Many factors affect uniform electrodeposition of polymers, Polymerization  time and potential, monomer species and concentration ,Supporting electrolyte, pH,  additives and so on, all of them influence your uniform electrodeposition, you should give more detailed description.

I’m also agreeing to Prof. Wen. In principle, electroplating is not a simple dip and dunk process. It is probably one of the most complex process known because of the unusually large number of critical elementary phenomena, or process steps involved. There are many factors which affect the quality of the deposits like deposition (polymerization) time, deposition potential or current, depositing species (monomer) and its concentration, medium (supporting electrolyte), pH, additives, nature of the substrate etc. Therefore it is necessary to optimize all these operating parameters to obtain a good quality coating. An appropriative additive can be suggested only by knowing all the other process parameters used for the electrodeposition process. Whereas, the basic knowledge about polymer electrodeposition can be learned from the following references;

Beck, F. Electrodeposition of polymer coatings. Electrochimica Acta 33, 839–850 (1988).

Usmani, A. M. Electrodeposition of Polymers and Coatings. Polymer-Plastics Technology and Engineering 15, 115–135 (1980).

organic surfactants may be the best choice for polymer electrodeposition, in addition to the more interesting information given by the previous answers , I blieved that current is the most controlling factor in the electrodeposition process

I agree with Ali H. Abbar