Hollows & Rounds – No Way

IMG_0339In woodworking, joinery and casework are important. But just as in life, the devil is in the details. Great casework without strong moldings leaves the project lacking. This is especially true on tall case clocks. The hood’s scroll moldings dominate a clock, but it’s the other moldings that carry ones eye upward to the hood. Poorly designed base-to-waist moldings or shabby cove moldings used to support the hood can destroy the line of a tall clock.

Of the “other” moldings on clocks,  the base-to-waist cove on tall case clocks, due to the thumbnail edge detail, is a difficult molding to reproduce using power tools – you cannot add the thumbnail using round-over router bits as that would require that you invert your molding as it runs past the bit. It is with this molding that I most often thought that I may benefit with a set of hollows and rounds, handplanes specifically designed to produce moldings.

IMG_0330With all this in mind, I set out to find an easy way to make the moldings for my clock using power tools. The first step was to sketch the design I was after. Because I needed to move out 1 5/8″ and up 2″ I decided to use a 30/60/90 triangle design. The two parallel lines in my rather crude drawing represent the 3/4″ thickness of my workpiece. The thumbnail is oriented as it fits to the clock case. After I had the design drawn to scale, I transferred the profile to the ends of my milled stock.

NEW_IMG_0331

The next step was to setup my table saw to make the cove cut. I set my blade height to match the arc of the drawn cove then skewed the fence so the blade entered and exited the cut at the two points of my profile (shown in the insert photo). Above you can see the long fence as it is skewed to produce the cove that I needed.

IMG_0334Take a look at the end results as the pieces are complete at the table saw. My cove is offset to one edge of the stock. It is this beefier edge that becomes the thumbnail area. With my fence back in use, I set the blade angle to 30 degrees. My first cut was with the stock standing vertical to my fence and the cove facing the fence. This removed the extra material at the top, back edge so my molding fit tight to the waist of the clock. A second cut, with my cove facing up, produced the flat area that fit to the top edge of the base section. Below you can see the results.

IMG_0335

Next I moved to my router table to form the thumbnail. As I mentioned above, you cannot use a round-over bit to make the thumbnail unless you run your stock inverted and you have the router bit set extremely high above your table. It’s dangerous and I do not suggest you work that way. Instead, look at other router bits you have at hand. I have a 1/2″ bead bit that is perfect for this operation. In the photo below you see how I have the bit set to cut using only the top half of the profile. You also see a neat trick when you do not have a fence that offsets.

Insert 2

Calculate the amount of material removed as you make your cut, then on the out-feed side of your fence, clamp a scrap that is sized to the exact thickness. As the cut is made, your molding runs tight to the scrap and is supported throughout the cut.

A little light clean-up work and my new cove molding was ready to fit to the clock. I mitered the two corners then added a small bead along the top edge to complete the profile shown in the opening photo. While this takes some calculations to get the profile to perfectly fit into position, it is way faster than making the molding with hollows and rounds.

IMG_0338

Build Something Great!

Glen

2 Comments

Filed under Design, Power Tools, Routers, Shop Tips

2 responses to “Hollows & Rounds – No Way

  1. Mitch Wilson

    Glen, how about a hybrid method? Use the table saw to create the large cove, then use H&Rs for the rest. Using only the router table is very fussy and somewhat lethal. Maybe you can get Matt Bickford to provide some extra insight for all of us here.

  2. Dave

    Great article on how to complete a task & move on with the project construction vs an article talking about spending all those hours doing that work by hand!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s