Q. I was recently asked to add a cherry base cap along the finished stringer of a custom staircase that makes a broad sweeping curve along the wall in several places. What's the best way to make this molding? Should I use a softer, more pliable wood and stain it to match the cherry? Your help is greatly appreciated.
A. Associate editor Dave Frane responds: If I were doing the project, I'd laminate a curved cherry molding off site.
The most straightforward way to do that is to rip the milled stock into narrow strips that can easily be bent, then glue-laminate the strips around a curved form. The form can be a doubled-up piece of 3/4-inch plywood with a curve cut on the edge, or a series of 2x4 blocks screwed or tacked to a sheet of plywood or a workbench top.
The idea is similar to using bending rail stock to make a curved handrail. If you need an 8-foot length of curved basecap, start with three 8-foot straight lengths and rip them until the profile of the stacked pieces matches that of the original molding. You'll have to account for the parts of the molding lost to the table saw kerf, which is why you start with extra pieces.
Glue the ripped pieces together on the form and hand sand the finished piece to the final profile. This will take a lot more elbow grease than other methods but requires no special equipment. Yellow glue is okay if you work fast, but I prefer epoxy because it sets slowly and spans gaps. Put plastic under and behind the strips so you don't glue them to the form. Use plenty of clamps to avoid gaps in the finished molding. Tight joints between laminations mean that less glue will show, which will make for a better-looking molding.
The curve on the form should be tighter than the curve on the wall because the molding will spring back slightly when it comes off the form. The amount of spring-back is related to the number of layers in the lamination: The more layers, the less spring-back.
