Saturday, March 22, 2008

Lettercarving, Part II


Lettercarving is a great way to enhance your work. To carve a letter "O", or any curve, you must know in which direction to slice the wood in order to avoid tearout. The diagram shows you the direction of the cut on both the outside and inside curves. The horizontal lines represent wood grain, the dotted line is the stop cut, and the arrows show the direction in which to slide the chisel or gouge. When you slice in the correct direction, the wood fibers are continually supported ahead of the cut. If you were to cut in the opposite direction, the wood fibers ahead of the cut are too short to support the fibers you are slicing, resulting in tearout.

In the diagram, the points at which two arrows meet are at the top, bottom, and sides and show where you need to switch the direction of your cut. You can start cutting at any of these junctures and stop when you get to the next one. You will need to feather the junctures with very thin slices in order to obtain a smooth transition.

When cutting a curve, the outside wall is concave, and is therefore carved with a gouge, while the inside wall is convex and is carved with a straight chisel (which is always bevel up).

A gouge requires that you hold the handle at a steeper angle in relation to your work surface. A straight chisel is held at 20 degrees, while a gouge is held at 40 degrees. A gouge held at a lower angle will result in a wider side wall that will reach beyond the middle of the letter. As with carving a straight letter in part I, keep the cutting edge of both the gouge and chisel at 45 degrees to your pencil line.

Where the letter is thinner, in this case the top and bottom, the depth of cut will be more shallow, since you are always maintaining the same compound angle with both chisel and gouge.

Once you understand in which direction to cut, based on the grain, you can apply this technique to any letter or design that has curves.

I used a 12mm straight chisel and a 12mm gouge with a 3 sweep to cut the letter.

13 comments:

Anonymous said...

How do you do the layout? Do you use a template or Freehand?

Kari Hultman said...

I used a circle template, but for carving phrases, I key the phrase into a software program, print it out, rub graphite on the back of the sheet, and transfer the letters to my workpiece, like you would with carbon paper.

If you freehand letters, they will look crude, which might be what you're after, as in 18th c. pieces.

Kari Hultman said...
This comment has been removed by the author.
Unknown said...

You do realize that you make it look way easier than it really is?

That is not fair.

Kari Hultman said...

Yes, but because I'm showing photos, you don't get to see how l--o--n--g it takes me to carve!

Shazza said...

VC - are you just using pressure to gouge the wood or are you tapping the chisel with a hammer or something?

Kari Hultman said...

Shazza, I just use pressure with my hands to slice the letters. I only use a mallet with the chisels to chop the stop cuts. Good question!

Anonymous said...

VC,

Thanks for showing Part 2! I am glad to follow along, as this might become part of the toolkit of hand tool techniques.

Vic Hubbard said...

Hey VC,

What wood are you slicing there? For that matter, do you recommend learning on something like a soft pine or would it be easier in a moderately dense wood, like maple or birch?

Kari Hultman said...

Vic, that is sugar pine. Cutting softwood that is tight-grained and straight-grained is easiest, but cherry, walnut, and mahogany are fairly easy to carve. Pine with bold grain is difficult to carve.

Learn from my mistake: DO NOT TRY TO CARVE MAPLE.

It will make you cry like a girl.

Kari Hultman said...

Actually, it was rock maple. It is very difficult to push the chisel through it because it is so hard, so you must make more passes. And it is rough on your tools—you have to rehone frequently.

I also tried to carve oak....once.
But some people like to carve oak and do it very well. I think it is too difficult.

Try a bunch of woods and see what you like best. Maybe you're a maple man, after all!

Vic Hubbard said...

Thanks VC. I'm looking forward to trying your technique.

Kari Hultman said...

Good luck, Vic! It does take a litte practice to maintain the compound angle and ride the pencil line, but just take your time. You will get it.