I glued down cork roadbed on my son’s HO layout and there’s one section that has a lump in it. I’ve been sanding it down little by little, but I’m wondering if there’s an easier way to make sure the actual track is free from lumps once it’s laid.
The lump is small enough for me to believe that trains might pass through just fine, but my four-year-old son loves running trains wide open, and at that speed I’m afraid the lump might be too much.
Have any of you had a lump in your cork roadbed? If so, how did you accomplish smooth trackage?
Here’s what I have so far:
I won’t be able to read any replies until in the morning, but I thank you in advance for any help you may be able to offer.
Get a straight edge and lay it on the cork to get a good idea just how much you need to sand. If it is a sharp bump, it could make a bump between sections of track that would cause a problem. If it is a gradual rise and fall, it would be much less of a problem. A long block with a coarse paper should sand off the most of the lump. Since you probably will be covering the cork later, fine sanding shouldn’t be necessary.
Two suggestions:
If you paint your cork a color close to what you plan to use for ballast it will look better until you get to ballasting, usually one of the last steps. Also makes it so you do not need much ballast around turnouts where ballast in the wrong place can cause problems.
Since the engineer wants to run full out I would put a plexiglass safety barrier around the outside of the layout. Directions for making one are available under expert tips, I think. (I’ll check and edit this if necessary). It keeps trains from taking a dive, but as long as your layout is low enough, he should be able to reach over it when necessary.
Edit: Yup, it’s called “Making a Plexiglass Safety Fence”
Sanding is a good strategy for small bumps and irregularities, as it’ll remove that carefully, which is a good thing.
On the other hand, if you have industrial size lumpiness or simply need to form a long incline or transition, I like to use a Surform-type plane. It’s got little cutter nubbins embedded in a steel band, if you’re not familiar with it. You have to be more careful to not take too much off, as it works really well on cork, so check as you go to get things right.
I sanded the cork down until it was almost flat, and at one point it’s nearly gone. I sanded a couple of other spots, too, and hope I now have a roadbed that’s flat enough for smooth trackage.
Actually, you probably didn’t have to seal the joint underneath where the roadbed would be laid. And I use latex adhesive caulk to seal the joints where necessary.
Somehow I am reminded of the old fairy tale, the Princess and the Pea.
To get back to one question the OP asked – do NOT tolerate odd lumps in the roadbed if at all possible. It might be that the track that has integral plastic roadbed under the ties could adapt to a slight bump, but otherwise a slight bump in the roadbed is very likely to translate to a slight bump in the track. Even if it does not cause derailments, it might cause uncoupling, or stalling, and at the very least would be visually annoying.
I use latex adhesive caulk to lay my cork roadbed (versus nails – or rather I use nails or removable pins sparingly and rely primarily on the adhesive). I go over the area pretty carefully beforehand. I use a small wallpaper roller to really get the cork roadbed to snuggle down on the benchwork. That has the added benefit of letting you know when you have a lump or other problem. As an above poster suggested, I then use a very long abrasive block to smooth out the top of the cork roadbed before laying track – which I also use adhesive caulk (and the wallpaper roller) for.
Now having said all that, a superb modeler, Dave Davis, does intentionally introduce irregularities into his roadbed and track to simulate the rocking motion seen on poorly maintained track. A wonderful photo of his layout can be seen here:
