Need some advice. As you can see from the picture attached, the surface of my layout shows a grid. I used foam board pencils but overlooked that pressure to mark it would also leave wonderful channels in the top. Was great for planning/validating placement of track, etc., but of course, paint doesn't fill in the dents. Also, you'd think at my age I would realize that when primer is suggested, I would use primer...nooooo, I'm too smart for that. Well, even after two coats faint black lines show through. I used sculptamold to fill in the valleys caused by the tapered foam board (I didn't realize it came this way...) but after that experience the thought of spreading that over the entire surface seemed out of the question. So, I've read about using a very light skim coat of Hydrocal, or or some other plaster to do it. I thought of joint compound but in all these cases I worry about cracking. Oh, another solution I used causing an issue: foam board joints. I decided to use Tyvek tape thinking that would be best to assure no cracking. I still believe that's the case, but it doesn't paint easily and it stands out when painted. One final point. My benchwork is MIANNE (7x16) which I love but it does have a bit of motion when you lean on it.
So here's the advice I need: (1) what would be best to use, Hydrocal, plaster, joint compound, something else and (2) if I take that approach, am I likely to end up with spider cracks galore over time?
Thanks,
Ed