Building a Stitching Clam - Bending the Jaws
- mabernet5
- Nov 7, 2025
- 4 min read
Note: One aspect of the build I don't plan to document in here is the creation of the form I use to bend the jaws of my clams, simply because I don't plan to create a new form anytime soon. However, this step is not overly complicated. My bending form is constructed from MDF. The desired curvature was sketched out and transferred to the form material, Enough pieces were cut to give the desired width that the form could accommodate. My form is about 4.5 inches wide. If I can find enough old pictures, I may make a separate post about it.
The first step in any one of my builds is to bend the jaws. At a high level, this involves clamping wood within a form to generate the intended curvature of the clam jaws. There are several ways to accomplish this:
One method is through steam bending. This is be done by first creating a steam chamber, and steaming a single piece of wood to make it pliable enough to bend and then clamping in the form.
Another method is through bent lamination. This method involves starting with thin veneers and clamping a number of these veneers together within the form with an adhesive. The glue helps the piece retain the shape of the form
I've used both methods (or at least elements of both) in my builds. During earlier builds, I worked with 1/8" veneers that I steamed before gluing up and clamping in the form. However, using this approach I observed a few issues with consistency. Notably, several of my attempts warped after removing from the form, rendering them useless. I did have some success, but the end result wasn’t predictable enough for my liking.
Instead, I'll describe my current approach, which solely uses bent lamination to achieve the target curvature:
Step 1: Selecting and Dimensioning the Bending Stock
The process starts with bending stock. I typically start from veneers that are 1/16" or thinner. At this thickness the pieces are pliable enough to glue up the veneers within the form without first steaming, and there are enough layers that springback of the wood after removing from the form is minimal to none. With the veneers in hand, I like to dimension the stock to be a bit wider and longer than what I think I will need. Having pieces that are too wide or too long at this stage isn't a deal breaker, it's just more difficult to trim them down accurately once they're all curvy.
While dimensioning, I like to check the grain orientation for any features that may be desirable (or undesirable) to showcase in the final product. For instance, if there is a knot I might pick a different veneer as the "face" veneer and stick the knotty piece as one of the inner layers of the lamination. I also find it helpful at this stage to use a long straightedge to draw a line to reference as my target final width. This will come in handy later when paring the piece down to size.
Step 2: Prepping the Form
Before I start the glue up, I make sure I have an area prepped for the lamination. This means first and foremost having the form already set up where I'll be clamping. Secondly, it means having all the clamps needed on hand. I like to have my pipe clamps adjusted to the size of the form so that when it's time to clamp there are minimal adjustments being made "on the fly."
Step 3: Glue-up and Clamping
With the form and bending stock prepped, the glue can be applied to the laminations. The more laminations you have, the longer this step can take, so it's important to have an adhesive that has a long working time so that it doesn't start to set up on you prematurely. I use Gorilla Glue Waterproof Polyurethane Glue, but there are several options available. One key tool here is the glue roller as this helps immensely with spreading the glue quickly and achieving an even application.
With glue applied to each of the veneers, the pieces are stacked and set on the lower half of the form. At this point it's important to align the veneers in the center of the form and to carefully place the upper half of the form while maintaining this alignment. Here it pays to take your time and maintain good alignment while you apply the clamps. And speaking of clamps - don't skimp out here. Consistent clamping pressure along the length of the form helps ensure that there are no gaps in your laminations.
Step 4: Cleaning up the Jaws
When the jaws are removed from the form, chances are there will be some glue squeeze out and rough edges. This can now be cleaned up. The easiest way to do this is by running the piece across a jointer, but it can also be done with a hand plane. I start by placing the jaws in a jig designed to hold it for hand-planing (since the stock is bent, a simple planing stop does not work here). The excess glue is first cleaned up with an old chisel. Once that is done, a smoothing plane is used
to gradually pare the width down. This is where having the reference lines (see step 1) come in helpful as they allow you to check that you are keeping the piece straight and maintaining a consistent width throughout. This will make your life easier down the road when it comes time to add a taper to the jaws and to ensure that the mouth of the jaws closes securely
After this step, the jaws should be ready to add a taper and to cut down to their final length. More to come on this in a later post...
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