i get an allergic problem with epoxy, so i have to shape my boards without “normal epoxy/polyester layup”!
so my plan is to build a board like sunova, but without the intermal layer of fiberglass and without a layer of glass outside. just with a thin layer of lindseed resin on the outside to get it watertight
so my question at all.
which thickness of balsa should i use in combination with an 1 lbs eps core?
my guess is something arround 3-5 mm. maybe 5 on top and 3mm on the bottom. i coul add a thin layer of fiberglas (3 oz) to the lindseeresin, but the bioresin is far weaker than normal epoxyresin. so the force must be held by the veneer/core…
what are your thougts?? maybe somebody tried in the past.
"The weight of each board obviously depends on the boards size, the
boards generally are surprisingly light and are pretty much the same
weight as a regular polyurethane/polyester resin surfboard."
“You can
expect a typical 6’4” to weigh 3.5kg."
Let’s do a little math:
Tiger Glass Method = 3.5kg.
High Performance Shortboard = 2.27kg.
That is a 35.14% increase in weight.
If Performance is not a requirement then follow the Tiger Method.
The density
of dry balsa wood ranges from 2.5-21 lb/ft³, with a typical density of
about 10 lb/ft³. It is also a very popular material to use when making
wooden crankbaits for fishing, as it is low density but high in strength
also used to make very light, stiff structures in model bridge tests
and for the construction of light wooden airplanes, most famously the
World War II de Havilland Mosquito. It is also used in the floor pan of
the Chevrolet Corvette Z06 sandwiched between two sheets of carbon
fiber-reinforced polymer. In table tennis paddles, a balsa layer is
typically sandwiched between two pieces of thin plywood. Balsa wood is
also used in laminates with glass-reinforced plastic (fiberglass) for
making high-quality balsa surfboards and the decks and topsides of many
types of boats, especially pleasure craft under 30 m (100 ft) in length.
I would recommend 3mm poplar plywood, auf deutsch Pappelsperrholz. It’s density and durability is higher than balsa wood. Its much cheaper and available at many german baumärkten. But use bootslack (spar varnish) or similar varnish to seal it, not linseed oil. I built a few surfboards with 1#eps and poplar, but since now always glassed them lightly. But I’ll try without glassing soon.
check out www.glass-tiger.com, an boardmaker from cornwall uk that builds glass-less surfboards just made of wood and foam.
Instead of poplar plywood it’s also possible to use 1-1,5mm birch ply. It’s only available up to 1,5x1,5m sheets, so you have to connect to pieces for a surfboard. It’s stronger than poplar though, also more expensive.
Nice! IMO progress only occurs when there are people willing to take risks and challenge the popular (or mainstream) assumptions about surfboard design and construction.
i stoped shpings for a year now and i get sick in my head, bying boards instead of shping them on my own…
i build a lot of boards in the last 6 years and i will continue with a small bunch of boards per year…
so i am just thinking about how to do, so that they are light and strong enough without all the epoxy polyester thing…
and i really think that it is possible to do with balsa eps and linseed resin. @marke: no lindseed oil. is`t a resin based on lindseed an citron. but in the end its much more flexible than epoxy. but maybe it will be enough to create a layer on the outside wich prefent the wood from breaking under point stressloading
Without epoxy/glass your board will be nothing at all like a Sunova.
Balsa with 1 lb eps will not be strong enough. Too thin and the board will snap, like Surfding said. Too thick and the balsa will crush. You could try a solid balsa with redwood rails like the old boards from the 1940’s, but it won’t be light.
You can try poplar veneer like someone else said, but I think at a thickness with sufficient strength you will not be able to form it properly to the blank.
Paulownia is a great wood for board building, it might work, but I’m not sure you’ll find it in Germany.
I've done 1.5mm marine ply over 1.5lb eps with no glass. It was plenty strong enough to surf but it sucked water in after a while and the bond between the skin and eps gave way in some areas (it wasn't sealed that well).
I've also done 5mm paulownia over vh grade eps (around 3lb density I think) with no glass. Hasn't been surfed enough yet to give me any idea of the durability, but I was tring to avoid what happened with the 1.5lb eps.
i have allergic problems with epoxy. the problem with vinylester is that the indegrients a quite similar to epoxy and you get quit fast an reaction against vinylester…
The Glass Tiger guy posts here at times with the user name gtigger. if you search “gtigger” you might find more info. His construction method does use epoxy and inner glass, so it’s not really a solution to your problems.
The Glass Tiger guy posts here at times with the user name gtigger. if you search “gtigger” you might find more info. His construction method does use epoxy and inner glass, so it’s not really a solution to your problems.
I have made boards with a balsa skin. They would not hold up without a layer of glass on the outside. Balsa soaks yo water like a sponge. My poplar ply skinned boards are very strong and I have had no delam issues with glueing the skin to XPS with Gorrilla glue.
It really is a pleasure not to have to work with glass and resin.
