Official Luthiers Forum!

I'll just add one thing. In Ed's picture, the diagram for cutting the relief channel shows the heel cap in place. It's easier if you do all the neck fitting with the heel cap not yet on. So after you've cut the relief channels you are just left with strips on the outside edges to floss. After everything is looking good, temporarily bolt on the neck and then glue on the heel cap (after you've sanded the edge that goes up against the guitar side).

Pat

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There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

I really like Tim Allen's suggestion about backing the sandpaper with thin tape. I've torn my sanding strips, too. Thanks, Tim.

I've even used strips of regular Scotch tape and it works just fine too.

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Steve Smith
"Music is what feelings sound like"

Personally, I prefer to do it with the heel cap on, but that's just me. I just learned to do it that way, so that's how I do it.

Good point about using packing tape or masking tape as backing on the sandpaper

Good point about which direction takes off more wood when flossing. In my method, the neck is angled both side to side and front to back on the edge sander before attaching the fingerboard. Flossing occurs just to clean up the joint after paint. I always angle the neck a smidge forward during the build to account for this, since it is much much easier to bring it back than to bring it forward.

Very very very good point about making sure the sandpaper is pulled in a downwards direction. Pulling up will yield only tears of anguish...

I also used to do it with the heel cap on and whatever works for you is good. The reason I think it's easier with the heel cap not on is that with it on you must also floss under it as well as well as the sides of the heel. Otherwise a little tab develops in the middle of the heel cap that keeps the bottom of the heel away from the side of the guitar. Then, if you over floss under the heel cap that also creates a gap under the bottom of the heel. It's something you have to keep an eye on and be aware of what's happening as you floss. It definitely adds another dimension to the task. I'm not saying it can't be done that way, but having done both, I know which is easier for me.

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

This has helped me quite a bit, especially centerline issues or decreasing an overset neck. I also get things as close as I can before fitting the heel cap. To radius the cap you can stick some sandpaper to the area of the guitar it will contact and sand they radius in.

viewtopic.php?f=10101&t=42943&p=567199&hilit=Floss#p567199

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It's not what you don't know that hurts you, it's what you do know that's wrong.

These days I'm no longer pulling strips of sandpaper backed with tape. By the way the earliest use of backing sandpaper with tape on this forum that I can recall came from Colin S. He's who gave me the idea and I think/hope that I say this in my toot, attribution is important to me.

Instead I'm simply using small squares of sandpaper and working them back and forth and it works great and there is no risk of pulling upward and ruining that perfect wood-to-wood fit that we want.

Not all sandpaper is created equally either. We are liking Sait papers for anything that can tear up the paper such as fitting necks and sanding frets.

When building I do most fitting with the cap off. In the repair world if the cap stays on we work with it on, if it falls off, and they often do...., most fitting is done with it off and final fitting is done with it on.

Relief cuts are the key though otherwise one is attempting to fit the entire real estate of the cheeks which is a very long, hard slog..... Something else to look for is the transition from the tenon (or dovetail) to the cheeks. If it is not a sharp angled transition and instead has a fillet of material in there this can prevent the neck from seating snugly against the body.

Hesh lets see a pic thanks

I have not read all the posts, perhaps this has been covered -- when flossing to change the set angle the sandpaper is pulled up or down the heel, obviously the most material will be removed at the end of the stroke where the paper exits. If the angle is correct and there is a slight mis-match (gap) the paper is pulled out to the sides which will transfer the surface contour to the heel perimeter edge that has be mentioned earlier. At least this is the way I control the material removal and prevent a new problem.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Just to clarify some terminology: When you guys say "pull down", I believe you are describing the motion of pulling the paper strip down over the edge of the top or the back. Not "up", over the edge of the heel--correct? Anyway, that's what I do. I use a long strip and pull it back and forth, never allowing either tail of the strip to exit the gap. Then I slide it out sideways to check the gap. I count my strokes and give an equal number of pulls on either side of the tenon. If, during this process, I happen to get the neck cranked a bit to one side or the other, then I do a couple of corrective flosses on the appropriate side to straighten things up again. I hope that all made sense.

I recently bought this sandpaper StewMac has newly available specifically for flossing. Works great. (I like your packing tape idea though!)

http://www.stewmac.com/Luthier_Tools/To ... paper.html

Patrick you've got it. The reason why we don't pull up over the heel cap or where it eventually goes is that we all likely have discovered on our own how counter productive this can be except, of course, if one enjoys using colorful language... Personally I enjoy colorful language but I don't enjoy any lutherie task taking longer than it needs too.

Clinch buddy I don't have any pics of flossing without pulling strips but it's simply resting the surface to be flossed on the paper and then manipulating the paper back and forth while with the other hand applying just the right amount of pressure to the neck joint so that the paper can still move but the business end of the paper is removing material.

By the way this back and forth motion of the paper as opposed to pulling strips eliminates the very good point that Ken made above about the last part of the pull moving more material and at times perhaps too much.

One more thing too - invariably if you guys build em good enough to survive a while in the client's hands and I know that you do your stuff may end up in the hands of some grumpy old fart repairman (or a very pretty lady repair person). Knowing as we do that folks never bring us something when everything is honky dory.... instead they are only our friends when they need something.... when we see Luthier built instruments from an unknown to us builder the drill is different.... The estimate may be as well.

Now before anyone gets their panties in a bunch experienced repair guys know what to expect from Martin, Taylor, G*bson, and even Ov*tion but with small builder instruments there is far less trust in our experience and instead a far greater reliance on spending more time with the triage and being absolutely sure that we have identified ALL issues while the client is still present so that we can show them what we see (and get paid for fixing it as well...).

