minimum thickness for std eps layup?

General Discussion
1

Hey, can’t find anything in the archives on this. so without dragging it out, what is the minimum center thickness you can go with a stringered eps blank without having too much flex?

specs: ~25kg/m3 with a 3/16"(4.7mm) stringer in the dims 5’10(1778)“x2”(50mm)thickx20"(500mm)w

the width i am working with is ~20"(500mm) and am carrying the thickness out almost to the rails with a flat deck, and leaving a fair amount in the foil, mostly for floatation.

as you may remember from a post a while ago -“my first eps failure” - i glass the boards pretty heavy 2x4oz bottom, and 3x4oz deck, so have plenty of strength in the laps.

thanks, and if i missed it in the archives, pimp slap as needed…

2

Good flex, bad flex

Small waves, big waves.

old School, new school

Skinny boy, big boy

Front foot, back foot

Boosting airs, trim

1lb Eps,3lbEps?

These are personal questions

In my opinion flat decks & skinny rails have more flex.

Beefy rails domed decks are a lot stiffer.

Add glass =stiffer

More than one way to skin the cat.

Burt Burger went into the 2" range on compsands.

Have fun,

Ian

3

i think 6,6,4 deck 6,4 bottom

if you want thin you need to go into composite boards

4

Hi

Did a 2.4 inch on 2# or 30kg/m3 with 6/4/4 + 6/4 bottom. Found it a tad too much for weak grovelling surf.

Will try lighter and thinner next time for sure.

Wouter

5

Hey Rob,

UK now? I must of missed something!

Your foam is about 1.5 eps…very light.

I think Silly had it…4/6/4 or 6/6/4 top, 6/6 or 6/4 bottom.

For #2 eps you can go as light as 6/6 top, 6 or 4/4 bottom.

Two inches thick for a 5’10 is ok…2.25 would make it stiffer and ‘maybe’ less snap prone.

I know some guys in central FL that make theirs 1.75 thick but they can afford to break them.

HTH

6

hey craftee,

yeah man, made the biggest moves lately. first to brasil, now in the UK. trying to get to my feet here, and thinking about staying for a while. there is quite good surf, despite the reputation of the area. i am in the north east, and scotalnd is only a few hours in the car, plus all the islands off the west coast get hammered with waves. just planning to do some experimenting with shapes/materials and hope to set up a small shop for a few boards a month, if i am lucky…

anyway, how’s the east coast these days?

thanks for all the responses. i have made a few stringerless eps boards, around 2 1/4" thick, but put a slight dome to the deck, and 3x6oz deck, and 2x6oz bottoms. Am still riding one now that is 6 months old and no problems. but creased another one about 2 months after making it in some shoulder high shore pound.

i was considering going into composites, but didn’t want to go the compsand route. at least not just yet. i would prefer to keep it glassed normal though because i like doing the resin work like the old days.

i guess the only way to find out is to ride it as much as possible…

thanks again. its funny. i posted on the …ER BB and got 1 response in 2 wks. i guess i should have said it was a …lost quad fish or something…lol