purple / black dots between 2d sprites

A friend and I are making a 2D game, one of the features is that a ship will be generated at random, for now we have that a fixed ship is being generated. We place all the parts right next to each other. The sprites have a resolution of 16x16. The first sprite is placed at place 0,0, the next at 16,0, the following row is placed at 0,16 and so on. So the sprites have no gap between them, but we have ran into an issue where if the entire ship is rotated a bit, some purple dots appear around the border of a sprite. Here is an image of the problem. We apply a custom material to each of the sprites, but this material is just the standard Sprites/Default material, with pixel snap turned on. If we do it without the pixel snap, the ship gets a black line drawn through it. How can we prevent the purple dots from appearing in our game?