Page 1 of 1

Pauwlonia vs. Western Red Cedar (for a TwinTip core)

Posted: Wed Aug 29, 2018 8:40 am
by flaviocu
Im trying to find Pauwlonia in switzerland - which is more difficult than anticipated. Now one wood-dealer suggested "Western Red Cedar" as core material.
I did not find a lot of references for twintip building on the internet or on various forums (planning on laminating with CFK/GFK). The only comparision I found is from a boatbuilder forum and it seems to be quite similar in its properties to Pauwlonia.

Anybody have any expiriences?

Thank you

KIRI (Pauwlonia) PROPERTIES
Density 0.27 psi
Mod of Rupture 5740-6060 psi
Mod Elasticity 1 million psi
Compressive Strength 3500 psi


WRC PROPERTIES
Density 0.32 psi
Mod of Rupture 5200 - 7500 psi
Mod Elasticity 1 million psi
Compressive Strength 2700 - 4500 psi

aus https://www.boatdesign.net/threads/k...perties.19012/

Danke und Grüsse

Flavio

Re: Pauwlonia vs. Western Red Cedar (for a TwinTip core)

Posted: Wed Aug 29, 2018 9:36 am
by SimonP
Western Red Cedar would be quite a bit stiffer and heavier. It might be OK if it was from a fast growing plantation and harvested at a young age.

Re: Pauwlonia vs. Western Red Cedar (for a TwinTip core)

Posted: Wed Aug 29, 2018 10:01 am
by kiterocky
If u go in Italy in most Brico center u can find 150x50 cm paulonia 30euro or less...

Re: Pauwlonia vs. Western Red Cedar (for a TwinTip core)

Posted: Wed Aug 29, 2018 10:43 am
by flaviocu
:) Unfortunately italy is quite a ride from here, but I will start looking beyond our borders if there's no better option here.

Re: Pauwlonia vs. Western Red Cedar (for a TwinTip core)

Posted: Wed Aug 29, 2018 11:47 am
by nixmatters
Have you compared water absorption properties between the 2?
As for Pauwlonia sourcing in Europe - I recently spoke to a guy named Chris, who makes 'Kilaia' boards (just google or search Facebook for Kilaia and you'll find him). He's buying ready made planks from somewhere in Spain. And it's locally grown Pauwlonia, not imported from Asia.

Re: Pauwlonia vs. Western Red Cedar (for a TwinTip core)

Posted: Wed Aug 29, 2018 12:34 pm
by BWD
WRC is stronger and stffer.
Rot resistant, used for boats, house siding and roofs.
Works easily but doesn’t like to be heat/steam bent.
You can do two layer core for rocker control, just make a longer, thin blank, plane it flat and cut approximately in half - top half can be shorter if you like. Bond layers in rocker jig with epoxy or PU glue, laminate as you like. Can go lighter on glass than paulownia foam etc.
I have made a few wrc core boards. It can work great.
Making a 2 layer core works better than trying to hold rocker by laminating fiberglass over it. To get a little curve by just laminating it in, jig may need to have rocker exaggerated 2-3 times desired rocker. do a test strip before lam of whole board if you go with that method. Can be a guessing game.
If you have the right tools and don’t want a two layer core, cutting curved strips to make the rocker would be a good approach.
Cutting rocker into the strips before gluing up the blank or doing two layer core locks the rocker in from the start, no stress.

Re: Pauwlonia vs. Western Red Cedar (for a TwinTip core)

Posted: Wed Aug 29, 2018 2:31 pm
by Mossy 757
I made an alaia out of WRC and it's much less buoyant than my pauwlonia board, albeit much stronger and heel dent resistant.

Re: Pauwlonia vs. Western Red Cedar (for a TwinTip core)

Posted: Wed Aug 29, 2018 3:28 pm
by phuqit
You can check my thread, I faced similar challenges. If you're building a twintip though, I highly recommend using Airex C70-90 foam instead - it's much lighter (core weight difference was 400g vs 2kg WRC!), and easier to work with:

170x50cm board with WRC:
viewtopic.php?f=107&t=2399912

Airex/carbon build:
viewtopic.php?f=107&t=2400354

I also have 4x paulownia cores from www.junksupply.com lying in my garage, and I doubt I'll be using them...

pq