Dentil molding

[Lucas Bittick]

As a newbie, I have my crazed ambitions and irrational curiosities to explore. Can anyone explain dentil molding? What kind of technique is involved in making it? I imagine that the stock is planed to ogee shape, with a protruding revel/rail running the length of the molding near the bottom third. This would then be carved with chisels to create the dentil?

The ready-to-buy dentil moldings frequently are a two-piece construction, with the dentil strip pin-nailed or glued into place. Is this a competitive technique?

Just curious... anyone have experience with this? I am planning a Georgian-inspired fireplace surround, and my mind is racing with questions.

Many thanks!

[Tom Veatch]

Recently completed 6 bookcases with shop made dentil molding across the top. See below. The way I did it was to machine the molding to the proper section; face jointed and planed a 4/4 white oak board to the proper thickness to match the height of the molding and used an ogee bit in the router table to get the edge I wanted. Ripped the edged strip off the board to get the thickness I wanted. Back to the router table for a new molded edge, rip it off at the table saw, back to the router table, repeat until I had as many strips of molding as I needed.

Then put a stacked dado blade in the table saw set to the width of the groove, made a "step and repeat" jig fixed to the miter gauge and and dadoed each groove with a fixed spacing between grooves. Turned out well. At least the wife was pleased.


Oops - Just noticed this was in the Neanderthal Haven - please forgive the blasphemy

[Lucas Bittick]

Not blasphemy at all-- I appreciate the reply! As many have commented, combining old and new methods can make for some great results. That is a very balanced dentil and some beautiful white oak, too.

This is an image of a vintage mantelpiece, which has me scratching my head: how'd they do that?

http://i201.photobucket.com/albums/aa282/LMBittick/Creek/th9111S2.jpg (http://i201.photobucket.com/albums/aa282/LMBittick/Creek/9111S2.jpg)

[David DeCristoforo]

"...how'd they do that?"

If you look closely you will see that the moulding is actually three separate pieces with the middle one being the dentil. The dentil can be cut as Tom suggests with a "step and repeat" jig or laid out and laboriously cut with hand saws and chisels. Your choice. If you decided to machine the dentil, there are many other methods that would work. With hand tools, there is really only one....

[Robert Parrish]

I just finished a curio cabinet from an old issue of Wood magazine which had dentils across the top. The entire cabinet was designed around the dentils so that a full dentil would be seen on each side. All the other pieces were measured from this dentil moulding. The dentils were cut on the table saw using a jig described in the article.

[Robert Rozaieski]

If you look closely you will see that the moulding is actually three separate pieces with the middle one being the dentil.

Yep! This was a very common technique for seemingly complex moldings. Building up a complex molding from simpler shapes is easy to do and can create a myriad of complex profiles. Trim carpenters still do it today. The most common place to see it is in crown moldings and mantles such as yours. You can layer several different stock moldings to create a very nice effect, as you've seen. The simpler separate moldings are also much easier to make.

[Robert Parrish]

Lucas, It was Woodsmith magazine No. 26 and not Wood magazine. Sorry

[Lucas Bittick]

Many thanks everyone for the great responses. I'll experiment with the layering technique and see what I can come up with.

(btw-- I did a google search for "dentil jig" to see if there equipment related to dovetail cutting jigs for cutting dentils. More than half the results involved dentists and dentures. Figures!)

Robert P-- do you plan to post some images of your curio cabinet?

[Frank Drew]

The trick, as you'll note in Lucas' picture, is to have a full "tooth" at each corner, which then miters nicely with a similar piece from the run of dentil along the sides. Depending on the size of your elements and the length to be covered, you might have to play around with spacing on a few cuts to have it come out right. It doesn't have to be done this way, but I think it looks best.

This is a tedious enough job that I wouldn't want to have to do any amount of it with only hand methods.

[David DeCristoforo]

"...btw-- I did a google search for "dentil jig" ...half the results involved dentists and dentures..."

Search again only this time search for "box joint jig". The principal is exactly the same.....

[Lucas Bittick]

Although I am not rushing to make my own dentil molding completely by hand (I don't even have all the molding planes), I wonder about technique with most of the woodworking I see.

Frank--- I was impressed with that mitered tooth in each corner as well. The whole piece is a great example of careful planning and execution. I found the precision of the dentil to be admirable, which led to my wondering how it was made.

David-- tons of results for "box joint jig." Thanks! I thought this method looks simple and effective (it uses a table saw): http://sawdustmaking.com/Box%20Joint/boxjointjig.html

Using hand tools, I envision measuring/marking the dentils, and then removing material with a dovetail saw and chisel. Has anyone ever done this by hand?

[David DeCristoforo]

"Has anyone ever done this by hand?"

Of course! How do you think it was done before there were table saws? I have personally never cut dentil by hand but I've cut box joints by hand. Making dentil "by hand" would have to be a "labour of love" at this point or a "learning experience". If you made enough to trim a room for example, your sawing and chisel technique would benefit hugely by the time you were done. Plus you would have probably mastered sharpening as well, not to mention patience and self control.

[Lucas Bittick]

David C.-- sorry-- my intended question was, has anyone here ever done it by hand?

Sure sounds like a labor of love, as you said...

[Mike K Wenzloff]

Hi Lucas,

I have done dentil by hand on a smaller size-scale than the wonderful mantle you posted. Part of a smaller crown build-up on an otherwise simple wall cabinet.

It isn't onerous to do. It's not as tedious as the box joints by hand that David has done. If you look closely at the picture you posted, those dentils are not perfectly spaced like you would get with a box joint jig. They are wonderfully laid out and executed.

Spacing layout for where they break around a corner is half the battle.

From there, it is resonably careful marking for the full depth into the edge of the board (marking gauge like the baseline of DTs), pencil for the lines from the baseline around the edge back to the baseline on the opposite face. Ensure you color with penciled hatch lines each and every waste section. Saw the lines. Use a fret saw to remove most of the waste right to a skosh above the baseline. A paring guide to help aid keeping the paring chisel square through the thickness of the board. That's all there is. A lot of words for something very simple.

I would expect I could do that length of run in a couple hours. Maybe as many as three, but I don't think it would take that long. Like I wrote, the layout is the hardest thing. This was likely site work, though it could have been done at a shop. The boards for the dentil would be laid in place, the amount of overhang determines, the two ends penciled out and then the spacing of the inner dentils etermined from there.

Take care, Mike

[Robert Rozaieski]

Like I wrote, the layout is the hardest thing.

Agree with Mike that the layout would be the most difficult part, but still not difficult to do. Forget what you know or typically do for layout. That means put down the tape measure and pencil. Get yourself a pair of dividers, a marking knife and a small square. Put a piece of masking tape across the piece to protect it from the divider points until you get them set right. Step off the spaces, adjusting the spacing of the divider until you start and end right at the corner. You want to end up with an odd number of total boxes in order to end up with a full raised "tooth" at each end. Once you have the dividers set, leave a small mark as you step them off, then use your square and knife to mark them, cutting right through the tape. This ensures even spacing along the length of the molding without having to do any math at all. It could be a little tedious for a long piece like crown for a room but for furniture sized work, it's fast and easy. If you want uneven spaces like the molding pictured, step them off from each end. If you've seen the Cosman dovetail DVD, it's the same concept.