Best process to 3D print electronic card casing

Hey , we’re looking for advice on achieving waterproof electronic card casings, since we’ve faced a few challenges lately. We’ve iterated several manufacturing processes: SLA, which resulted in warping due to thin walls, and MJF, where we removed the ESD constraint but still encountered issues with water ingress through porosity. A topical spray was tried to seal the MJF part, but the result was uneven, with a slightly sticky surface. Can anyone recommend a material or finish that would provide effective waterproofing while maintaining lightweight and cost-efficiency? We’d prefer to stick with additive methods for design flexibility and lower production volumes.