SANDY, Styrofoam 3 Panel

[RealBigReel]

Bought 3 sheets of 3/4" blue styrofoam from Lowes 2/24/11.

02/28/11, Today I started cutting parts out.



Cuts like butter with a utility knife. This styrofoam can be cut using a straight edge like sheetrock. Makes a fairly clean edge cut. Not a lot of those little pieces of debris you usually get with styrofoam like when you cut with a saw.
There is enough flex in the sides to accommodate the 1.625" rocker.



4 hours later, preliminary fit check. When I am ready to glass I will pull the plastic coatings off.
Ducks tape tears the plastic coatings off of the styrofoam when removed.

[gerald]

This will be a project I watch with great interest.

[Light Keeper's Kid]

Me Too

Mike

[neon14]

Yes, I will have to say that you have my total attention.

[Buckeev]

This will be a project I watch with great interest.

Color my interest piqued.

[awoodman]

A composite build.
On another forum back in 06 a guy started a foam core hydro but it never got finished, he had all the braces and panels cut then the post just died.

This will be interesting. Have you done a test panel to test the strength?

[makenmend]

Inovative as usual, will also be following this build.

MM

[G-Man]

Intrigued myself...

Might be thinking of a paddleboard build using styrofoam??? Anyone?

G-Man

[awoodman]

Intrigued myself...

Might be thinking of a paddleboard build using styrofoam??? Anyone?

G-Man

That would be my choice at least the inside supports and deck...

[RealBigReel]

A composite build.
On another forum back in 06 a guy started a foam core hydro but it never got finished, he had all the braces and panels cut then the post just died.

This will be interesting. Have you done a test panel to test the strength?

BTW that is a nice looking boat there in your avatar.

Most all of these boats are "composite". Epoxy/Glass over wood. Styrofoam core is hardly new. Most surfboards are made of it.
Glassed up my first parts this morning.



The bulkheads.
Plan on a little trip to Lake Proctor and then glass the other side this afternoon/evening, depending on how the fishing goes.

As far as weight is concerned. Most all of these boats are made of wood core and Epoxy/Glass inside and out. That means it will take at least the better part of a gallon kit of epoxy, which is 11 lbs per gallon. So the epoxy weighs about 15 lbs.
With hand layup you don't save any weight going with exotic fabrics. Kevlar slurps up epoxy and so does Graphite. So unless you can do vacuform, exotics may give you a little extra strength but they will cost you weight with a hand layup.
My boat design takes about about 10 yards of fabric to cover and so 6 ounce glass cloth weighs 3.75 lbs.
So I am up to about 19 lbs right there.

My 3 panel design has about 5900 square inches of core, so:
If I built it out of .2 thk Luan underlayment (34 lbs per cubic foot or 18 lbs/sheet) the core structure would weigh 23.21 lbs and the basic hull would weigh 42 lbs.
If I built it out of .125 thk WRC (24 lbs/cubic foot) the core structure would weigh 10.24 lbs, and the basic hull would weigh about 29 lbs.
If I built it out of .25 thk 8 lb density Balsa (like HYBRID) the core would weigh 6.83 lbs and the basic hull would weigh about 26 lbs.
If I built it out of .75 thk 2 lb density Styrofoam the core would weigh 5.12 lbs and the basic hull would weigh 24 lbs. However probably need to add in a couple of pounds for hard points like nose, tail and gunnels.

Observations.
Luan is the least expensive and the most prone to failure.
WRC is the next least expensive (depending on source), the most labor and equipment intensive and by far the most beautiful.
Balsa is the most expensive (comparable to marine plywood), is easy to work with and has a low basic strength.
Styrofoam sheet is potentially the lightest, the weakest, the least attractive, is easy to work except for the little pieces of static charged debris. Cuts cleanly as long as the knife is sharp and a guiding edge is used. Sanding styrofoam requires respiratory protection.

[awoodman]

It would be interesting to do stress (break) test panels out of a variety of materials.

You talk like you have done this type construction before.

Surfboards take a beating but not quite like bumping rocks and tree stobs just under the water surface etc. in a river. I'd be hesitant of using foam for the bottom panel.

And where I live the lumber supp. (and I have tried them all) say in would cost (an-arm-and-a-leg) in shipping to get marine ply. delivered. This is why I am forced to use cedar or luan...

[neon14]

I accidentally bought 2 sheets of Styrofoam at home depot today.

[RealBigReel]

I accidentally bought 2 sheets of Styrofoam at home depot today.

Accidentally?

3/2/11 Glassed the other side of the bulkheads and the joint in the 2 bottom panels.
Test:



That is 40 lbs sitting there.
Epoxy adhesion to Styrofoam is good. Does not soak in like with wood. Seems to be more of a chemical bond.

3/3/11
Epoxied the bulkheads in place last night, glass fillet on one side.



They are reasonably rigid this morning.

[awoodman]

Wow 40 lbs. that is cool. And that is just one coat of epoxy on each side right, with the weave not fully filled in?

With this type of core weight reduction a guy could add a second layer of cloth to the bottom panel to make it even more bullet proof.

[RealBigReel]

Wow 40 lbs. that is cool. And that is just one coat of epoxy on each side right, with the weave not fully filled in?

With this type of core weight reduction a guy could add a second layer of cloth to the bottom panel to make it even more bullet proof.

