[bolger] Re: Square Scarfs
Robert N. Lundy wrote:
thickened epoxy and sanding. On the inside I gave up and just sanded a
little.
best I could. I don't think its makes much difference with the 1/4"
ply. It was tricky holding the forward and aft molds close to the lines
while driving screws in to hold them in place.
> To Michael:In the end yes, but it required quite a few cycles of reapplying
>
> So you ended up using the "fiberglass buttstrap" I've seen described in your
> sides? That looks like it would finish off nice and clean.
thickened epoxy and sanding. On the inside I gave up and just sanded a
little.
>I believe I centered the plywood portion of the mold on the lines as
> One thing I keep staring at the plans and the key (and Payson's book)
> without figuring out. The miships mold (temporary) is to be positioned on
> the line scibed on the sides during building. Does this mean directly
> centered? should the mold be aft of the line of forward of it?
>
best I could. I don't think its makes much difference with the 1/4"
ply. It was tricky holding the forward and aft molds close to the lines
while driving screws in to hold them in place.
> thanks for your help Michael.
>
> Robert Lundy
> St. Petersburg, Fla.
>
> > -----Original Message-----
> > From: GHC [mailto:ghartc@...]
> > Sent: 05 October, 1999 6:13 PM
> > To:bolger@egroups.com
> > Subject: [bolger] Re: Square Scarfs
> >
> >
> > That's just what I did on the 3/4" bottom of my sneakeasy, with no
> > complaint...
> >
> > Gregg Carlson
> >
> > At 03:26 PM 10/4/1999 -0400, you wrote:
> > > "" bottom in the plan (but I would have to cough up for an extra
> > >sheet of plywood), I've been trying to think of a better way to
> > make my two
> > >8' sheets one long sheetwithout using a buttstrap plywood
> > scarfed in
> > >this manner. Comments from any more experienced woodworkers are most
> > >appreciated. Ha, Ha. & Amy Lundy
> > >St. Petersburg, Fla.
> > > Click Here! eGroups.com home:
> >http://www.egroups.com/group/bolger
> > > www.egroups.com - Simplifying group communications
> > >
> >
> >
> > ------------------------------------------------------------------------
> >
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> >
> >
> >
> >
>
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I use taped joints on my boat with good results. Where I did not
hollow out the seam with a belt sander it took a lot more work to get
them feathered out to look good but where they where hollowed slightly,
they basically have disappeared. Much like sheet rock finishing. So
far strength is not an issue since I firmly believe that on up to 1/2"
stock, the layered tape seams are by far stronger than the ply.
The easiest way I have found to build is to cover a 2x6 with plastic
wrap and screw the two sheets down tight to form a smooth seam, then
using thickened epoxy, coat and fill the seam except where the screws
are placed. The next day when set, remove the screws and finish one
side by sanding a slight hollow in the seam and lay in the tape. When
set, flip and do the other side.
This all takes 3 days to do properly so it is slower but does work
nicely.
When I stiched my boat together, I used this method also. I placed my
stiches about 2" apart, aligned the boat and filled between the stiches
with thickened epoxy, when set I cut the stiches out and removed. At
this point the boat is held together by the epoxy so don't try moving
anything, then fill in the gaps left by the stiches with thickened
epoxy. After this, finish the seams normally.
This way I have no stiches buried in the epoxy. It is slower but
easier. Just remember to remove the excess epoxy that may be squeezed
out on the inside as you do this, or suffer the sanding job later.
hollow out the seam with a belt sander it took a lot more work to get
them feathered out to look good but where they where hollowed slightly,
they basically have disappeared. Much like sheet rock finishing. So
far strength is not an issue since I firmly believe that on up to 1/2"
stock, the layered tape seams are by far stronger than the ply.
The easiest way I have found to build is to cover a 2x6 with plastic
wrap and screw the two sheets down tight to form a smooth seam, then
using thickened epoxy, coat and fill the seam except where the screws
are placed. The next day when set, remove the screws and finish one
side by sanding a slight hollow in the seam and lay in the tape. When
set, flip and do the other side.
This all takes 3 days to do properly so it is slower but does work
nicely.
