Neck Setting

wblock77 · #1 03-11-2023, 01:42 AM

Doing a fair amount of work on this guitar. Replaced bridge, fixed lots of cracks, replaced binding, replaced a fair amount of broken kerf lining, reglued a couple braces. Pulled the top to do this. The neck came of very clean with no tear out and very little glue to clean up. All put back together and everything seemed to fall in place well. Ready to set the neck (it needs a neck reset as the fretboard points into the middle of the bridge). I decided to dry fit it back in to make sure I was still where I was before taking anything apart. I am, still points to the center of the new bridge. The joint feels good as if it is wedging in. Goes down until the fb extension is contacting the body. I noticed that the heel comes up short from where it initially was (see pic). I clamped it as if gluing and this didn't help. Position is being held by the extension and presumably, the mortise joint. I had to work the neck to get it to come back out. The extra space does not bother me but I don't want to proceed with shaving the neck until I understand this. Your thoughts are appreciated. I know it is tough to evaluate without it in front of you. I've checked everything I can think of; new binding is clear of the joint, top is flat down on the kerfing (which was not replaced at the neck area).

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CowhornShoehorn · #2 03-13-2023, 02:01 PM

My initial thought is the wood on the joint surfaces expanded due to the heat and moisture used in removing the neck. Even after drying, the mating surfaces of the joint would no longer match and would need to be cleaned up. This is not unusual. As you noted it is hard to say without being there first hand and the work you did could change the body geometry at the neck joint, but if there isn't anything obvious I think you proceede with cleaning up the joint, adjusting the angle and fitting it as you would any other repair.

JonWint · #3 03-13-2023, 02:38 PM

Clean the dovetail contact surfaces of glue residue and rough wood with file/sandpaper. The second photo shows a gap between the binding and bottom of fretboard equal to the heel shortfall.

I use a mini bar clamp and put some force on it. What clamp are you using?

wblock77 · #4 03-13-2023, 07:40 PM

I took a straightedge and ran it along the top looking for an airgap (like you would when checking frets). When my steel ruler got closer to the dovetail opening, I stared to see some daylight as it ramped up a bit there. I think that would be in keeping with joint swelling due to steaming idea. I had the binding level with the adjacent top. I have the joint squeaky clean now and still no help. Here is the clamp I used but not a picture of when I squeezed the joint. I ordered some carbon paper to see what is going on in the joint.
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CowhornShoehorn · #5 03-14-2023, 10:56 PM

Swelling and distortion from steaming primarly affects the gluing surfaces. Cleaning and sanding those surfaces so they again match, as well as cleaning - removing glue, gunk, crud (some techincal terms there) from the underside of the FB extension and the top of the tenon under the FB extension.

From your pics, and as mentioned by JonWint, the gap between the fingerboard extension and the top at the edge of the body appears to be about the same as the shortfall at the heel cap. It’s probably a matter of cleaning up the joint and getting the tenon to set all the way down into the mortise. Carry on with the carbon paper!

wblock77 · #6 03-17-2023, 06:53 PM

I used carbon paper and the joints seem to be sliding together nice and even. I thought I would try to chisel out the dish around the tenon to get ready for do the sandpaper pull thing on the neck. I gotta tell you, that wood is hard as a rock and my chisels are just not sharp enough. I then decided to just go the sandpaper pull route knowing it would take many pulls with all the wood in place. I used 120 grit and those pulls got me nowhere. Dropped down to 80 grit and making a little headway now but ran out of 80 grit. Ordered some more. The funny thing is, as I made my 80 grit pulls, the the neck seated properly and goes all the way down to where it originally was. The sanded area does not get glued and looked clean from the start. Maybe a week of extra drying the joint is what did it.

CowhornShoehorn · #7 03-19-2023, 12:05 AM

Excellent. It sounds like you're getting the desired result. Flossing the cheeks will allow the dovetail tenon to set deeper in the mortise and am guessing that facilitated the alignment - though don't want to discount the benefit of completely dry wood

The flossing with the fingerboard in place will also tilt the neck angle back, improving the neck alignment... though probably not enough to correct a neck angle that aligns to the middle of the bridge as you described initially.

wblock77 · #8 03-19-2023, 05:30 PM

I admit, I had to Google "flossing the checks". Thanks for helping to educate me. I love to learn this stuff. The shaping is going very well. As I mentioned, my chisels weren't up to the task of creating a dish near the tenon so I've been pulling away. It is going slow but well. My old hands need rest between pull sessions. I check often and my angle is almost to the top of the bridge. The neck meets the body very flush with little to no rounding at the outside heel edges from not pulling down away from the neck. All in all, I am feeling fortunate so far. Can't wait to get this finished and glued up. I ordered some maple shim materiel to put under the extension, but I don't think there will be much gap. I'd rather not remove frets and level a hump out of the fretboard. If I don't see sandpaper for a while, that would be fine with me. I really do appreciate all the great advice you guys have given me and kept me out of trouble.

