Yes, that's what I *think* I'm trying to do. Give the chicks a firmer place to stand. The screen in indeed smaller than 1/4". I'm not used to working with 1/4" but I use 1/2" hardware cloth a lot and after the chicks are a couple of days old they seem able to stand on 1/2" pretty easily. But they need something a little smaller at the first.That sounds good. If the mesh holes in the bator are less than 1/4", it should be fine without the liner. You just don't want the holes to be big enough for the chicks to catch their hocks in and mess their legs up. Just thought I'd throw that in...
Anyway, thanks for all your help.