When I stiched my boat together, I used this method also. I placed my
stiches about 2" apart, aligned the boat and filled between the stiches
with thickened epoxy, when set I cut the stiches out and removed. At
this point the boat is held together by the epoxy so don't try moving
anything, then fill in the gaps left by the stiches with thickened
epoxy. After this, finish the seams normally.
This way I have no stiches buried in the epoxy. It is slower but
easier. Just remember to remove the excess epoxy that may be squeezed
out on the inside as you do this, or suffer the sanding job later.
No, the bottom of the step of the Sneakeasy is 3/4", and the rest of the
bottom is 1/2". The sides were supposed to be 3/8", but I accidentally
used used 1/4" for some reason - could be that I blew up the plans from the
book...
I built the boat to run down the Arkansas River navigation channel. When
the water runs (and I mean 12-14 knots), I've seen plenty of trees, cows,
and once even a tractor-trailor and a Winnebago. That's tough on your bottom.
Damming the Arkansas was the biggest Corps project ever in the 70's - Will
Rogers said it could never be done.
Curious you asked about the fish - no - they don't carry (yet), but WE do
fish with guns in Oklahoma...
Gregg
At 06:46 PM 10/5/1999 -0400, you wrote:
bottom is 1/2". The sides were supposed to be 3/8", but I accidentally
used used 1/4" for some reason - could be that I blew up the plans from the
book...
I built the boat to run down the Arkansas River navigation channel. When
the water runs (and I mean 12-14 knots), I've seen plenty of trees, cows,
and once even a tractor-trailor and a Winnebago. That's tough on your bottom.
Damming the Arkansas was the biggest Corps project ever in the 70's - Will
Rogers said it could never be done.
Curious you asked about the fish - no - they don't carry (yet), but WE do
fish with guns in Oklahoma...
Gregg
At 06:46 PM 10/5/1999 -0400, you wrote:
>To Gregg:
>
>Did you use any type of formula to determine how far back to make the lap?
>
>A 3/4 in. bottom on a Sneakeasy? Do the fish in Oklahoma lakes have
>shotguns? Don't you think you should write an article for WoodenBoat about
>"Square Scarfs"? Really, if this works, you'd almost be better off having
>two of the lap joints in one of bolger's 16' boats and avoid the ugliness of
>a buttstrap all together.
>
>Thanks Gregg
>
>To Michael:
>
>So you ended up using the "fiberglass buttstrap" I've seen described in your
>sides? That looks like it would finish off nice and clean.
>
>One thing I keep staring at the plans and the key (and Payson's book)
>without figuring out. The miships mold (temporary) is to be positioned on
>the line scibed on the sides during building. Does this mean directly
>centered? should the mold be aft of the line of forward of it?
>
>thanks for your help Michael.
>
>Robert Lundy
>St. Petersburg, Fla.
>
>
>> -----Original Message-----
>> From: GHC [mailto:ghartc@...]
>> Sent: 05 October, 1999 6:13 PM
>> To:bolger@egroups.com
>> Subject: [bolger] Re: Square Scarfs
>>
>>
>> That's just what I did on the 3/4" bottom of my sneakeasy, with no
>> complaint...
>>
>> Gregg Carlson
>>
>> At 03:26 PM 10/4/1999 -0400, you wrote:
>> > "" bottom in the plan (but I would have to cough up for an extra
>> >sheet of plywood), I've been trying to think of a better way to
>> make my two
>> >8' sheets one long sheetwithout using a buttstrap plywood
>> scarfed in
>> >this manner. Comments from any more experienced woodworkers are most
>> >appreciated. Ha, Ha. & Amy Lundy
>> >St. Petersburg, Fla.
>> > Click Here! eGroups.com home:
>>http://www.egroups.com/group/bolger
>> > www.egroups.com - Simplifying group communications
>> >
>>
>>
>> ------------------------------------------------------------------------
>>
>> eGroups.com home:http://www.egroups.com/group/bolger
>>http://www.egroups.com- Simplifying group communications
>>
>>
>>
>>
>
>
>------------------------------------------------------------------------
>
>eGroups.com home:http://www.egroups.com/group/bolger
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>
>
>
>
>
jeff@...wrote:
epoxy prime pieces to be joined. (I used 1:1 thinned 50% with acetone)
lay down piece of particle board at least 12 inches wide
cover with wax paper
wet where joint will be with epoxy, lay glass in epoxy, wet glass out
attach one of the pieces to be spiced to particle board, centered over
glass, tack in place
apply wood flower or wheat flour thickened epoxy to edge
lay other piece to be spliced on glass and push into thickened filler, tack
in place
epoxy and glass top side
appy wax paper
apply 12 wide piece of particle board, tack in place
repeat if you have more pieces
hold long boards up with scrap wood
apply weight, lots of weight, evenly distributed
This is pure Payson and Carnell. Works very well, and Dave has done testing
that showes that very narrow strips of tape, 2 to 3 inches, is still
stronger than the wood.
