Rookie kit builder in Atlanta area needs help

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johnnparchem
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Re: Rookie kit builder in Atlanta area needs help

Post by johnnparchem »

Danl8 wrote:Have you chalked the joint to see where you are getting contact?
Yes chalk to see where you are and are not hitting. Also in two pictures I it appears you do not have enough relief right where the tenon comes out out the heal. I see it in the close up of the tenon and I see the top down view. Clear out the area so the neck is not hanging up.
David Mathis
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Re: Rookie kit builder in Atlanta area needs help

Post by David Mathis »

Thanks Danl8 and John. I will chalk the joint and increase the relief around the tenon and report back.
Diane Kauffmds
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Re: Rookie kit builder in Atlanta area needs help

Post by Diane Kauffmds »

David, check to see if it's bottoming out by sliding a thin 6" ruler, or something under the dovetail. You'll know if you're bottoming out.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
Diane Kauffmds
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Re: Rookie kit builder in Atlanta area needs help

Post by Diane Kauffmds »

I'm looking at the last photo. Is the neck twisted a bit to the right As you sight down the neck? As I look at the photo, I can see the shadow from the right side of the dovetail, on the top. It looks to me like the right side of the dovetail isn't quite in the pocket.

If so, making a small correction for this will tighten up the dovetail.

In the end, if the neck is centered on the guitar body, if it's square onto the body and not twisted, and it's angled back so that a long straight edgedge or ruler on edge, just graces the top of the bridge, when it's laying on frets, then you need to glue some thin pieces of wood on each side of the dovetail to tighten up the joint.

Also, a couple of members and John Hall suggested setting the neck after the fretboard is attached. Sure enough, it's been easier for me to set the neck with the fretboard attached. It's a lot easier to see problems in any of the 3 dimensions with it attached.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
David Mathis
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Re: Rookie kit builder in Atlanta area needs help

Post by David Mathis »

I increased the relief in the area where the tenon comes out of the heel. There was a marked improvement with that step. Then I chalked the mortise and slid the tenon into it. The attached images of the tenon show the small areas where the joint is contacting.
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Danl8
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Re: Rookie kit builder in Atlanta area needs help

Post by Danl8 »

That would be very little contact surface. It might be time for shims (ok to shim -- even Martin does that). Ordinarily if the neck was still standing above full seating, the chalked area would be chiseled or sanded off. Reseating and rechalking, the next pattern would be chiseled off repeated again and eventually the neck would continue to drop and be seated fully in the mortise. All the while checking angle and centerline.
David Mathis
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Re: Rookie kit builder in Atlanta area needs help

Post by David Mathis »

Okay, shims it is. As you can probably tell from the images, I already did shims once – and I used thin strips of mahogany. I assume that's the way to do it. Also, since the chalk area was so thin, it looks like I sanded the tenon angle a bit too steep so that only the very edge was contacting the mortise. Does that sound right?

Thanks!
johnnparchem
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Re: Rookie kit builder in Atlanta area needs help

Post by johnnparchem »

David Mathis wrote:Okay, shims it is. As you can probably tell from the images, I already did shims once – and I used thin strips of mahogany. I assume that's the way to do it. Also, since the chalk area was so thin, it looks like I sanded the tenon angle a bit too steep so that only the very edge was contacting the mortise. Does that sound right?

Thanks!
Sounds right. I personally can not use sand paper to make flat surfaces. I always end up with curves so I use sharp chisels instead. Other have success with sanding blocks cut with the dovetail angle. If you are constantly checking you will avoid going to steep.

You were not so far off with the line of chalk I see. It it was twice that I would accept it. It went the whole length of the tenon which was good.
Danl8
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Re: Rookie kit builder in Atlanta area needs help

Post by Danl8 »

Ideally there should be an even chalk print along the entire tenon surface, both sides, showing the tenon is fully and evenly engaged with the mortise bearing surfaces. At the same time the heel cheeks should be tight against the sides.

One of the mistakes I eventually fixed in what I was doing was to get the sides in the mortise area perfectly flat before trying to seat the neck -- that made fitting so much easier, and also relieving the edges of the mortise which can hold off a good mating. The other aha was taking so very little off the tenon, not too much which was easy to do. The center line alignment is managed by very small relief on the cheeks. It also helped to watch John's videos over and over. For me both sanding and chisels can be a challenge to get straight cuts, if I'm not really careful. I use a hardwood stick with the long edges cut to the angle of the cheek-to-tenon and 1/2" tape sandpaper glued on. That really minimizes any rounding risk.
David Mathis
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Location: Atlanta

Re: Rookie kit builder in Atlanta area needs help

Post by David Mathis »

Diane Kauffmds wrote:I'm looking at the last photo. Is the neck twisted a bit to the right As you sight down the neck? As I look at the photo, I can see the shadow from the right side of the dovetail, on the top...

Also, a couple of members and John Hall suggested setting the neck after the fretboard is attached. Sure enough, it's been easier for me to set the neck with the fretboard attached. It's a lot easier to see problems in any of the 3 dimensions with it attached.

Diane, thanks for your input. In the photo you reference, the neck is very loose because the tenon would not seat into the mortise and I couldn't hold it in place while photographing.

That sounds like great advice to attach the fretboard before setting the neck. Do you normally install the frets before gluing the fretboard to the neck?
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