what's the best way to build CERTER-FLANGE on MOLD??

[seamonkey]

.....I'm assisting on a 28' sailboat project,,,the hull plug is near completion,,,and the plan is to attach a 6" woodpeice down the centre(using molding plaster),,,,,then spray tooling gel on one side of the mold/flange,,,do FULL glass lay-up,,,,then remove the wood,,,then spray/layup the other side.
I'm a bit concerned about doing FULL layup on one side of the (somewhat frail)plug before touching the other side.
---IS THERE A BETTER WAY?--should we skin the one side,with partial layup,then do the full thickness layup through the flange area,,with layers feathering outwards,,,,then get the other side going,,,and come back to the first side to build the bulk more evenly??????
---OR IS THERE A BETTER WAY STILL????......thanks!