Dovetail joint fit need help with correction

Dove Tail -- Mortise and Tenon -- the right choice and how to get it to fit
Beau J
Posts: 28
Joined: Fri Apr 26, 2013 9:02 pm
Location: Cedar Park Texas

Re: Dovetail joint fit need help with correction

Post by Beau J » Tue Apr 30, 2013 12:43 am

The body is 91.8 and the neck is 88.7
Beau

Tim Benware
Posts: 1489
Joined: Thu Dec 22, 2011 1:22 pm
Location: Asheboro, NC

Re: Dovetail joint fit need help with correction

Post by Tim Benware » Tue Apr 30, 2013 9:52 am

Beau J wrote:The body is 91.8 and the neck is 88.7
91.8 + 88.7 = 180.5. You are 0.5 off. This is like starting off needing a neck reset. I think Ken has a tutorial on how to sand the top down and feather in the sides to achieve the 91.3* angle you need for the top or you can floss the heels to achieve a 88.2* on the neck. I use "ACE" to get there that is:

A = neck angle
C = Center line
E = Elevation

Get the angle on your neck first, get the proper center line, then lower the tenon into the mortise. You may find when you get close you'll need to use shims to get a tight fit because the angle is so far off. I'm not sure how much the top would need to be sanded for the other method or if a combination approach is appropriate.
I've "Ben-Had" again!
Tim Benware
Creedmoor, NC

ken cierp
Posts: 3924
Joined: Tue Dec 13, 2011 11:23 pm

Re: Dovetail joint fit need help with correction

Post by ken cierp » Tue Apr 30, 2013 10:17 am

Tim --- Beau

In this case sanding anything off the sound board will make matters worse. The level across the sound board/neck plane indicates that the neck is tipped upward leaning toward the sound board. This as Tim mentioned is indeed a repair operation. The key at this point is to get the heel cheeks shaved (bottom up) so the neck tilts back until the level lays flat along the full length The Straight Line -- you cannot be concerned at this phase as to how the dove tail fits it certainly will be very loose. Once you have the straight line and the neck aimed on center, you can go about the business of shimming the dove tail tenon and or mortise to make it tight. The two others guys that were posting their problem I suspect failed to grasp this requirement and I believe it lend to some long term grief.

Again, I have not seen or read a better dove tail joint shimming/sanding procedure than that found in Bill Cory's book.

Since your angle is a little steep some adjustment in bridge thickness and saddle height may be necessary but that is not a big deal and frankly is often over looked and not taken into consideration as one of the controlable neck set variables.

rusty999
Posts: 80
Joined: Mon May 28, 2012 1:36 pm
Location: Ireland

Re: Dovetail joint fit need help with correction

Post by rusty999 » Tue Apr 30, 2013 10:33 am

""The two others guys that that were posting their problem failed to grasp this requirement ""


I may have been one of the two other guys but I now have one of the nicest sounding guitars ever build in my opinion LOL

I did have the same problems but got great advise on the forums and stuck with it until I overcame them.

Dont give Up !!

ken cierp
Posts: 3924
Joined: Tue Dec 13, 2011 11:23 pm

Re: Dovetail joint fit need help with correction

Post by ken cierp » Tue Apr 30, 2013 10:40 am

Rusty -- Good to hear it worked out for you, how's the action/playabilty on that guitar?

rusty999
Posts: 80
Joined: Mon May 28, 2012 1:36 pm
Location: Ireland

Re: Dovetail joint fit need help with correction

Post by rusty999 » Tue Apr 30, 2013 10:53 am

kencierp wrote:Rusty -- Good to hear it worked out for you, how's the action/playabilty on that guitar?

All Good Ken, I know it was a nightmare at the time and I was close to packing it in but it was definitely worth it. I gave it to my son as a Xmas present and believe me he would have told me long ago if it was not right as he is a good guitarist himself. No complaints so far.

Thanks again for all the advise---looking forward to my mega mold arriving someday soon and then things will really start to fly around here !!


Regards from Ireland
Rusty


{ Kevin }

Tim Benware
Posts: 1489
Joined: Thu Dec 22, 2011 1:22 pm
Location: Asheboro, NC

Re: Dovetail joint fit need help with correction

Post by Tim Benware » Tue Apr 30, 2013 3:50 pm

kencierp wrote:Tim --- Beau

In this case sanding anything off the sound board will make matters worse. Good to know, I haven't tried it that way so wasn't totally sure if it was an option.

Since your angle is a little steep some adjustment in bridge thickness and saddle height may be necessary but that is not a big deal and frankly is often over looked and not taken into consideration as one of the controlable neck set variables. - I have gotten so I now make the bridge last and custom fit it to the exact height I want once the neck is glued on to account for the perfect thickness.
I've "Ben-Had" again!
Tim Benware
Creedmoor, NC

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