I have done four joints at once, takes 24 hours to cure good. If you are
going to put lots of stress on it soon, you might give a day or so to set up
harder.
without the wires getting in the way.
> The easiest way I have found to build is to cover a 2x6 with plasticI do this:
> wrap and screw the two sheets down tight to form a smooth seam, then
> using thickened epoxy, coat and fill the seam except where the screws
> are placed. The next day when set, remove the screws and finish one
> side by sanding a slight hollow in the seam and lay in the tape. When
> set, flip and do the other side.
>
> This all takes 3 days to do properly so it is slower but does work
> nicely.
>
epoxy prime pieces to be joined. (I used 1:1 thinned 50% with acetone)
lay down piece of particle board at least 12 inches wide
cover with wax paper
wet where joint will be with epoxy, lay glass in epoxy, wet glass out
attach one of the pieces to be spiced to particle board, centered over
glass, tack in place
apply wood flower or wheat flour thickened epoxy to edge
lay other piece to be spliced on glass and push into thickened filler, tack
in place
epoxy and glass top side
appy wax paper
apply 12 wide piece of particle board, tack in place
repeat if you have more pieces
hold long boards up with scrap wood
apply weight, lots of weight, evenly distributed
This is pure Payson and Carnell. Works very well, and Dave has done testing
that showes that very narrow strips of tape, 2 to 3 inches, is still
stronger than the wood.
I have done four joints at once, takes 24 hours to cure good. If you are
going to put lots of stress on it soon, you might give a day or so to set up
harder.
>I do exactly the same thing, mainly so I can make reasonably sized fillets
> When I stiched my boat together, I used this method also. I placed my
> stiches about 2" apart, aligned the boat and filled between the stiches
> with thickened epoxy, when set I cut the stiches out and removed. At
> this point the boat is held together by the epoxy so don't try moving
> anything, then fill in the gaps left by the stiches with thickened
> epoxy. After this, finish the seams normally.
>
> This way I have no stiches buried in the epoxy. It is slower but
> easier. Just remember to remove the excess epoxy that may be squeezed
> out on the inside as you do this, or suffer the sanding job later.
>
without the wires getting in the way.
>If both boat building and the hatred of butt-straps have the same rootYikes - keep them dry...
>cause, can I expect to one day find the butt-strap in my teal not only
>displeasing on aestetic grounds, but morally deficient?
>
>BTW: I glued (carpenters' glue) mine
> and put a cinder block on 'em over
>night. No nails, no wax paper, no problem (so far.)
Fellow Bolger Boat Builders --
Why the hatred of butt-straps? Is there some reason to put all this
effort into making a seamless joint, or does can I attribute this to
the same urge that causes us to build our own boats when there are
plenty of very nice, professionally contructed boats begging for owners.
And.
If both boat building and the hatred of butt-straps have the same root
cause, can I expect to one day find the butt-strap in my teal not only
displeasing on aestetic grounds, but morally deficient?
BTW: I glued (carpenters' glue) mine and put a cinder block on 'em over
night. No nails, no wax paper, no problem (so far.)
--David
Why the hatred of butt-straps? Is there some reason to put all this
effort into making a seamless joint, or does can I attribute this to
the same urge that causes us to build our own boats when there are
plenty of very nice, professionally contructed boats begging for owners.
And.
If both boat building and the hatred of butt-straps have the same root
cause, can I expect to one day find the butt-strap in my teal not only
displeasing on aestetic grounds, but morally deficient?
BTW: I glued (carpenters' glue) mine and put a cinder block on 'em over
night. No nails, no wax paper, no problem (so far.)
