How to Make a Scarf Joint

RON HAZELTON:
This antique doll carriage belongs to a friend of mine and he asked me to repair it for him. You can see what the problem is right here. This rail is broken completely in half.  Not only is it broken in half though, there's actually material missing.

Right down here, you can see that.  Well this gives me a good chance to demonstrate something called a scarf joint.  It's the kind of repair I use any time I've got a break like this.  I want it to look good when I'm finished. But even more importantly, I want it to be strong. 

I'm removing the part that needs repair so that I can clamp it flat on my work bench.  I've cut a small strip of oak the same width as this broken rail down here.  What I'm going to do now is lay this on top of the rail.  And then clamp it in place. 

Next, I use a small straight edge to draw cutting guidelines on the strip of oak.  Then, using my Japanese handsaw, I cut through both the oak strip and the carriage part at the same time.

Now here's the piece that I cut out of that strip of new wood and it should just drop right in here.  Yeah. And I've got virtually a perfect fit here. Because I clamped the two pieces together and cut through them both at one time.  Next, I apply glue to the cut edges.

Set the section of new wood in place, then clamp it, first to the bench and then to the carriage part.  I give the glue time to dry. And after that, remove the clamps.  Well at this point, the repair work is pretty much done.

This is structurally sound now. But I do have to clean up the wood and see if I can blend in the color.  These ultra sharp rasps called micro planes allow me to shape and surface the new section quickly. A little sanding smoothes things out and contours the edges.

The original damaged section had a small notch to help hold the axle in place.  I recreate one in the new piece using a handsaw and a chisel.  Now I'm ready for some color.  On small jobs such as this, I find that a furniture touch up marker works really well. I just rub it on, blend it in and dab off any excess.

A top coating of shellac will seal in the stain, provide just a bit of gloss and add a touch of color.  Now you'd really have to look to see this repair.  And not only is it practically invisible, it's strong too.   One antique doll carriage repaired and ready to be enjoyed.