Contact   Imprint   Advertising   Guidelines

Plywood sandwich rocker spring back

Here you can exchange your experience and datas about your home build boards
jmanindo
Rare Poster
Posts: 8
Joined: Sat Dec 13, 2008 7:19 am
Local Beach: Lincoln City Oregon
Favorite Beaches: The bay
Style: Old school surf
Gear: 11 # 7m Slinshot TD's, Slinshot twin tip
Brand Affiliation: None
Has thanked: 0
Been thanked: 0

Plywood sandwich rocker spring back

Postby jmanindo » Mon Dec 27, 2010 10:38 pm

I am planning to laminate 2 6mm pieces of Baltic Birch plywood together on a rocker table. I want to net 1” of continuous rocker. I would like to know from some of the plywood builders out there if they have experienced loss of rocker or spring back after gluing. If so, any advice on overcompensating during glue up.
Thanks, Steve

User avatar
zob
Frequent Poster
Posts: 476
Joined: Tue Feb 24, 2009 1:43 pm
Local Beach: Grado Pineta (IT), Fossalon (IT)
Style: Freeride, strapless hooked-in
Gear: FS S3 19m2 DLX, S3 CE 12m2 DLX & S4 8m2 DLX
Homemade Surf & Snow Boards
MBS Pro90
Location: Iv.G.-Slovenia
Has thanked: 21 times
Been thanked: 3 times
Contact:

Re: Plywood sandwich rocker spring back

Postby zob » Tue Dec 28, 2010 11:02 am

Naturally, you will get a spring back. I use 2,5 mm ply and it gets spring back, but after bonding the top core layer and laminating it, it holds almost correct shape. I am not so sure about 6mm ply.

If you are doing only ply board- from 2 layers, you should make the rocker about 30% bigger because of the spring back.

BWD
Very Frequent Poster
Posts: 3849
Joined: Thu Jun 05, 2003 3:37 am
Has thanked: 2 times
Been thanked: 81 times

Re: Plywood sandwich rocker spring back

Postby BWD » Tue Dec 28, 2010 5:03 pm

I would agree with zob.
Wood usually springs back about 25-30%.
Sometimes a little more.
Make sure you leave the board on the table (or clamped, weighted, whatever) for a long time so the glue is fully hardened, especially if you use epoxy, and in cooler weather.....
With epoxy, even though it seems hard after 8 hours, boards can lose their rocker if taken off the table early. I try to leave laminated boards on for >24hours, 48h if I have the patience....


Return to “Gear Builders”

Who is online

Users browsing this forum: No registered users and 85 guests