Paper raft

[psi20]

I'm building a paper raft using 1 sheet of notebook paper and glue. I'm going to put one penny at a time onto the raft to see how much pennies it will carry before water leaks in.

 

What's the most amount of pennies you've heard of being put onto a paper raft?

[SubJunk]

are you serious? why?

[psi20]

Just for fun. Or was that a rhetorical and philosophical question?

[Cap'n Refsmmat]

In an aluminum foil raft made out of 1 square foot of aluminum foil, 272.

That was my raft.

[Halash]

you must obtain the largest surface area with the least amount of weight to float the most.... that owuld be a sphere shape... or in this case a hemisphere

[psi20]

Actually, I'm trying to not use that kind of raft. I did that as a control experiment to see how many pennies I could make it hold. Mine, very crudely made, held 103 pennies, so I'm estimating that a hemisphere could hold 125 pennies easily.

 

The raft I'm trying to make probably isn't going to work with paper. It is a triangle sides the length of a little more than your middle finger. The sides are going to have air pockets and then I'm going to glue them shut. The left over paper makes 2 layers of floor space underneath. The floor is made of parts. These parts are folded so they fold either upward or downward. Hopefully this connected to the triangle sides are not going to leak water in.

 

What inspired me is the escape from Alcatraz. The three escapees made a raft that held them out of raincoats! A show called Mythbusters showed that it was possible to go from Alcatraz to the Marin Headlands using the flow of the westward current, contrary to popular belief about the escapees heading to Angel Island.

[Auk]

I'm interested in trying and I will post you my results soon. Just want to make it clear i can only use a normal piece of paper and some school glue right?

[psi20]

Yeah, tell me what you get. The rafts I made that I tried to make like the Alcatraz raft held between 20 and 30; I forget what the number was now that I've given up. The material just wasn't strong enough and I think glue changes the viscosity of the water. The raft was unbalanced causing pennies to slide and the boat to tilt over.

 

However, I found that the air bubbles were held pretty well in their paper capsules. But the bubbles weren't enough to lift up more than 20 something pennies.

[Auk]

K thx for the quick answer. Ill try it tomorrow.

[sepultallica]

people actually do this? why? it has to be boredom.

[Auk]

25 pennies.

[YT2095]

doesn`t the paper get soggy and all the pennies drop through the bottom as you`re counting them in?

[Auk]

ya youve got to put the pennnies in fast lol

[YT2095]

I figured something that wouldn`t float naturaly like a cone, it needs weight to stabilise it, maybe giving you a head start?

 

realisticly, you`de need to make the greatest water displacement as possible (so less folds to maximise the paper area), calculate total volume of water this can displace in grams, and then see how many pennies that is (that`s the easy part!)

 

now you`ve just got to figure a way to get them all in there without making papier mache`

[Auk]

Ya I tried different models. They were all pretty pathetic. lol

[psi20]

lol, yeah don't go on cruise ships made of paper is what this shows us

[Jake712]

Sounds like my physics project. We have to build cardboard boats without waterproofing the cardboard. In addition, we can only use ducktape and glue and they must be able to hold one person in them in the water.

[Phi for All]

I'm going to try this with my daughter tomorrow. I know a really slick origami fold for the boat so I won't have to use any glue.

[Verusamore]

Can we cut the paper in half ?

 

I remember making paper aeroplanes as a kid , that was probaly the best part being a kid and for the parent , it was and fun , cheap and educational .

[psi20]

Yeah

[Phi for All]

Well, we're definitely having material problems here. My origami boat folds in half due to wetness after about 40 pennies if we do them one at a time. If I place 70 in the boat before I put it in the water, it holds up fine. When I start placing more in, the sides slowly fold in due to the slight extra weight of dropping them in.

 

I think if I put three cut plastic straws across the top to brace the sides (no glue needed), I think it would keep the sides from folding in and sinking the boat. Are the straws cheating?

[psi20]

I didn't use straws, but it'd be interesting to see what would happen.

[coquina]

I don't think notebook paper and pennies are good materials for your experiment. As someone pointed out, the paper becomes waterlogged and sinks. If you paint it with glue to waterproof it, the glue will saturate the paper and make it less bouyant.

 

The pennies concentrate the weight in one area too much - so you can't balance the load. As your ballast - how about using sheets of aluminum foil cut to the same shape but slightly smaller than the inside of the raft, so that when you add a sheet you distribute the weight evenly.

 

Instead of notebook paper, use corrugated cardboard. You can spray a clear varnish on it to waterproof it, and you can close the ends so water can't enter the corrugations.

[jsatan]

you must obtain the largest surface area with the least amount of weight to float the most.... that owuld be a sphere shape... or in this case a hemisphere

 

 

nah doesnt matter on the shap, what matters is how much water you displace.

 

 

Ps the best thing I made with paper was in my first year of uni and I was helping some friends out.

 

anyway. I got some of that wax coated paper, (normally blue on one side)

and taped it in the just the right places as to make a air tight seal which under pressure will not pull apart, eaasy to do just a double seam etc etc.

 

anyway I made it and it was made from about 2 A3 paper size. you could site on it etc. and just to test how strong it was I jumped on it, it was so strong.

 

it was a comp to see who could make the best lightest chair out of paper products, eg card etc.

 

well I made 2 one out of pizza boxes to to show the guy whats what, (as it wasnt my compo)

 

and this on, the way it worls is paper is very strong at being pulled apart, but as you know will fold easy if pushed together.

 

bult it on that system and it is very very strong.

 

give it a try. lol.

[Auk]

I tried filling in the pennies before putting it in the water. I used an origami type boat. Pennies: 54.