Hws planning 3mm rib 6mm spine 4mm skins

General Discussion
1

Hello all,

I’m planning my first hws.
Obviously I don’t want it to collapse but I’m after a lighter weight hws . …who isn’t?
I just want to know options on strength of the planned lay up (bottom skin up);
-4oz
-4mm Paulownia skin
-2oz
-3mm rib (6" spacing)/6mm spine made of marine ply)
-4oz Carbon vector net
-4mm Paulownia top skin
-4oz
All with keyline epoxy, I have used this resin and found it super user friendly so far.

I will just use circles to lighten the frame.

Shape 3d for the design.

Rails will be 6mm X 6mm square strips.

All opinions are welcome.

Thanks in advanced everyone.

Enjoy all

2

Hi there,

3mm ribs are quite thin. Remember that you need glue surface as well. You can add some strips to the “corners” where skin and rips meet so you have more glue surface.

4mm Skin is also quite thin but should be ok when you glass inside and outside.

Marine ply is quite heavy, I use birch ply with thicker ribs/spines. You can double check what comes out lighter

If your construction is sturdy enough I am not sure to be honest. but should be ok. I use 6mm skins and 10mm ribs/spines with triangle shaped cutouts and only outside lamination, as a reference

But give us some progress reports how it goes :slight_smile:

3

The biggest mistake HWS builders make is not putting nose to tail strips under the deck.
You need 4 strips, 2 about 3’’ out from centre spine running 3/4 the length of the board and 2 more shorter pieces 3’’ out to handle knee dents.
10mm by 10mm is what I use, note in the piccy below I glue 5mm by 5mm pieces to the sides of the ribs top and bottom to give 15mm of gluing surface for the deck skin, very important.