Re: [bolger] foam boat - was Skimmer
Actually, the "grossest" failure was separation of the joint between foam
boards in the sides just forward of the middle seat box structure, from
wracking of the forward part of the boat while planing at 12 mph in a chop.
This use was clearly beyond the capability of this structure, so I count
that my fault. The fragility of the bottom laminate just wasn't something
I wanted to work around. The new owner (I repaired the damage) keeps it
drawn up on the grass beside a 22 acre residential lake with no motors
allowed. It should last a long time in that environment.
Don Hodges
boards in the sides just forward of the middle seat box structure, from
wracking of the forward part of the boat while planing at 12 mph in a chop.
This use was clearly beyond the capability of this structure, so I count
that my fault. The fragility of the bottom laminate just wasn't something
I wanted to work around. The new owner (I repaired the damage) keeps it
drawn up on the grass beside a 22 acre residential lake with no motors
allowed. It should last a long time in that environment.
Don Hodges
----- Original Message -----
From: GHC <ghartc@...>
To: <bolger@egroups.com>
Sent: Sunday, June 04, 2000 8:12 PM
Subject: Re: [bolger] foam boat - was Skimmer
> In bending this sandwich, the outside skins carry tension and compression.
> However, the centerline - the foam - carries the maximum shear stress.
> Since styrofoam has no strength, the skins will separate or the foam will
> split down the middle, way before the skins take much load. Of course,
> loading up on the skins won't make it any stronger.
>
> So, you can't get something for nothing - you have to use some reasonably
> strong core material.
>
> Gregg Carlson
>
>
> At 09:37 PM 7/13/00 -0800, you wrote:
> >Did you fiberglas the styrofoam inside and out?. It makes a big
> >difference on how it acts if one or both sides are fiberglassed.
> >I have done a little bit of foam core work and it has done well.
> >Plywood construction is much, much faster.
> >
> >HJ
> >
> >
> >Donald Hodges wrote:
> >>
> >> I built one of these (not Skimmer, but a Styrofoam/glass jonboat about
11
> >> feet x 44 inch beam). Mine was almost all styrofoam, seats were 1/8
> >> doorskin laminated to 3/4 styrofoam, about 60 lb. It was too flimsy
to
> >> slide in and out of my pickup, and the last straw was putting on a 6hp
> >> outboard, which quickly started it breaking up. I replaced it with
the 12
> >> foot luan skiff and gave the foam boat to a friend who lives on a small
"no
> >> powerboat" lake. I found that using a trolling motor negated all the
> weight
> >> savings, and it could be rowed effortlessly faster than the trolling
motor
> >> would push it (SMALL troller).
> >>
> >> I would strongly recommend avoiding this particular laminate - the
> Styrofoam
> >> just has zero structural properties. If you can't resist, be sure to
peel
> >> the polyethylene "scrim" off before laying up the fiberglass; this
gives
> the
> >> best (not great) bond.
> >>
> >> A minimum-freeboard ply pram or skiff will only be 10-15 lb heavier and
> MUCH
> >> more rugged.
> >>
> >> Don Hodges
> >>
> >>
> >_ _ _ _ _
> >% Harrywelshman@...
> >
> >------------------------------------------------------------------------
> >Get a NextCard Visa, in 30 seconds!
> >1. Fill in the brief application
> >2. Receive approval decision within 30 seconds
> >3. Get rates as low as 2.9% Intro or 9.9% Fixed APR
> >http://click.egroups.com/1/6631/13/_/3457/_/963552533/
> >------------------------------------------------------------------------
> >
> >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.
> >
> >
>
>
> ------------------------------------------------------------------------
> Life's too short to send boring email. Let SuperSig come to the rescue.
>http://click.egroups.com/1/6809/13/_/3457/_/963583297/
> ------------------------------------------------------------------------
>
> 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.
>
>
Yep, in and out with fillets, built up the middle seat into a live box with
'glassed foam boards, the forward and aft seats had fiberglassed paper tubes
tabbed in under the foam/doorskin laminated seats. It had doorskin
floorboards to prevent overstressing by stepping in/out. It was just a bit
too big (eyeball-built), which resulted in too much weight even on just one
end when dragging in/out of truck. When it reached the critical point of
tipping to the ground, the stress along the line across the bottom was
enough to compress the foam and precipitate delamination. I built a rack to
slide it in and out on, but the real end was trying to power it. I
deliberately built the little ply skiff without a transom suitable for
power. I think the composite would be adequate in an 8-footer for rowing
and perhaps sailing only, but I can't justify the cost and complexity
against the plywood alternative. As I recall, I had about $300 in materials
and paint in this 11 footer.
