I thought paper mache was done with starch
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nothing wrong with thinking outside of the box.
but a bit of homework to put all these 'unique' materials in perspective may help you quantify how much of each you may need.
the fact that you still plan to use a foam core suggests that there will be something to wash up on the beach no matter what the skin is composed of.
many boats and docks have been built out of foam with no additional reinforcement.
maintaining as much core thickness as possible will increase flexural strengh dramatically.
using a 1/2 pine stringer may make the need for a paper skin moot
(paper and pine were the same thing at one point)
bear in mind glass/epoxy has a tensile strength on the order of 30,000-60,000 psi
and an elastic modulus in the neighborhood of 8,000,000 psi
that said:
if you are using a paper/pulp/varnish-something that has a tensile strength of 5000-10,000 psi.
how much stuff (at what weight ) will you need to replace the function of glass?
will this be a better design choice than simply using a thicker blank with no skin?
some small materials testing to quantify tensile strength or flexural strengh of your favorite choices will go a long way.
matweb.com has lots of material properties to browse thru and see what may be possible
(ie http://www.matweb.com/search/DataSheet.aspx?MatGUID=17fed06ca7284a2187d7ec8790061164)
if your willing to conceed the need for varnish why bother with flour and water as a binder?
g-10 was not invented for surfboards, it was simply part of the natural progression in developing electrical insulation materials.
look up some of the earier versions, g-4 or garolite which i believe were phenolic resin using paper or cotton fiber for reinforcement.
by all means, make your comparisons to Edison, if you wish.
But he did know what he was doing.
regards,
bill
Thanks for all these suggestions.A lot of food for thought. A lot more possibilities than I first anticipated. A lot more homework to do. I have been groping intuitively through the dark up until now.
Board in box!
I saw someone had posted a pic of these boards but I just have to share this link to the vid, it's awesome.
http://www.korduroy.tv/2010/inner-views-mike-sheldrake
These boards might work out real well or not?
The interresting thing about this though is the build process and the concept of shipping it. This is something that I think will evolve. And on top of that they look really cool. Imagine..
Hey I know this is an old thread but thought I would ask how the project went or is coming along and add a few comments.
Building a composite board using celulose fiber is really not much different then using fiberglass or kevlar or any other fiber, a wooden board is made of the same fiber just oriented and bonded naturally. Most paper has randomly oriented fibers which are reasonably short… The length of the fibers in a sample can be estimated by tearing it and seeing the average size of the jagged edges. Paper or cardboard has been used for a fair number of high strength products including aircraft drop tanks in WWII and various artilary projectiles.
The key to any sandwich board construction is the upper and lower surfaces which bear the load in compression or tension and a medium in the middle that prevents the distance between them from changing so they can do their job without buckling. Alot of boards do this with foam to hold the surfaces in place that you then cover in fiberglass of kevlar or whatever you like. Honeycomb materials can also be used for sandwich construction and you will readily find cardboard honeycombs you could work with. The honey comb may work better for supporting the surface and preventing dents from forming. If you are already using celulose elsewere then why not use cardboard honeycomb as a neutral axis. You can also make honeycomb by folding paper (forward forward back back forward forward back back etc) and bonding parralell strips to each other with whatever glue you are using.
The matrix is the part of a composite that holds it together and in the case of paper thats usually a natural starch or sugar or an introduced one. In paper mache you add more starch usually and when you varnish it you are also adding a polymer (usualy polyester or polyurithane) Starches are water soluable but if used where water doesnt go like the interior of the board it should not be a problem however to stand up to a puncture and be repairable you might want to use the varnish or other epoxy or polymer glue there too.
Another method of construction would be to make ribs and stringers out of layered paper so that a boat like structure was created and then place the surface layers over that. if layed thickly enough now denting would happen or the upper surface could have a thinner honeycomb layer on top to distribute the load with a secondary surface. the cardboard and paper covered in varnish should be very sandable when dry and there is no reason a high gloss finish cannot be obtained.
Id say good luck to anyone trying this I am sure it can be done and done well.