Newel Post Cap

Newel posts are the support posts for handrails or stair banisters, located at the ends of the banister, as well as anywhere there is a corner that the handrail must go around. But that’s not what the word originally meant. It was a much more specific term, applied only to spiral staircases. In that case, the newel post was the central supporting post for the staircase. Today that earlier definition has been lost, as we rarely use spiral staircases and commonly build regular staircases with handrails.

A large part of the reason why newel post caps are used is purely decorative. Leaving the end of the post cut off square, with the end grain showing just isn’t all that attractive. But there’s a practical reason for covering that end grain as well. That’s because the end grain soaks up moisture 100 times faster than the long grain, so leaving it exposed creates a condition where the top end of the newel post will be constantly expanding and contracting with changes in the moisture level. Sealing that end grain with paint or varnish is difficult, as it can soak up a lot of these finishes.

Newel posts come in a wide variety of styles, including some very fancy carved ones. But the basic styles are flat, peaked, ball, a spade (which is like a rounded pyramid) and a king cap (which looks like the top of a chess king). Carved ones can look like anything that can be carved out of a block of wood; but most are floral, leafy designs of some sort, although I have seen squirrels and birds as well. All of the styles of newel caps can be made out of any type of wood, as well as cast in metal and molded out of urethane. For home interiors, wood is the most common.

Some newel posts come with the cap cut into the post when purchased. This is pretty much only done with a ball type cap, as flat or peaked caps normally extend past the edges of the post. But even then, the existing cap can be cut off and a different style of cap installed.

Installing a Newel Post Cap

At first glance, installing a newel post cap may seem difficult for those who have never installed one before. That’s mostly because the installation hardware is hidden, if the installation is done correctly. In most cases, newel post caps can be installed in no more than a few minutes. On the other hand, it can take longer to remove a newel post cap than to install one, in the case that they are being replaced.

Due to their location, newel post caps receive a lot of handling, as people go up and down the stairs. This can lead to excessive wear, necessitating their replacement long before the posts need to be replaced. When that happens, the biggest problem is often figuring out how they were installed originally, so that the newel post caps can be removed, without causing excessive damage to the posts themselves.

There are three basic ways in which newel post caps are installed:

Adhesive

The simplest way of installing newel post caps is to use construction adhesive alone. A dab of construction adhesive is put in the center of the top of the newel post and the cap is pressed down upon it, spreading the adhesive and ensuring that it makes good contact with both the post and the cap.

While this is a simple method of installing newel post caps, it is the least secure method available. The adhesive is attached to the end grain of the newel post, where it can’t get a good “bite” on the wood, especially since construction adhesive is a heavy-bodied adhesive with high solids content. On the other hand, it is usually fairly easy to remove the cap if it needs to be replaced, as the glue can be pried loose.

Dowel

Some newel caps come with a dowel base, intended to be glued into a matching hole in the end of the newel post. This is the most secure method of mounting, as the dowel provides a large long grain surface for gluing. This sort of mounting is used most commonly on round ball type newel post caps, without a base molding.

The problem comes when the newel post doesn’t have a hole drilled into the end of it, for the newel post cap to mount into. This really isn’t a big issue, as it’s not all that hard to drill a hole. Just make sure that the hole into the end of the newel post is absolutely straight.

When replacing this sort of newel post cap, it is necessary to cut through the dowel. A thin kerf saw, such as a Japanese pull saw, cutting just at the base of the newel post cap, is the best way to make the cut. It will probably take some time to cut, as this will have to be done by hand, rather than using a power saw of any sort.

Nails

The most common method of installing newel post caps is with nails. This can be done with round newel post caps without any molding around the top of the cap, but it is most commonly used with square caps which have that molding. The cap is set in place and a pneumatic finish nailer is used to put one nail in each side of the molding, down near the bottom, in the center of the side.

This is the hardest type of newel post cap to remove, often requiring breaking up the cap, as the nails are not accessible to be removed. But since the cap is being replaced anyway, it really doesn’t matter if the cap is broken up in the process.

Is it Possible to Make Newel Post Caps?

While most people buy newel post caps that have been factory made, it is possible for the woodworker to make their own. This is especially advantageous when several caps are needed, as the cost of buying that many caps can be daunting. There are several ways of making one’s own newel post caps.

