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I am having difficulty with a gap on the treble side of the neck/heel joint. i have had to do a bit of flossing on the bass side to get the neck to line up with the center line, it subsequently looks very good, but the more I take the bass side down, the more there is a gap on the treble side. When I get the neck aligned I use a technique I learned from Frank Finocchio where I put a piece of double stick tape on both sides of the mortise on the body and push the heel back and forth on the sandpaper to take them down equally

Any suggestions?

Thanks
Richard

What type of Neck joint?

Bolt-on

hello im not fimiliar with frank finocchinos method but
did you take a look at john halls videos ..

blues creek guitars dovetail neck setting
its very through

its the best neck set video ive seen on the web

tomas

Did you sufficiently relieve the face of the heel contacting the body?

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"Building guitars looks hard, but it's actually much harder than it looks." Tom Buck

More than likely, the problem is that the side of the guitar at the heel joint area is not flat.
To check it, lay a straight edge along the path where the edge of your heel lays & see if there are any gaps. If you can rock the straight edge, even a little bit, it'll really screw you up.
I had this problem on my first parlour guitar. I sanded & sanded & drove myself half nuts trying to get it right. Finally, I sanded the sides with a 3" X 6" flat plywood sanding block & tried again.
Took about 20 minutes to get everything fitting nice & tight.
Instead of laying sandpaper down both sides of the mortise, try covering the whole area & then cut away the paper over the mortise. Take short strokes, so the bottom of the heel gets sanded evenly with the rest.
Oh yeah... I know this seems silly, but... Make sure the tenon is not bottoming out on the bottom of the mortise. I like at least 1/16" clearance.
Good luck! I know how frustrating this step can be.

Also, make sure you're not pulling up on the paper. DAMHIKT.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

Richard,

As Daniel points out -- if the sides of the guitar are not exactly flat -- sliding the neck up and down across the body could further hollow out a low spot and make a gap....

I might first try some chalk or sanding dust all over the inside of that neck heel/body joint to see where it is hitting... Could be just not enough clearance at the neck tenon where it meets the heel.... or not enough undercut on the heel itself.... The dust will tell you.... A thin 0.002" feeler gage is also super handy here -- you can stick it in and feel where it hits....

Do you remember the way that John Hall showed us how he flosses the neck joint at the SC get together? You carefully cut a thin piece of sandpaper and fit it between the neck and body with the grit facing the neck. Then, slowly pull it out from the bottom of the neck heel.... you can lightly snug up the neck with the neck bolts as you go....

I have done it this way now several times -- I use 80 grit sandpaper to start with.... The advantage is that if the side is not perfectly flat - flossing that joint will still make a nice tight joint.... it will shape the heel to conform to the body.

Just gotta be careful that none of the grit makes marks outside the neck joint where they are visible.....

Thanks

John

One other thing that's caught me up once or twice. Not sure if it's painted or not but if it is make sure there are no ridges around the mortise. It can lift the paper and have it not be true to the sides.

The bass side of the tenon is against the side of the mortise.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

I decided I oversimplified my response

And I will restate. Keep the butt and neck blocks vertical. Use side spreaders and block spreaders to keep then as close to vertical as possible. Vertical to what? The top is a good reference.

This happened to me the other day - it took me a few minutes to figure out that the tenon had bottomed out in the mortise.

As the others have said, there are a couple things you need to do to achieve a tight fit

1) Chisel a relief around the heel. You only need about 1/8" neck surface touching the body. This makes it faster to remove material and get a good fit quickly.

2) The headblock area needs to be perfectly flat from the top to the back. I find it essential to use flat sanding blocks with different grits attached.


Best of Luck!!!

If you stop and think about it, you can end up with butt and neck blocks that are not parallel to each other. If you think about how this affects the nature of the joint surface at the neck block, all kinds of issues become apparent. I have been through this and I pay a lot of attention to getting these blocks parallel.

As afar as I am concerned, the neck/tail block interaction has nothing to do with fitting a neck .. a friend of mine builds more avante garde styled guitars, think wierd potato shape .. the blocks are both at wierd angles, and have nothing to do with each other. What is important is to have the mating surface flat from top to back - not side to side, unless you have flat shouldered shape. All my guitars have curved (side to side) shapes in the neck joint area, because I hate the flat look 9and as the guitar starts to fold up, it will look like its collapsed inwards - yechhh) ... and the neck can be made to fit fairly easily.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I thinks things got turned around I am talking about the neck block/heel not neck block and tail block

It looks like it is a combination of a slight hollow in the sides and I rolled the edge of the heel a little, But its not bottoming out there is about .080" of room. There is a bit of play in the mortise and tenon joint should that be shimmed to tighten it up?

Let me make sure I understand the relationship. Mike you said the heel cheeks need to be parallel, that makes sense however one side may be slightly lower than the other, this would correct for the centerline alignment right?

The joint should be loose so the neck can respond when you try to change the neck angle. If the joint is tight, no amount of flossing will have any effect.

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"Building guitars looks hard, but it's actually much harder than it looks." Tom Buck

makes sense

I do necks mostly like that. It works best for me if the side, where the neck meets it, is perfectly flat from top to back. I sand it flat if it isn't. It also works best for me to do the joint sand by pulling the neck in only one direction. I tend to rock a curve into it if I go back and forth.