Thursday, May 28, 2009

Neck Joint Cutting - Almost

Thursday, May 28, 2009.

Well, I am rapidly approaching the end of May and it occurs to me that I have been working on this now for just over five full months. As I look at what I have to show for the time, it doesn’t seem like much. When I look back at this blog, though, the road has been pretty long and I have already learned a bunch more than I ever expected.

I’m good with it and I can only hope you are, too. So lets keep going.

I am a bit disappointed in how little I have been able to get done in the last several days, but its not like I have been sitting still. I glued my soundboard on to the rim and spent a great deal of effort to create a jig for cutting the joint in the headblock where the neck attaches. My disappointment comes from the fact that for all my work, I am not going to be able to use the jig I made but will have to cut the joint differently than I had planned, but I’ll get to that later. At the moment, I want to show you something I came up with.

A couple of annoying little problems I ran into when using the hot hide-glue were that the glue cooled down too quickly and I was having to heat it downstairs in the kitchen and run with it upstairs to use it. When it began to cool off, I either had to run back downstairs again or stop where I was. Not fun. Then one day as I was browsing through the posts on the Mandolin Cafe, I ran across a thread where others were sharing how they dealt with this and other hide-glue problems. One of the things that caught my attention was how some folks make up their glue into plastic squeeze bottles and place steel nuts in with the glue to add weight and hold heat. What a cool idea. So that is what I did.

For my bottle, I took a nearly empty Elmer’s Glue bottle, washed it out, and poured in my heated hide-glue. I then put in four nuts - small enough to go through the mouth of the bottle but big enough to not interfere with the glue reaching the nozzle.

Now that I had an improved glue delivery system, I needed an improved heating system. While I could have purchased a single electric cooking eye or one of the glue pots you can buy at Stew-Mac or LMI, I did not want to spend that kind of money on it. Instead, my wife happen to find a “personal coffee heater” at a yard sale.

Using this, along with a glass bowl of water, I no longer have to run up and down the stairs. This is the rig I used to heat my glue when it came time to glue the soundboard to the rim and I must say I am very pleased with how well and quickly it works.

So, once the glue on my soundboard assembly had dried, it was time to focus on the neck joint.

In Mr. Siminoff’s book, he details two methods for cutting this joint; one method is his own development (the one I settled on) and the other is the classic dovetail joint. In order to cut the Siminoff joint, you need to create a jig that both elevates the head block to about a 6 degree angle and allow it to rotate in both directions so that you can cut a “V” joint with your bandsaw. Early on, as I looked over my bandsaw and the materials I had on hand, I knew that creating this jig was going to be a challenge, but I figured I had what I needed. Sadly, though, I was wrong. Fortunately I never cut into or damaged anything important in the process of learning I was wrong. All I lost was time.

While I was able to eventually cobble together a jig that allowed me to just get the head block up to the saw blade, I found that I just did not have enough room to allow for the rotation without hitting the bandsaw with the scroll.

Even though I was not able to use it for anything other than a learning experience, I decided to go ahead and put up some pictures of how I put it together. You will probably notice that there are a lot of extra holes and cuts that don’t look planned (they weren’t), but I had to take it apart several times before I got enough clearance to clamp, rotate, and cut even as much as I was able.

So now that I realize I cannot use Siminoff’s joint, its time to learn about and attempt a dovetail joint. From what I read, it looks like this should be one I can cut, it simply takes a lot of touch-feel work to get it right.

I will let you know how it goes.

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