Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.
"BOTTOM LINE QUESTION here, is whether to lay the sheet cork over the 1/32 to 1/16" bump and shim the track later. Or sand/file and fill now even if I can't ever get it completely flush (which is unlikely)?"
Cap'n,
Do I understand correctly that the problem is a bump rather than a dip or debression? If so, It should be relatively easy to remove it with a sander or surform. Shimming up the track might be required if it is a low spot.
A glued-and-screwed splice plate works very well. Being able to add these splice plates and level adjoining sheets is a good reason to use short risers above the grid or L-girder framework, even for yard areas.
Layout Design GalleryLayout Design Special Interest Group
If at the boundaries of two modules, use leveling screws under the legs. If where two sections of ply meet on the same frame, use a sander or a surform file. Sander is messier, but should do the trick in time. I would take the time to add a suppor under that butt and screw both ends to it so that one doesn't rise or fall with time...make sure it all moves in concert once you have it groomed to your satisfaction.
A surform will provide a more natural looking contour as it dips a bit in the soil/surface around it. Mind you, you'd still have roadbed and ballast to elevate it above the slight change in height you have to manage.
I use the David Barrow "domino" method of benchwork, so the ends of my dominos match up with the same width and height -- I bolt them together. I buy 1/4 inch threaded rod, cut it to length, and then have wing nuts on both ends to bolt the ends together.
Before drilling the holes for the threaded rod, I clamp the two dominos together so that the plywood tops of the benchwork are as even as I can get them (if that means the legs have to be adjusted later so be it). I have some large old fashioned hand screw clamps for this purpose. If you know the Barrow system, I am clamping both the top of the domino and its 1x4 lumber framing -- so you need two large clamps:
If the subroadbed still needs a bit of shimming, I have saved a large supply of those annoying "your name here" plastic credit cards that come in the junk mail.
Dave Nelson
Two things I have done are: 1. shim the roadbed, or 2. use a surform to smooth the cork roadbed over the joint where having a short rise was acceptable.
Enjoy
Paul
Durham"s rock hard water putty. work fast, it sets up quick.
grizlump