--David
Hello Guys
There is another alternative to fair fibre-glass "butt-straps". This is to treat them like the joint in panels of what we call Jib-board. I think you yanks call it "dry-wall". It involves basic smoothing ot the butt-strap during the initial glue up - dispensing with wax paper etc. You then use fairing compound to smooth the joint, make a 6" wide layer each side of butt line first coat, second coat is 12" wide, third is 18" wide. You need a really big trowel to do the last couple of coats.
John Welsford, a NZ small boat designer taught me this trick and it results
in the fairest of joints of any method.
Regards - Foster Price
----------
From:monica@...
Sent: Wednesday, 6 October 1999 12:21 pm
To:bolger@egroups.com
Subject: [bolger] Re: Square Scarfs
So square is finally in?
The plywood scarfs I've made were all in 1/4" stock... a 12:1 scarf is
just 3 inches long as I cut it with a belt sander and the coarses belt
I could find.
(Definately asking Santa for a power planer this year.)
If I were attempting a stepped scarf I'd keep the same 12:1 ratio,
meaning I'd make the scarf 6" long. And I'd count my plys and make a
step to each one (give or take), or make at least 4 equal steps to
distribute the strain over a wider area.
In any case, with my current boat (a Catfish) I plan a simple
"fiberglass buttstrap" under the final fiberglass sheething.
------------------------------------------------------------------------
eGroups.com home:http://www.egroups.com/group/bolger
http://www.egroups.com- Simplifying group communications
There is another alternative to fair fibre-glass "butt-straps". This is to treat them like the joint in panels of what we call Jib-board. I think you yanks call it "dry-wall". It involves basic smoothing ot the butt-strap during the initial glue up - dispensing with wax paper etc. You then use fairing compound to smooth the joint, make a 6" wide layer each side of butt line first coat, second coat is 12" wide, third is 18" wide. You need a really big trowel to do the last couple of coats.
John Welsford, a NZ small boat designer taught me this trick and it results
in the fairest of joints of any method.
Regards - Foster Price
----------
From:monica@...
Sent: Wednesday, 6 October 1999 12:21 pm
To:bolger@egroups.com
Subject: [bolger] Re: Square Scarfs
So square is finally in?
The plywood scarfs I've made were all in 1/4" stock... a 12:1 scarf is
just 3 inches long as I cut it with a belt sander and the coarses belt
I could find.
(Definately asking Santa for a power planer this year.)
If I were attempting a stepped scarf I'd keep the same 12:1 ratio,
meaning I'd make the scarf 6" long. And I'd count my plys and make a
step to each one (give or take), or make at least 4 equal steps to
distribute the strain over a wider area.
In any case, with my current boat (a Catfish) I plan a simple
"fiberglass buttstrap" under the final fiberglass sheething.
------------------------------------------------------------------------
eGroups.com home:http://www.egroups.com/group/bolger
http://www.egroups.com- Simplifying group communications
So square is finally in?
The plywood scarfs I've made were all in 1/4" stock... a 12:1 scarf is
just 3 inches long as I cut it with a belt sander and the coarses belt
I could find.
(Definately asking Santa for a power planer this year.)
If I were attempting a stepped scarf I'd keep the same 12:1 ratio,
meaning I'd make the scarf 6" long. And I'd count my plys and make a
step to each one (give or take), or make at least 4 equal steps to
distribute the strain over a wider area.
In any case, with my current boat (a Catfish) I plan a simple
"fiberglass buttstrap" under the final fiberglass sheething.
The plywood scarfs I've made were all in 1/4" stock... a 12:1 scarf is
just 3 inches long as I cut it with a belt sander and the coarses belt
I could find.
(Definately asking Santa for a power planer this year.)
If I were attempting a stepped scarf I'd keep the same 12:1 ratio,
meaning I'd make the scarf 6" long. And I'd count my plys and make a
step to each one (give or take), or make at least 4 equal steps to
distribute the strain over a wider area.
In any case, with my current boat (a Catfish) I plan a simple
"fiberglass buttstrap" under the final fiberglass sheething.
To Gregg:
Did you use any type of formula to determine how far back to make the lap?
A 3/4 in. bottom on a Sneakeasy? Do the fish in Oklahoma lakes have
shotguns? Don't you think you should write an article for WoodenBoat about
"Square Scarfs"? Really, if this works, you'd almost be better off having
two of the lap joints in one of bolger's 16' boats and avoid the ugliness of
a buttstrap all together.