Fathand · #9 03-19-2023, 09:27 PM

Quote:

Originally Posted by wblock77

I admit, I had to Google "flossing the checks". Thanks for helping to educate me. I love to learn this stuff. The shaping is going very well. As I mentioned, my chisels weren't up to the task of creating a dish near the tenon so I've been pulling away. It is going slow but well. My old hands need rest between pull sessions. I check often and my angle is almost to the top of the bridge. The neck meets the body very flush with little to no rounding at the outside heel edges from not pulling down away from the neck. All in all, I am feeling fortunate so far. Can't wait to get this finished and glued up. I ordered some maple shim materiel to put under the extension, but I don't think there will be much gap. I'd rather not remove frets and level a hump out of the fretboard. If I don't see sandpaper for a while, that would be fine with me. I really do appreciate all the great advice you guys have given me and kept me out of trouble.

If needed, I "create the dish" with a dremel using a bit like the one in the 11 or 2 o'clock position.

Shim material, I make from scraps, usually from fretboard leftovers or from some veneer.

I don't enjoy the flossing process either.

CowhornShoehorn · #10 03-19-2023, 11:20 PM

Thanks for that reminder Fathand. I too have pulled out the dremel to dish the tenon - especially on maple.

As flossing continues and the neck angle drops back, the bottom of the tenon is going to sit deeper in the mortise, causing the fit at the heel to start getting sloppy. The more material that is removed from the cheeks, the sloppier it's going to get. This is normal with neck resets and a very thin shim is placed in the bottom of the dovetail joint to tighten it all up again. A piece of 10 thousands veneer will probably be more than enough. If it's too much, you can try only placing the shim on one side or the other of the tenon - depending on what gives the best fit. Once the shim is glued to the tenon, some fitting may again be necessary to get it all to line up and be tight before finally gluing the neck back to the body.

wblock77 · #11 03-20-2023, 03:45 AM

Thank you. I thought about using the dremel but sometimes they get away from me. I knew it wasn't likely but figured I'd just play it safe and muscle through it. Next time, dremel for sure. I finished the pulling and it levels just above the bridge now just where I want it. My shim materiel gets here today and I will thin a piece down for the tenon. I can feel the sloppiness you are talking about but not too terrible. Elderly has a nice video addressing this shimming process and I just watched it. More fun awaits for me this afternoon. Think I'll spend my morning making a caul for clamping the neck down over the frets.

CowhornShoehorn · #12 03-20-2023, 11:00 PM

Looks like you have everything you need to bring this home. Enjoy!

Fathand · #13 03-21-2023, 07:31 AM

Quote:

Originally Posted by wblock77

Thank you. I thought about using the dremel but sometimes they get away from me. I knew it wasn't likely but figured I'd just play it safe and muscle through it. Next time, dremel for sure.

When I carve with a dremel and one of those agressive bits, I hold it in my right fist, bit pointing left, like a water ski rope handle. I apply the bit lightly to the wood and pull towards me by flexing fingers and wrist. I have good control this way. Hope that makes sense.

wblock77 · #14 03-22-2023, 11:13 PM

Thank you all again for the input and advice. I can't express how grateful I am. Two regrets in this restore. I wish I would have made the bridge plate smaller as advised but I already had it glued in. Also, I probably should have installed the bridge after the neck was set as advised. I'm in a bit of a stall as I can't seem to get my fret board extension shim tapered with the modest hand tools I have. I think I am going to buy a tabletop disk/belt sander this week to expedite that process. No more pulls for me. Here is a video link of the major items I have done to it. No mention of the cosmetics but I have been dabbling at that too. More of that will come after I get it back on its feet. This is labeled Part 2. There is a part 1 on my channel but it is mostly me whining about all the work I have to do. I'm also considering painting the side of the binding black to look more like the original. I found some 50 year old new old stock in a Chicago warehouse that was the right size and color matched the perf that I left on there

https://youtu.be/j3gF5JdXztI

Bill

Fathand · #15 03-23-2023, 06:54 AM

I bought a used belt/ disc sander for $50. I use it to make shims , and lots of things. I start with a larger than needed piece of wood. Put a taper on it that looks close, see where it fits then cut to length. You can also double side tape your shim to a piece of scrap to give yourself something to hold onto.