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Author:  Kelby [ Fri Apr 01, 2005 4:31 pm ]
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I'm a little frustrated this evening. Looking for a little venting and a little advice.

First, a little venting. I ran into two problems tonight.

Problem 1: I'm helping a buddy build a dreadnought. Last time he was over, we set the neck (a dovetail joint). He was over tonight, and we discovered that the neck clamped in a little deeper during glue-up than it had during dry clamping, such that the neck was set about 1/16 too low. Also, the angle that the neck set during glue up is just a hair lower than it should have been. Bottom line, the neck needs to be removed. I know it's not that big of a deal, but I haven't ever had to remove a neck before, so I will now have to build a jig and a steam set-up. They are tools I needed to have anyway, but I would just as soon have done without a little while longer.

Problem 2: As we were cleaning up for the night, I picked up another guitar I have been working on (finished, waiting for bridge & string-up) and discovered a problem I wasn't expecting --- some strange ripples in the finish on the back. I think what happened is this. Although the finish had mostly cured (I sprayed nitro about 4 weeks ago), it has been pretty warm recently (it got up to 83 today) and I had it resting on its back. Doh! So now I have to sand it flat (hope I don't sand through) & buff out again.

On to the advice: First, tell me if I'm going astray on my plan to build steaming mechanism. I plan to hook my pressure cooker to a 1/4" hose with a hose clamp and then clamping the other end of the hose to a ball-pump needle. I'll stick the needle down in the neck joint and heat up the pressure cooker till the steam until all is good.

Second, I'm planning to build a neck removal jig similar to the Stew-Mac jig. Is there something more to it than there appears?

Cheers,
Kelby
Author:  Dickey [ Fri Apr 01, 2005 5:06 pm ]
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Kelby, you may want to review www.frets.com and see how Frank sets this up.

Back to your neck, I take it you didn't have the fingerboard glued on first? By setting the neck, dry, then gluing on the fingerboard and rechecking that all is good. You should be able to avoide a too deep set neck in the future.

Matter of fact a tight fit almost precludes what you describe, but I can see how it could happen. I use the Petros method, well at least the Dickey version of the Petros method. Take a peek, two bungees hooked to the workbench and several Klemmsia's do the fingerboard extension and dovetail.





Dickey38444.0912268519
Author:  crazymanmichael [ Fri Apr 01, 2005 6:13 pm ]
Post subject: 
kelby

get a good head of steam up before you introduce needle to neck. as there is no fingerboard to keep steam in the joint space you may need to clamp something over the area with a hole it it for the needle. keep a bowl of cood water and a rag handy to mop up escaping hot water to help avoid finish damage.

michael mcclain          ;         
Author:  Kelby [ Fri Apr 01, 2005 6:30 pm ]
Post subject: 
Bruce and Michael, thank you both for your helpful replies.

Bruce, on the neck, I generally glue the neck before installing the fretboard. I suppose I picked that up from the StewMac video when I built my first flattop from a kit. I generally dry fit it first (I did this time too) and clamp the bejeebers out of it dry just to make sure it is going where it should, then take it apart and glue it up believing it will fit the same way again. I'm not sure why it set deeper during glue-up than it did when dry this time, because I clamped the heck out of it during the dry fit. I suppose it's time to try it the other way. As for Frank Ford's site, I like his set-up a lot in that it attaches to the body more simply than the Stew-Mac jig. However, the wing nut on the top seems more complicated than the Stew-Mac jig. Maybe I'll try the simplest aspects of each. I appreciate your thoughts on this all around.

Michael, thanks much for your suggestion. It should be no problem to clamp something over the space, but I would not have thought of that if you hadn't suggested it.

The positive side of all this is that I am learning quite a bit about taking necks off, and perhaps a better method of attaching the neck. (There's got to be a positive side, there's got to be a positive side . . . )
Author:  Kelby [ Fri Apr 01, 2005 6:33 pm ]
Post subject: 
One more question, Bruce, what is the function of the bungees?
Author:  Josh H [ Fri Apr 01, 2005 9:20 pm ]
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You could do like me and bolt your dovetail joint. There are a number of well known makers who do this (Laskin, de Jonge and others). It makes it really easy to disassemble should you need to in the future. You still glue the fingerboard to the top but don't use any glue in the dovetail joint.

Josh
Author:  LanceK [ Fri Apr 01, 2005 9:51 pm ]
Post subject: 
Kelby -
I had to remove a neck on one of my guitars this past summer, it was a dovetail. I didn't build a jig, I simply took two quick grip clamps and a small piece of wood. The wood went across the heel cap and the clamps pinched from the top down to the wood stick providing an upward push.
Here is a quick and dirty drawing to explain.

LanceK38444.2861111111
Author:  Matt Gage [ Fri Apr 01, 2005 10:57 pm ]
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Hey!

Now I know why Bruce has those cleats on his bench
Author:  Dickey [ Sat Apr 02, 2005 12:12 am ]
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The bungees are just there to look cool and the hooks to catch my pants and sander cords.

Nah, in case you haven't figured out the configuration. The bungees exert downward pressure, the Klemmsias exert inward pressure on the dovetail.

This way, both the x, y, and z axis of the joint are controlled. so what is the z axis? The z axis is the alignment afforded by the fretboard itself as it is clamped into position on the top of the guitar.

xyz, easy as abc. Aligning a neck is like flying an airplane. I recognized the final approach on my first neck, just like shooting touch and go's. The plane, goes up, x, pitches over, y, and it also rolls right or left, y.

They tell me that any neckset you walk away from in one piece is a good one.
Author:  Mario [ Sat Apr 02, 2005 12:47 am ]
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Kelby, what was the back laying on? If it was carpet, or some other synthetic material, you had a reaction between the plasticizers. Let it air a week or two before sanding level, or you'll maybe find it will settle some more after you levelled it.

Best to hang guitars by the neck or tail block for their first few weeks.
Author:  Kelby [ Sat Apr 02, 2005 3:17 am ]
Post subject: 
Lance, I really like your clamp method. I'll give that a shot. Simpler is always better!

Bruce, thanks for the explanation. That makes sense now.

Mario, it was resting on a moving blanket that is 35% cotton and 65% polyester. Maybe the poly interacted with the nitro. I will certainly leave them hanging from now on!
Author:  Michael Dale Payne [ Mon Apr 04, 2005 6:31 am ]
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Kelby, If the dovetail allowed the neck to set low than you must have taken a bit too much off the dovetail tendon you may need to shim. If fitted correctly the mortise will not let the tendon fit low if cam clamps are used. I would guess that a large C clamp might be able to compress the tendon enough to set it low. But even then you would have to really bear down. I under shaved my first dovetail. I went to the local RC model store and got some wing and fuselage skin. It is a very thin 3 ply Baltic Burch ply. It sands very well to almost nothing. I used epoxy to attach the ply to both sides the tendon and refitted. Worked like a charm
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