Thanks Gregg
To Michael:
So you ended up using the "fiberglass buttstrap" I've seen described in your
sides? That looks like it would finish off nice and clean.
One thing I keep staring at the plans and the key (and Payson's book)
without figuring out. The miships mold (temporary) is to be positioned on
the line scibed on the sides during building. Does this mean directly
centered? should the mold be aft of the line of forward of it?
thanks for your help Michael.
Robert Lundy
St. Petersburg, Fla.
Did you use any type of formula to determine how far back to make the lap?
A 3/4 in. bottom on a Sneakeasy? Do the fish in Oklahoma lakes have
shotguns? Don't you think you should write an article for WoodenBoat about
"Square Scarfs"? Really, if this works, you'd almost be better off having
two of the lap joints in one of bolger's 16' boats and avoid the ugliness of
a buttstrap all together.
Thanks Gregg
To Michael:
So you ended up using the "fiberglass buttstrap" I've seen described in your
sides? That looks like it would finish off nice and clean.
One thing I keep staring at the plans and the key (and Payson's book)
without figuring out. The miships mold (temporary) is to be positioned on
the line scibed on the sides during building. Does this mean directly
centered? should the mold be aft of the line of forward of it?
thanks for your help Michael.
Robert Lundy
St. Petersburg, Fla.
> -----Original Message-----
> From: GHC [mailto:ghartc@...]
> Sent: 05 October, 1999 6:13 PM
> To:bolger@egroups.com
> Subject: [bolger] Re: Square Scarfs
>
>
> That's just what I did on the 3/4" bottom of my sneakeasy, with no
> complaint...
>
> Gregg Carlson
>
> At 03:26 PM 10/4/1999 -0400, you wrote:
> > "" bottom in the plan (but I would have to cough up for an extra
> >sheet of plywood), I've been trying to think of a better way to
> make my two
> >8' sheets one long sheetwithout using a buttstrap plywood
> scarfed in
> >this manner. Comments from any more experienced woodworkers are most
> >appreciated. Ha, Ha. & Amy Lundy
> >St. Petersburg, Fla.
> > Click Here! eGroups.com home:
>http://www.egroups.com/group/bolger
> > www.egroups.com - Simplifying group communications
> >
>
>
> ------------------------------------------------------------------------
>
> eGroups.com home:http://www.egroups.com/group/bolger
>http://www.egroups.com- Simplifying group communications
>
>
>
>
That's just what I did on the 3/4" bottom of my sneakeasy, with no
complaint...
Gregg Carlson
At 03:26 PM 10/4/1999 -0400, you wrote:
complaint...
Gregg Carlson
At 03:26 PM 10/4/1999 -0400, you wrote:
> "" bottom in the plan (but I would have to cough up for an extra
>sheet of plywood), I've been trying to think of a better way to make my two
>8' sheets one long sheetwithout using a buttstrap plywood scarfed in
>this manner. Comments from any more experienced woodworkers are most
>appreciated. Ha, Ha. & Amy Lundy
>St. Petersburg, Fla.
> Click Here! eGroups.com home:http://www.egroups.com/group/bolger
> www.egroups.com - Simplifying group communications
>
I've been contemplating the easiest method of attachment for my 1/2 in. Windsprint bottom. Since deciding to do this meant I didn't have to follow the "three piece" bottom in the plan (but I would have to cough up for an extra sheet of plywood), I've been trying to think of a better way to make my two 8' sheets one long sheetwithout using a buttstrap
I've had great luck lapping joints previously in smaller projects. Basically, you use your dado blade or router to remove an area 4 in back from the edge of each sheet, 1/2 the thickness of the sheet. Slather with glue, lap the joint and stack concrete blocks on top for pressure. Seems pretty straightforward. Except that I've never seen and article about plywood scarfed in this manner.
I'll try to make up some test pieces and break them to see where they shatter. Comments from any more experienced woodworkers are most appreciated.
Oh, and I really appreciated the comments about my wax paper fiasco. I'll have to ask Mr. Payson to make his techniques geographically neutral. Ha, Ha.
Robert & Amy Lundy
St. Petersburg, Fla.