do you need?
 
Chuck

You don't really have to do a vacuum _bag_, you can do a vacuum sheet. Say you want to laminate a small piece of plywood onto a big piece. Slather on the glue, slap em together, and cover the small sheet with a rubber sheet w/ vacuum hose attached. Tape the edges of the rubber sheet down onto the big piece and suck the air out.
 
 
 
 

Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.
All this vaccum bagging sounds so complicated - my ring shank nails were so
easy - Just pound them in and leave them - but start at the center and work
out to the edges. Steve Anderson
Lincoln and Wade:
 
OK, this all makes sense, but over a large area, say a 30' x 8' boat bottom, how airtight can you really get the seal?  How big a pump do you need?
 
Chuck

You don't really have to do a vacuum _bag_, you can do a vacuum sheet. Say you want to laminate a small piece of plywood onto a big piece. Slather on the glue, slap em together, and cover the small sheet with a rubber sheet w/ vacuum hose attached. Tape the edges of the rubber sheet down onto the big piece and suck the air out.
 
 
 
 
assuming the first layer of the bottom is water and airproof, you
just
use the first layer of plywood as one side of the bag. When I helped
a
(semi) professional boat builder bag glass boats, he used a mold as
one side of the bag. Works great.
--- Inbolger@egroups.com, "Chuck Leinweber" <chuck@d...> wrote:
>
> >> I don't think vacuum bagging would work, as you could only get
pressure on one side.
>
> >If you can pull the air out of the interface, I think the
atmosphere will take care of applying pressure to both sides.
>
> How would you do this without bagging the entire boat?
>
> Chuck
You don't really have to do a vacuum _bag_, you can do a vacuum sheet. Say you want to laminate a small piece of plywood onto a big piece. Slather on the glue, slap em together, and cover the small sheet with a rubber sheet w/ vacuum hose attached. Tape the edges of the rubber sheet down onto the big piece and suck the air out.
 
 
 
 -----Original Message-----
From:Chuck Leinweber [mailto:chuck@...]
Sent:Friday, August 25, 2000 9:10 AM
To:bolger@egroups.com
Subject:Re: [bolger] doubling ply bottoms

 
>>I don't think vacuum bagging would work, as you could only get pressure on one side. 
 
>If you can pull the air out of the interface, I think the atmosphere will take care of applying pressure to both sides.
 
How would you do this without bagging the entire boat?
 
Chuck

Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.
 
>>I don't think vacuum bagging would work, as you could only get pressure on one side. 
 
>If you can pull the air out of the interface, I think the atmosphere will take care of applying pressure to both sides.
 
How would you do this without bagging the entire boat?
 
Chuck
>>I don't think vacuum bagging would work, as you could only get pressure on one side. 
 
If you can pull the air out of the interface, I think the atmosphere will take care of applying pressure to both sides.
 
 
 
 
Derek:
 
I have laminated the bottoms of three boats now.  Each time, I used the "drywall screw and remove" method.  I have to admit that I was never entirely happy with this process, but I keep doing it again.  You have to remember to drill holes in the top layer big enough to pass the screw shanks so that they will pull the two layers together.  I don't think that squeezing out the resin is the problem, squeezing out the air is, though. The big problem is the time it takes:  drilling ten thousand holes, screwing ten thousand screws, unscrewing ten.... If you are laminating the bottom right on the boat, I don't think vacuum bagging would work, as you could only get pressure on one side.  If I were doing it again, I would be tempted to start with full thickness ply (if bending is not a problem) and do real good glass butt joints.
 
I hope this helps.
 
Chuck
----- Original Message -----
Sent:Friday, August 25, 2000 12:31 AM
Subject:[bolger] doubling ply bottoms

Hi Group
 
How have members clamped and glued double skinned ply bottoms? At present I'm leaning towards using the drywall screw clamping method for the first layer, and vacuum bagging on a second layer - a process with which I have zero experience.
 
I'd love to hear success (and failure) stories, alternative methods, etc. Somewhere (on the group?) I read about someone using strip balsa to ensure the epoxy didn't get squeezed out entirely....
 
Derek

Bolger rules!!!
- no cursing
- stay on topic
- use punctuation
- add your comments at the TOP and SIGN your posts
- add some content: send "thanks!" and "ditto!" posts off-list.
Derek - I used bronze ringshank nails and glassed over them. Steve
Derek,
In case it helps... here are plans for cheap vacuum pump.
http://web2.airmail.net/redmonj/sucker.htm
david

Derek Waters wrote:

> Hi Group How have members clamped and glued double skinned ply
> bottoms? At present I'm leaning towards using the drywall screw
> clamping method for the first layer, and vacuum bagging on a second
> layer - a process with which I have zero experience. I'd love to hear
> success (and failure) stories, alternative methods, etc. Somewhere (on
> the group?) I read about someone using strip balsa to ensure the epoxy
> didn't get squeezed out entirely.... Derek
> -----------------------------------------------------------------------
>
> -----------------------------------------------------------------------
>
> Bolger rules!!!
> - no cursing
> - stay on topic
> - use punctuation
> - add your comments at the TOP and SIGN your posts
> - add some content: send "thanks!" and "ditto!" posts off-list.

--

SOME CLICKS THAT COUNT!!
Feed someone.
http://www.thehungersite.com/
Save a little rain forest.
http://rainforest.care2.com/front.html/player12296

Simplicity Boats (& mirror sites)
http://members.tripod.com/simplicityboats/index.html
http://members.xoom.com/simpleboats/index.html
Here's my latest boat:
http://members.tripod.com/simplicityboats/summerbreeze.html
http://members.xoom.com/simpleboats/summerbreeze.html
Quasi esoteric musical instruments
http://unicornstrings.com
I guress thats the beauty of dories and sharpies,
you can have a solid bottom w/o doubling
Jeff
ps Gentle reminder..arn't we supposed to stay in
Plain Text? Lotsa HTML lately, im guilty too.