How To Duplicate Custom Molding

Brent Hull, millworker and owner, Hull Historical, replies: When none of the offerings at the home center or the lumberyards measure up, then it’s time to go the custom route. A millwork shop can make special “knives” and turn out an exact duplicate of your existing moldings. The problem is, you have to pay setup fees, which increase the linear-foot price significantly and may not be cost-effective for a small order like yours. The way to avoid those charges is to make your own profiles using a table saw, band saw, and router. On the next page, you can see all the steps I follow in order to copy a short piece of baseboard cap. The process isn’t difficult, as long as you’re familiar with and respectful of these powerful tools.

Trace the Profile

Pry or cut off a piece of the molding you want to copy. If it’s caked with paint, strip it down to bare wood. Take a piece of wood slightly longer than you need and cut it down on the table saw to match the height and thickness of the molding you’re copying. Trace the profile of the original onto the end of this blank. If the wood will be stained, choose a blank of the same species as the original.

Rough Out the Shape

Put the end of the blank next to the blade with the waste side facing down. Adjust the blade height to just graze the pencil line. Mark that spot and set the fence so the cut will hit the mark. After making the cut, turn the saw off and adjust the blade height to a different spot on the profile. Move the fence slightly and cut again. Repeat until the profile is roughed out.

Rout the Bead

For certain details, like this bead, it’s faster and more accurate to shape the profile on a router table than to use a table saw. The critical part is setting the router table’s fence and the bit’s height. Test-feed the end of the blank into the spinning bit and make adjustments until the bead detail is in exactly the right spot. Then rout the entire molding.

Cut the Sanding Block

The roughed-out profile needs to be sanded to eliminate saw-blade and router-bit marks. You can hand-sand simple moldings or make a custom sanding block. Trace the profile onto the end of a short piece of scrap that’s big enough to grip comfortably. Use a band saw to cut along the profile line.

Sand

Check how well the rough molding and the block fit together; trim the block until they mate up. Stick 80-grit sandpaper to the sanding block with double-sided tape and smooth out the rough molding. Replace the paper as needed. Finish sanding with 100-grit paper.

Check the Match

Actually, you’ll be checking your progress against the original piece all along, just to make sure your cuts are accurate. By this point, if you’ve done all your work without going inside the pencil line, your new molding will blend in seamlessly with the old.