Neck joints are not the first thing that we examine but they may be the second and not to see if there is a failure but to make a value judgement, like it or not... as to if the builder knew what they were doing. A builder who can do a nice, wood-to-wood neck joint with NO filler is more likely to have decent chops with other aspects of the instrument as well. Neck joints are not easy to do very well but not impossible by any means either.

Neck joints are also something that experienced clients will look at too also for the same reasons. It's a mark of the maker in the sense that it can separate the hacks from the quality builders because of the difficulty associated with getting the joint correct.

One last thing for now - PLEASE for dovetail joint users the cheeks are not supposed to be glued to the sides........ We see a lot of this and even with some of the 70's iconic brand stuff as well. It does nothing to stabilize the joint but will very much make the eventual reset more difficult and often results in more finish repair being needed.

And really one more last thing.... for mortice and tenon, bolt-on users the beauty of the a bolt-on is the serviceability come reset time. But then we often see folks slathering on copious amounts of glue under the fretboard extension so much so that the glue can migrate into the tenon and mortice making it a partially glued tenon and mortice.

Mario P. once posted on the forum that the extension only needs a small puddle of glue in the middle of the extension and not only did I believe him but I have built this way ever since. It makes it very easy to get the extension off and I've never experienced any rattles or vibration from only using perhaps a 1" round puddle of glue under the extension.

I see one more post too so being the pedantic sort that I most certainly am.... not using strips, as we do, eliminates the need for any special sandpaper and associated costs such as shipping from Stew-Mac. And you guys thing I'm a Stew-Mac shill.....

I sand the finish to bare wood under the tongue only in a 1/4" channel around the perimeter. I lay down only a 1/16" bead around the very edge. All I'm really after is the shear strength.

Plumbers emory cloth, any decent hardware, plumbing supply, Home Depot etc.

Hesh

Sorry to keep asking questions, glueing area is something i have not really thought about as a new builder (just put on a covering of titebond then wiped away any squeeze out)
With the neck joint how much glue and where (including fretboard) please?

Hoping to get going on the neck joint redoo soon

Glue represented by black lines. Remember, a little does a lot. The joint itself does most of the work, the glue is just there to keep it in place. Just a thin 1/16" bead is ample.

No prob ever on the questions CP - that's why some of us are here.... to help!

I think IIRC you have a bolt-on and if this is the case the only thing that gets glued is the fret board extension. Place neck with fret board attached in it's final position after getting the neck angle(s) right meaning neck angle in respect to the bridge/saddle and neck angle in respect to side to side so the neck is in line with the center of the tail block. After the neck is in place I use masking tape around the fret board extension to mark where the extension covers. Remove neck and score the finish under the extension to say within 1/4" of the fret board extension edges. Lots of ways to do this by the way.

With a very sharp chisel, and this is AFTER the guitar has been finished..., remove all of the finish under the extension exposing bare wood to your score lines. After dry fitting the neck, making sure all the angles are correct, and the instrument is finished squirt about a 1" round spot of glue in the center of the area that will be covered by the extension. I like to take a single edged razor blade and scrape the bottom of the fret board extension to freshen up the gluing area as well. A few quick swipes is all it takes.

Install the neck but don't tighten the bolt(s) all the way, just snug them a bit until using a caul of sorts over the extension you also clamp the extension all the way down on the body and over the puddle of glue. Once the neck extension is down do the final tightening of the bolts. Inspect for how well it went, clean any squeeze out but you likely won't have any because of the judicious use of that little puddle of glue, and go have a pint.

I didn't go back and read the original post so if you are using a dovetail let us know?

Just reread the entire thread - it's a bolt-on, single bolt Martin Style so what I said above should serve you very well.

Thanks hesh... neck joint redone and much much better..will glue up after finishings done(got loads of questions about that!!) ..not quite as good as your neck pic but 10 times better than it was... got some beers chilling for later [SMILING FACE WITH SMILING EYES]

Good going CP!

I think that your Martin neck may be the single bolt-on, glued mortice and tenon style that Martin uses on some of the lower-end stuff, 16's, 15's etc.

The joint is originally glued at Martin meaning they glue the mortice and tenon and the bolt, the single bolt is only there to hold everything in place until the glue dries.

Now I did not advise you to glue the mortice and tenon even though Martin does and here's why: The glued mortice and tenon often does not stay glued and we have repaired many of these instruments as a result. Even when they come in for simple set-ups the neck angle can be changing because the glue is in sheer with this style of joint and can fail and at times does. The single bolt is hidden by a wood plate on the Martins that is held on with double stick tape.

It's often the case when the glue joint fails that repair folks will either simply remove the plate and crank the bolt restoring the factory set neck angle or some remove the neck and reinstall with glue. Others may convert to a two bolt, bolt-on system which IMO is the best way forward but would void any warranty in that we are reengineering the instrument.

Anyway you are fine with what you did in not gluing the tenon and mortice because it will likely give in time anyway. Be prepared though that if you see the gap at the heel or an expanding gap to remove the wooden plate (if the kit came with one) and simply crank the bolt. Doing this with bi annual string changes could be all that you need to do.

I didn't tell you to glue the mortice because I don't agree that this joint works well and the glue often will not hold over time anyway. You could if you want to glue the mortice and tenon taking care to not get glue squeeze out on the cheeks but this will only make things more difficult when the glue joint fails as they often seem to do.

Nice going CP and glad to hear that you are satisfied with the joint now. Neck joints are perhaps the single most difficult part of one's first guitar and the neck angle is so very critical to how well the instrument plays that this is where no corners can be cut. Since you are though this part the rest should be easy for ya and more fun too!