Well you should always use a sealer first anyway as applying the melamine direct to the wood does not have the desired effect, cellulose sealer is probably the best. But then you do have a potential problem, any moisture in association with cellulose based finishes has a tendency to cause bloom, a whitening of the finish, so that might be an issue. Best way to find out though is suck it and see, i.e. try a piece and see what happens.