Adding rocker to an already shaped blank

Thank you everyone for your comments on this post!  I think I may just leave the blank as is and see if this amount of rocker and design works.  If not, then I'll just shape more rocker in next time. 

Thank you!

I recently shaped a new board and didn't build in quite much rocker into it as I had hoped.  This is my 4th board I have build, I have some experience building and I can follow instructions well, but I could use an experts help. 
The board is a 6'10'' step-up board for Ocean Beach San Francisco.   Right now I am at 2'' of tail rocker and 4.5" nose rocker, and would like to be closer to 2.6'' tail rocker and 5.25" nose rocker.  The blank is done being shaped, it's a polyurethane blank with stringer, standard US blank.   Does anyone have any tips or tricks on how to safely bend the board a little more to add some rocker as desired?
Could I try doing some light steaming of the blank, mainly the stringer, and then add some weights to bend?  I am hesitant to do this because I have concerns about getting moisture into the raw blank. But maybe I could do this and then allow enough time for the moisture to evaporate out?  Another idea I had was to hang weights under the board while laminating the bottom of the board, by screwing into the stringer and then going back and filling in with resin. Once the lam hardens, take the weights off and hope the board holdes its shape?

I would really appreciate any experts help on this, thank you!

Is be very curious to hear your thoughts on this and as always, thank you so much for your help! 

I’m no expert on this subject, hopefully more experienced voices will chime in.  I would say this is not a good idea.  If you didn’t get the rocker you wanted before or during the shaping process, I wouldn’t try to alter it now.  

You could probably change the rocker to some extent in the glassing process, but I doubt you could really control the nuances to be exactly the amount you want, and the place you want it, unless you’re vacuum bagging with a rocker table.  

My best suggestion would be to use the board as shaped, and make the changes on the next model.

Given the board size, the nose and tail rockers, I’d say that you swerved into a near perfect set of dimensions.        Don’t change a thing.        Glass it, and ride the S#!t out of it.        Well done!

Well, If the blank is fairly thin at both the nose and tail, you could try this method.

I use it sometimes on my stringerless blanks as they sometimes spring back flatter than what I desired.

Laminate the bottom.

Just after it kicks,

Place some plastic (clear) on nose and tail.

Place weights as close to the ends of the board as possible.

You may have to use more or less weight to get desired rocker.

Watch carefully as it does not take much to add rocker.

Let it sit over night.

Dry lamination will hold new rocker curve.

Can easily get an extra 1/2" or so extra rocker.

Clear plastic will just peel off no problem.


The rocker you ended up with, is a rocker I’ve had excellent results with, both in  Calif.  OH+ waves and  NS  waves up to 15 feet at Sunset.        I’m serious when I say don’t change a thing.       Glass the bottom first.