Yes just one coat of epoxy over 3 oz glass each side.

Sounds good to me, we'll see.

[wilded]

My cedar boat flexes when I get in and out. I would think with flex the foam core would crack. Just asking. ET

[neon14]

wilded, I don't think it would crack. If anything it would dent. I have been doing a little experimenting the last couple days with this stuff and it looks pretty promising.

[awoodman]

I can't help imagining a submerged tree stob poking through a foam bottom panel.
I wonder what kind of comparison test could simulate a blow to a panel like that?

[bowgarguide]

RBR
Are you going to have any perforations through the foam.
and did you rough it up in areas of high impact.
Both those things will greatly enhance the ability to take a lick and keep on ticking.
Ron

[RealBigReel]

I can't help imagining a submerged tree stob poking through a foam bottom panel.
I wonder what kind of comparison test could simulate a blow to a panel like that?

Hit anything hard enough and something will give, but I don't see a tree stump harming SANDY. For one thing this design drafts less than 3.5 inches. The bottom is virtually flat with 1.625" rocker. It will have at least 1 heavy (6 oz or so) layer of glass, and Epoxy/graphite coating.

I hit a trip stump yesterday in HYBRID. Just slid off. Hardly even notice it. Sandy has the same planform as HYBRID.

[RealBigReel]

RBR
Are you going to have any perforations through the foam.
and did you rough it up in areas of high impact.
Both those things will greatly enhance the ability to take a lick and keep on ticking.
Ron

No perforations
No roughing, can't see any benefit there, because the epoxy to styrofoam bond is better than the material.
The premise of this design is keep it simple, cheap and light. I want avoid any unnecessary complication, cost and weight.
I will reinforce the nose, tail and gunnels with wood, and that will make it easy to attach hardware.
It will have rod holders and a cooler slot but not much else in the way of accoutrement.

[neon14]

Technically you could have a built in cooler

[Lusca]

How about a built in bait/livewell? Say 6 to 8 gallon capacity. Round or oval shape. Some kind of free flowing water exchange along the lines of a venturi, or just several small holes like a glorified minnow bucket . That way, no batteries or mechanical pumps. When not in use a plug to keep the water out. I'd love to incorporate something like that for my shad. I'd want it below the deck, just under my legs. That space would work with your SOT design I believe.

[RealBigReel]

Technically you could have a built in cooler

Thought of that. I like to have the cooler portable. That way I have the area behind it for storage in the kayak. I can take the cooler in the house to clean the fish, and it easier to wash out afterwards.

[RealBigReel]

How about a built in bait/livewell? Say 6 to 8 gallon capacity. Round or oval shape. Some kind of free flowing water exchange along the lines of a venturi, or just several small holes like a glorified minnow bucket . That way, no batteries or mechanical pumps. When not in use a plug to keep the water out. I'd love to incorporate something like that for my shad. I'd want it below the deck, just under my legs. That space would work with your SOT design I believe.

Staying with simple on this build. I have a 5 gallon bait tank in HYBRID, although it is not passive, it does have an electric pump.
Good idea though. Could be done. It would only be 3 inches deep though.

3/7/11
Did a little fill work around the inside edges and then glassed over it before it cured.



Can't hardly see the glass but it is there. Front 2/3 rds of the inside done. Back 1/3 rd will require more fill before it is glassed.

Went out and bought some 1" corner molding (3/4" inside) for the tumblehome edges.

3/7/11 Afternoon. Got the the aft portion filled and glassed.

3/8/11
Trimmed the bottom deck. Prepared for tumblehome install.



Tumblehome tacked in place. Some work on nose and tail too.

3/9/11 Tumblehome filled and glassed inside.
Gunnel rail bonded in place.
It is 65° in the garage but 39° outside. May take this a while to cure up.

By afternoon it was pretty solid so I cut the extra off of the tumble home. Trimmed up around the edges and did some sanding.



Starting to look like a kayak. The shape is now rigid enough that it won't twist or bend when I pick it up and move it around.
Out of Glass cloth and low on epoxy. On order.
Order hardware from ACK yesterday and got it today.

3/10/11 This morning I attached the nose under-piece. This will support the piece of wood that the screws go into for the handle and the padeye.
Attached the first section of rear decking. This is the piece that goes behind the seat and in front of the cooler.
Laid on a little or glass from some scraps and tape that I had left. Closed up some patches of uncovered skin.

3/14/11 Mixed the last of the epoxy. Laid on a couple of patches of glass on the inside.
Epoxied the hatch cover on HYBRID.
Epoxied up a replacement for HYBRIDS camlock.
Glassed the area right behind the seat, in front of the cooler.
Received the Surf to Summit seat today. Fishing seat pack may not work with SANDY but the seat looks really comfortable.
Epoxied the top nose piece. This is a piece of pine that will accept the screws for the the handle and the padeye.
Did some work on the tale area.

3/16/11 Went fishing yesterday, and got my order from US Composites yesterday. Got up late for me today.
Got the rear deck glassed on the underside and installed.
Got the patches in the seat area done.
Got the foot area glassed over with 6 oz (over 3 oz). Hoping that will be tough enough.
Got the front area glassed up the sidewalls.
Bunch of fillets glassed.
Evening, added left front deck tumble home.