Don Hodges
'glassed foam boards, the forward and aft seats had fiberglassed paper tubes
tabbed in under the foam/doorskin laminated seats. It had doorskin
floorboards to prevent overstressing by stepping in/out. It was just a bit
too big (eyeball-built), which resulted in too much weight even on just one
end when dragging in/out of truck. When it reached the critical point of
tipping to the ground, the stress along the line across the bottom was
enough to compress the foam and precipitate delamination. I built a rack to
slide it in and out on, but the real end was trying to power it. I
deliberately built the little ply skiff without a transom suitable for
power. I think the composite would be adequate in an 8-footer for rowing
and perhaps sailing only, but I can't justify the cost and complexity
against the plywood alternative. As I recall, I had about $300 in materials
and paint in this 11 footer.
Don Hodges
> Did you fiberglas the styrofoam inside and out?. It makes a big11
> difference on how it acts if one or both sides are fiberglassed.
> I have done a little bit of foam core work and it has done well.
> Plywood construction is much, much faster.
>
> HJ
>
>
> Donald Hodges wrote:
> >
> > I built one of these (not Skimmer, but a Styrofoam/glass jonboat about
> > feet x 44 inch beam). Mine was almost all styrofoam, seats were 1/812
> > doorskin laminated to 3/4 styrofoam, about 60 lb. It was too flimsy to
> > slide in and out of my pickup, and the last straw was putting on a 6hp
> > outboard, which quickly started it breaking up. I replaced it with the
> > foot luan skiff and gave the foam boat to a friend who lives on a small"no
> > powerboat" lake. I found that using a trolling motor negated all theweight
> > savings, and it could be rowed effortlessly faster than the trollingmotor
> > would push it (SMALL troller).Styrofoam
> >
> > I would strongly recommend avoiding this particular laminate - the
> > just has zero structural properties. If you can't resist, be sure topeel
> > the polyethylene "scrim" off before laying up the fiberglass; this givesthe
> > best (not great) bond.MUCH
> >
> > A minimum-freeboard ply pram or skiff will only be 10-15 lb heavier and
> > more rugged.
> >
> > Don Hodges
> >
> >
> _ _ _ _ _
> % Harrywelshman@...
>
> ------------------------------------------------------------------------
> Get a NextCard Visa, in 30 seconds!
> 1. Fill in the brief application
> 2. Receive approval decision within 30 seconds
> 3. Get rates as low as 2.9% Intro or 9.9% Fixed APR
>http://click.egroups.com/1/6631/13/_/3457/_/963552533/
> ------------------------------------------------------------------------
>
> 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.
>
>
Did you fiberglas the styrofoam inside and out?. It makes a big
difference on how it acts if one or both sides are fiberglassed.
I have done a little bit of foam core work and it has done well.
Plywood construction is much, much faster.
HJ
Donald Hodges wrote:
% Harrywelshman@...
difference on how it acts if one or both sides are fiberglassed.
I have done a little bit of foam core work and it has done well.
Plywood construction is much, much faster.
HJ
Donald Hodges wrote:
>_ _ _ _ _
> I built one of these (not Skimmer, but a Styrofoam/glass jonboat about 11
> feet x 44 inch beam). Mine was almost all styrofoam, seats were 1/8
> doorskin laminated to 3/4 styrofoam, about 60 lb. It was too flimsy to
> slide in and out of my pickup, and the last straw was putting on a 6hp
> outboard, which quickly started it breaking up. I replaced it with the 12
> foot luan skiff and gave the foam boat to a friend who lives on a small "no
> powerboat" lake. I found that using a trolling motor negated all the weight
> savings, and it could be rowed effortlessly faster than the trolling motor
> would push it (SMALL troller).
>
> I would strongly recommend avoiding this particular laminate - the Styrofoam
> just has zero structural properties. If you can't resist, be sure to peel
> the polyethylene "scrim" off before laying up the fiberglass; this gives the
> best (not great) bond.
>
> A minimum-freeboard ply pram or skiff will only be 10-15 lb heavier and MUCH
> more rugged.
>
> Don Hodges
>
>
% Harrywelshman@...
I built one of these (not Skimmer, but a Styrofoam/glass jonboat about 11
feet x 44 inch beam). Mine was almost all styrofoam, seats were 1/8
doorskin laminated to 3/4 styrofoam, about 60 lb. It was too flimsy to
slide in and out of my pickup, and the last straw was putting on a 6hp
outboard, which quickly started it breaking up. I replaced it with the 12
foot luan skiff and gave the foam boat to a friend who lives on a small "no
powerboat" lake. I found that using a trolling motor negated all the weight
savings, and it could be rowed effortlessly faster than the trolling motor
would push it (SMALL troller).
I would strongly recommend avoiding this particular laminate - the Styrofoam
just has zero structural properties. If you can't resist, be sure to peel
the polyethylene "scrim" off before laying up the fiberglass; this gives the
best (not great) bond.
A minimum-freeboard ply pram or skiff will only be 10-15 lb heavier and MUCH
more rugged.
