Contact   Imprint   Advertising   Guidelines

Wood Board Spring Back

Here you can exchange your experience and datas about your home build boards
kriskris
Medium Poster
Posts: 66
Joined: Wed Nov 21, 2012 1:32 am
Kiting since: 2003
Weight: 162
Local Beach: Crack Park
Style: Foil
Gear: 633 Onda Peak4 8,5,4,3m
Brand Affiliation: None
Location: Satellite Beach, FL
Has thanked: 11 times
Been thanked: 2 times

Wood Board Spring Back

Postby kriskris » Wed Nov 21, 2012 2:24 pm

Hi everybody,
I tried to build wooden board with poplar core. I used my home built pneumatic press.
My board is 132 cm, 8-9 mm in the middle and 2-3 at he tips. It came out with almost no rocker. What is your experience with spring back? How much should I correct the rocker table for poplar or cedar core with fiberglass layup? Thanks. kris

BWD
Very Frequent Poster
Posts: 3848
Joined: Thu Jun 05, 2003 3:37 am
Has thanked: 2 times
Been thanked: 81 times

Re: Wood Board Spring Back

Postby BWD » Wed Nov 21, 2012 3:00 pm

Rule of thumb for laminating wood is to lose 30-50% of the curve in a lamination of 2 pieces.
For a 9mm cedar board with 18oz (600gsm) e-glass and a medium-modulus surfboard epoxy cured at room temperature, I have found the rocker loss to be about 50%.
It is critical to get a full cure of the epoxy.
Even with fast hardener, with a room-temperature cure I leave the board on the table for several days before removing it!

kriskris
Medium Poster
Posts: 66
Joined: Wed Nov 21, 2012 1:32 am
Kiting since: 2003
Weight: 162
Local Beach: Crack Park
Style: Foil
Gear: 633 Onda Peak4 8,5,4,3m
Brand Affiliation: None
Location: Satellite Beach, FL
Has thanked: 11 times
Been thanked: 2 times

Re: Wood Board Spring Back

Postby kriskris » Thu Nov 22, 2012 12:58 am

Thanks BWD. Correct me if I am wrong. You are saying that with this type of lay up you have to double the rocker dimension to get expected curvature at the tips?

BWD
Very Frequent Poster
Posts: 3848
Joined: Thu Jun 05, 2003 3:37 am
Has thanked: 2 times
Been thanked: 81 times

Re: Wood Board Spring Back

Postby BWD » Thu Nov 22, 2012 2:21 am

Yes. Approximately. Last board was 9mm cedar, 3mm tips, 600gsm glass, epoxy. About 5.8cm on table, final result 2.8cm. The tapers only run from the middle of the strap.positions to tips though. Between straps the center is all full thickness. If the tapers ran a little closer, say to the inside inserts, the rocker might hold a bit more easily.....

kriskris
Medium Poster
Posts: 66
Joined: Wed Nov 21, 2012 1:32 am
Kiting since: 2003
Weight: 162
Local Beach: Crack Park
Style: Foil
Gear: 633 Onda Peak4 8,5,4,3m
Brand Affiliation: None
Location: Satellite Beach, FL
Has thanked: 11 times
Been thanked: 2 times

Re: Wood Board Spring Back

Postby kriskris » Sat Nov 24, 2012 4:30 am

Thank you BWD.

User avatar
vol
Frequent Poster
Posts: 231
Joined: Sat May 28, 2005 6:18 pm
Local Beach: Tarifa Spain
Favorite Beaches: Tarifa Spain, Prassonisi Rhodes, Brazil Taiba-Cumbucu-Paracuru
Style: hydrofoil, bigair, freestyle
Gear: Saul Custom Boards
Location: Tarifa Spain
Has thanked: 9 times
Been thanked: 14 times

Re: Wood Board Spring Back

Postby vol » Fri Dec 28, 2012 11:11 am

Keep rocker helps 2 layers of glass fabric on top and bottom, and BWD is right, If you use room temperature keep board in press 2 days at list


Return to “Gear Builders”

Who is online

Users browsing this forum: No registered users and 55 guests