Acoustic Guitar Construction

That's a good point. Rusty have you tried SM for assistance with their product?

deadedith wrote:That's a good point. Rusty have you tried SM for assistance with their product?

Yes, I did talk to them via email. To be honest I'm as wise now as I was then but I fully appreciate its a difficult thing to advise someone by viewing pics etc . The last guy here had the exact same problem as myself. My downfall is that i carried on strip sanding at the heel and hoping I would eventually get the neck angle correct. So, heres the update,
I now more or less have the neck angle close to being right--the straight edge is just about clearing the bridge --before this it was hitting the bottom of the bridge. But what i failed to notice was that the joint was also getting looser and looser !@!@!^
Theres No bite at all when i push it tight.
So now all I can think of is how to shim the joint or with what do I shim it ? How much glue do I use to fill the space ?
Will my neck be as stable as it should be with all the shims that I will probably need to use now etc etc

Theres one thing for sure , I will never buy a Dovetail neck again as this has really put a downer on my guitar building intentions. But I will not give in !!

Oh man, I feel for ya. I've not done a dovetail, never will, so I cannot really advise you on it.
But really, do not give up. Get a kit from Ken and you will be smiling and happy, your skin will clear up, no more halitosis (not saying you have any :-)), the ladies will notice you even more, and an archangel may even drop by to say howdy.. Ok, the angel was over the top, but I just want to encourage you so that once you get the good kit, and have a success under your belt, there will be no stopping you.

Don't take this wrong - saying this "I now more or less have the neck angle close to being right" does not make me comfortable that you are fully aware of the goal -- which is to get the angle perfect and to do that you must understand the "straight-line" concept mentioned in the articles referred to above. So be aware that .5 degree error can shoot your finger-board plain way over the top of the saddle.

Anyway, shim stock needs to be wood veneer, don't use paper or card stock etc. Proceed by using layers of cellophane (Scotch) tape to make a master gage for each side of the tenon, add layers of tape and test the joint is snug and at the correct center. With the neck completely seated in the mortise check your angle and the fit to the body. Once satisfied -- tap the neck out peel off the tape measure the thickness with a micrometer or caliper fabricate a veneer shim just slightly thicker and glue (Titebond, Elmer's etc.) that in place to the tenon. I assume you have made an 80 degree sanding block? The shimmed tenon should require a bit of sanding on each side of the tenon to get it to back to be the same as the test fit. Shimming does not impact the integrity of the guitar.

deadedith wrote:Oh man, I feel for ya. I've not done a dovetail, never will, so I cannot really advise you on it.
But really, do not give up. Get a kit from Ken and you will be smiling and happy, your skin will clear up, no more halitosis (not saying you have any :-)), the ladies will notice you even more, and an archangel may even drop by to say howdy.. Ok, the angel was over the top, but I just want to encourage you so that once you get the good kit, and have a success under your belt, there will be no stopping you.

Thanks Dave, you put me on to Ken some time ago and i have purchased a few of his brilliant jigs--hope to get more as well.

I',m beginning to think I'm a lost cause here to be honest with this kit. I will try post a pic here to show where I'm at but its not looking good and i think I have sanded off more than I should have from the tenon--the joint is loose as hell !!

Thanks for the pep talk anyway but so far no archangel......


tried loading pic but wont accept it -sorry

Update on my stewmac kit fiasco
My neck joint is way too loose and i obviously ended up sanding too much material from the tenon so theres nothing I can do about that now but Ken has mentioned a way to shim it. But what about the gap between the heel and the sides or can that be shimmed as well ? I have to pull the neck back that far to get the neck angle right and there seems to be no other way do do that now but it leaves a gap of over 1/16th at the sides and also under the fingerboard extension

Thanks for all the help so far and all suggestions most welcome .
Rusty

This is not an unusual condition but the ultimate fix is way too involved to explain in forum posts --in my view tidbits of opinions will only make your situation worse!!! Every fit situation is unique to the guitar needing the changes. This is a math problem. My best advice is for you to get Bill Cory's book

viewtopic.php?f=29&t=35

Its has the best explanation of dove tail tenon sanding cause and affect -- in your situation you need to sand a new angle on the heel cheeks leaving the top alone and removing material starting at the bottom --- Bill's book gives a good idea (math formulas) of how much has to be removed etc. Then you have to shim the tenon as I described earlier. Your focus has to be getting the heel cheek and finger-board plane to the correct angles the fact that the tenon is loose means nothing at the point -- that can be easily corrected by adding shims once the neck angle is set. Doing anything prior to when you completely understand the goal will not yield good results.