Q: The finial on a newel in my home was damaged. I'm not sure what happened, but I'm wondering whether this is something I can fix with a wood filler or whether I should disassemble the finial and replace the damaged part. If replacement is the best option, how difficult is it to do, and where am I likely to find a matching finial?
A: You could replace the missing wood with two-part epoxy, but to give the repair a finished look, you'd probably need to paint at least the cap. To keep the natural wood look, though, you'd need to pry off the cap and replace it.
If you opt for a patch, first cut a plastic putty knife or an old credit card so you can use one edge as a shaper to form the profile you need to match. The plastic needs to have the negative shape if you consider the wood the positive shape. After that, the steps are simple enough: Brush on a bonding agent if recommended with the epoxy you buy, mix the epoxy components, push the epoxy into place with a putty knife or a gloved hand, then shape the fill. Because you need only a little filler, options include the six-ounce kit for PC-Woody wood epoxy paste ($9.45 at Home Depot) or even the 1.5-ounce kit of PC-Woody brown epoxy adhesive ($5.64 at Lowe's).
If you opt to replace the cap, use a thin prying tool, such as the Grip eight-inch pry bar/nail puller ($17.99 at Woodcraft) to remove the damaged trim. You'll need to poke around a bit to figure out whether there is mitered trim around the base that you can remove to give you access for lifting the top of the cap. Or you might find that the cap was installed as one unit. Slip a putty knife blade underneath the pry bar as you work so that you don't damage the post.
It might be possible to hunt down a ready-made replacement at a store that specializes in salvaged building materials, such as Community Forklift in Hyattsville (301-985-5180; communityforklift.org). If you have only one newel post, the replacement cap wouldn't necessarily need to be a perfect match; it would just need to fit over the post and have a style that wouldn't look odd given the rest of the staircase. However, it might be more time-efficient to simply make a new cap in matching wood, which from the picture you sent appears to be oak.
A furniture repair company can make a duplicate piece. Or you might want to investigate using the facilities of Woodcraft of Rockville, through its Woodworkers Club (301-984-9033; woodworkersclub.com) or TechShop DC-Arlington (703-302-8780; techshop.ws/arlington.html). Both offer access to woodworking tools once you have been checked out on safety. If you can't justify the membership fees, perhaps an existing member would make the replacement piece for you as a favor. Or maybe there is a woodworker in your neighborhood or among your friends. Whoever does the fabrication, be sure to save scrap wood so that you can test stains to get as close a match as possible to the post.