Does anyone know what density is the EPS core in sandwich boards??
Thanks

Uh! I thought this was about that Irish band - couple of honeys in that. Never mind.

grumplestiltskin said...

sausage said...
I've always wondered why the smaller boards (speed and waves) don't utilise the higher density but much stiffer extruded Polystyrene. I know weight is an issue but the total difference would be minimal on a smaller volume board but much stronger overall. Any thoughts are appreciated (but no red thumbs please)

Dont quote me on this but,
I expect that your right about the strength etc.
the problem is the majority of boards are produced in one or two factories, and they have a process that they follow ... regardless of the size of the board.

if you are after alternative cores etc. you need to seek out the custom build guys.

Grumps,
Good point about board manufacturers - imagine if they built stronger boards that didn't break as easily. No one would need to buy new ones. Ah the old manufacturer's tenet "You won't make any money if you make something that doesn't break"

Don't quote me on this but if extruded PS weighs around 28kg/cubic.m and say there is .08 m3 in a 85litre board this would equate to 2.24kg core weight as opposed to 1.6 to 2.0kg for equivalent expanded PS core. Seriously is this much additional weight that big an issue.

I hear what your saying, but thats not quite what I meant.

what I meant was that because the "big" board manufacturers all have their boards made in one or two factories, that the manufacturing process would therefore be the same for all sizes and models.
i.e. if they use one sort of polystyrene for one, then they would use them for all. Its just an economy of scale.

There are definately different methods.

Dont quote me on this, but I think StoneSurf for instance used closed cell foam for their cores. There boards dont seem to be much heavier, as well as being just as strong.

Horses for courses. If you want something a bit different you have to seek it out

I use 24Kg core for my wave boards, but slalom boards can go down to 13Kg.

I've used extruded styrofoam for a couple of boards, and Blue Juice has made many that way.

When I bought my extruded foam it only came in 150mm thick slabs, and was very expensive compared to the cheap expanded variety.
That comes in a 1200 thick block that about 8-9 boards can be cut from, works out quite cheap.

Last year some time Blue Juice said that extruded foam had gone up in density, about 32kg I think. He was looking around for an alternative, don't know if he was successful.

Then Stone Surf in Gero is using low density urethane, not sure what that is, in the mid 20s I suspect, cause he's making some light boards.

The beauty of the extruded foam is not only it's stiffness but like urethane, it's closed cell and doesn't suck water.