Round Ball Caps

The various styles of round ball caps, including king caps and queen caps require the use of a lathe. However, if one has access to a lathe, they are extremely easy to make. Much like any other finial, it’s just a matter of turning the ball or other shape out of the blank.

But what if a square base is required, with the ball cap? That’s really not any harder. The main difference is that the square base will need to be routed to give it an appropriate profile, after the ball has been made.

turned post cap
Turned post cap

Using the drawing above as an example, a 5”x 5” x 6” block of wood could be mounted to a faceplate so that a dovetail mortise could be turned into the bottom of the block. Once that was done, the workpiece would be removed from the faceplate and mounted into a chuck with dovetail jaws. The ball could then be turned for the top of the newel post cap.

Once the ball and the ring at its base are turned, the workpiece is removed from the lathe so that the base can be worked. One thing to keep in mind when thinking about making newel post caps in the workshop is that router bits can often be used in combination to make more complex profiles. A router with a straight bit is first used to cut out the pocket in the bottom, shown by the dotted line. Then various other bits can be used to form the “molding” on the edge of the base. In this case, a roundover bit would first be used to round the top edge. Then a beading bit could be used for the lower part of the cap. Finally, a round bit could be used to cut the indentation into the side.

Of course, all this is going to require considerable sanding and then the newel post cap will have to be finished; but then, that’s part of pretty much any project.

Peaked Newel Post Cap

Other than ball newel post caps, probably the most common style of post cap is the peaked cap. This is also something that can be made in the home workshop, even easier than the ball cap above. It can either be made as a solid piece, like the ball above, or made in pieces, which are then assembled to make the complete cap. Let’s look at how it can be made in pieces. I’ve made the drawing below as an exploded view, to more easily show the different parts involved.

peaked post cap, square base, newel post, cove molding
Peaked post cap

For the best possible look, both the peaked cap and square base should each be made of four pieces of lumber, mitered and connected together. This will eliminate any visible end grain, making a better newel post cap. But to be honest with you, no factory is going to make newel post caps which are made of four pieces of wood laminated together to avoid end grain. So if you don’t do that, you won’t be berated for it.

Of those pieces, the one which it would make the most sense to build out of mitered pieces would be the square base. Cutting four mitered pieces and gluing them together, perhaps with pocket screw from the bottom side to hold the pieces while the glue dries, will make the post cap more attractive. But again, that is not required.

However, if we’re trying to avoid using a router, this design is ideal. The square base can be made from stair treads, which come with a rounded edge on them. miter cutting four pieces and then assembling them into the square gives a rounded edge all the way around.

The other option is to start out with a single piece of wood and rout the edges, much like we discussed for the ball post cap above. Any molding design can be used, depending on what router bits are available. However, it is not necessary to make this very complex, as the piece of cove molding below the base provides the molding effect. Any sort of baseboard or casing could be used in place of the cove molding, depending on the look desired and the molding available.

If any miter joints are used, either in mitering four pieces together to use molding below the base piece, then there is always a chance of ending up with some small gaps between the pieces. The normal way of dealing with this is to use wood putty to fill the cracks; but there’s a better way. Save some of the sawdust from the wood and mix it with wood glue to make perfectly matching wood putty, filling the gaps with that. Keep in mind however, that this will not stain well, if you’re planning on staining the wood.

The top, peaked piece of the newel cap is cut on the table saw, standing on edge and setting the blade at an angle. A jig is needed for this, so that it can support the workpiece and keep it from falling into the saw blade. That won’t be much of an issue for the first cut, but as more sides are cut, the chances of the workpiece falling into the blade and being destroyed increase.

The jig needs to surround the workpiece on three sides, the top and the bottom, with the workpiece standing on its edge. The fourth side of the workpiece will sit on the table saw’s table and must be flush with the bottom of the jig. The jig must also ride against the saw’s fence, establishing the distance the workpiece is held away from the fence, so as to ensure that it is the same for all four sides. Make sure that the workpiece fits snugly enough into the jig that it won’t slip while cutting.

peaked post cap jig, pivot screw, jig, saw blade, workpiece, saw table, saw fence, holder
Peaked post cap jig
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