Don Hodges
feet x 44 inch beam). Mine was almost all styrofoam, seats were 1/8
doorskin laminated to 3/4 styrofoam, about 60 lb. It was too flimsy to
slide in and out of my pickup, and the last straw was putting on a 6hp
outboard, which quickly started it breaking up. I replaced it with the 12
foot luan skiff and gave the foam boat to a friend who lives on a small "no
powerboat" lake. I found that using a trolling motor negated all the weight
savings, and it could be rowed effortlessly faster than the trolling motor
would push it (SMALL troller).
I would strongly recommend avoiding this particular laminate - the Styrofoam
just has zero structural properties. If you can't resist, be sure to peel
the polyethylene "scrim" off before laying up the fiberglass; this gives the
best (not great) bond.
A minimum-freeboard ply pram or skiff will only be 10-15 lb heavier and MUCH
more rugged.
Don Hodges
----- Original Message -----
From: Michael Surface <msurface@...>
To: <bolger@egroups.com>
Sent: Tuesday, July 11, 2000 8:38 AM
Subject: Re: [bolger] Skimmer
> Don't know if this will be of any help but here is a URL for a Skimmer
> build out of Styrofoam covered in fiberglass. I makes for a very lite
> weight and buoyant boat.
>
>http://hometown.aol.com/polysail/HTML/boatnote.htm
>
> Michael Surface
>
>
> >From:col_mooney@...
> >Reply-To:bolger@egroups.com
> >To:bolger@egroups.com
> >Subject: [bolger] Skimmer
> >Date: Tue, 11 Jul 2000 08:15:59 -0000
> >
> >
> >
> >Have put Martha Jane on hold for a few weeks, the daughters boyfriend
> >wants an el-cheapo fishing boat. Has anyone out there built 8 foot
> >Skimmer before? Any tips, useful modifications etc? Is quarter inch
> >ply sufficient?
> >
> >Col M
> >
>
> ________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail athttp://www.hotmail.com
>
>
> ------------------------------------------------------------------------
> Free Conference Calling with Firetalk!
> Click Here!
>http://click.egroups.com/1/5480/13/_/3457/_/963322699/
> ------------------------------------------------------------------------
>
> 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.
>
>
In bending this sandwich, the outside skins carry tension and compression.
However, the centerline - the foam - carries the maximum shear stress.
Since styrofoam has no strength, the skins will separate or the foam will
split down the middle, way before the skins take much load. Of course,
loading up on the skins won't make it any stronger.
So, you can't get something for nothing - you have to use some reasonably
strong core material.
Gregg Carlson
At 09:37 PM 7/13/00 -0800, you wrote:
However, the centerline - the foam - carries the maximum shear stress.
Since styrofoam has no strength, the skins will separate or the foam will
split down the middle, way before the skins take much load. Of course,
loading up on the skins won't make it any stronger.
So, you can't get something for nothing - you have to use some reasonably
strong core material.
Gregg Carlson
At 09:37 PM 7/13/00 -0800, you wrote:
>Did you fiberglas the styrofoam inside and out?. It makes a bigweight
>difference on how it acts if one or both sides are fiberglassed.
>I have done a little bit of foam core work and it has done well.
>Plywood construction is much, much faster.
>
>HJ
>
>
>Donald Hodges wrote:
>>
>> I built one of these (not Skimmer, but a Styrofoam/glass jonboat about 11
>> feet x 44 inch beam). Mine was almost all styrofoam, seats were 1/8
>> doorskin laminated to 3/4 styrofoam, about 60 lb. It was too flimsy to
>> slide in and out of my pickup, and the last straw was putting on a 6hp
>> outboard, which quickly started it breaking up. I replaced it with the 12
>> foot luan skiff and gave the foam boat to a friend who lives on a small "no
>> powerboat" lake. I found that using a trolling motor negated all the
>> savings, and it could be rowed effortlessly faster than the trolling motorStyrofoam
>> would push it (SMALL troller).
>>
>> I would strongly recommend avoiding this particular laminate - the
>> just has zero structural properties. If you can't resist, be sure to peelthe
>> the polyethylene "scrim" off before laying up the fiberglass; this gives
>> best (not great) bond.MUCH
>>
>> A minimum-freeboard ply pram or skiff will only be 10-15 lb heavier and
>> more rugged.
>>
>> Don Hodges
>>
>>
>_ _ _ _ _
>% Harrywelshman@...
>
>------------------------------------------------------------------------
>Get a NextCard Visa, in 30 seconds!
>1. Fill in the brief application
>2. Receive approval decision within 30 seconds
>3. Get rates as low as 2.9% Intro or 9.9% Fixed APR
>http://click.egroups.com/1/6631/13/_/3457/_/963552533/
>------------------------------------------------------------------------
>
>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.
>
>