Official Luthiers Forum!

I understand the grain of the end (neck) block is to be horizontal to be the same as the grain of the sides,but does the end grain,which is quartered sawn, to go up & down(vertiacally) or side to side (horizontal)?? I bought a 4x3x30 sapele to make to necks and I thinks I can make several neck blocks.
Clinton

crich; you re actually better off with a laminated end block !
Or if you useing solid wood the grain shoud be horizontal -this will help to keep cracks from spreading and be strong in every direction .
PLus be less prone to swelling from humidty in the wrong direction!
mike

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Mike Collins

Or do as I do and use a three piece neck block horizontal grain on the centre section and grain running for and aft on the foot and top.

This ones in Cherry.

Colin

Colin S38961.6594907407

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Colin-How do I use the user uploads?
Mike-you use a laminated block to accept your tenon on your neck? I think I understand the advantages of the laminations.I'm going to have to investigate this further. Clinton

Colins block is perfect!
I'am going to a bolt on system -BUT with a laminated block for strength .
Mike

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Mike Collins

Hey, when I refreshed the page the image came through. I like that! I appreciate the wisdom on the end grains. Ain't this place cool. Clinton

Michael, This is block is also for a fully bolt on neck, so a channel will get routed in the top section for the neck extension to fit. The neck is also in cherry, I like to use the same wood in the neck block as in the neck as I feel that when bolted up they become a single unit.

I've used this style on about a dozen guitars or so.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

[QUOTE=Colin S] Or do as I do and use a three piece neck block horizontal grain on the centre section and grain running for and aft on the foot and top.

This ones in Cherry.

Colin

[/QUOTE]

Colin - It looks like you have long- and short-grain surfaces glued together. Do you ever have any problems with this with changes in humidity?

If you did have a change in moisture content in the wood (for example an increase in moisture content) , the top and bottom pieces would expand laterally, and the center piece would not. It seems to me that you would either get creep in the glueline, or failure of the glue joint.

In the top and back of a guitar this situation exists also ( at either end) , but in that case the top and back are thin enough to allow some deformation (in the same way that plywood is glued together long- to short-grain and survives). Here, the pieces look very solid.

Obviously this works for you, but I'm surprised you don't run into problems.

Phil

Colin, I've been thinking about trying an all bolt neck joint as well. Do you radius the sides for your tops? I use a 30' dish for my tops but don't radius the upper braces. I'm concerned that if the extra extension on the heelblock is radiused I'll have trouble getting the fingerboard to lay flat on the top.

Any thoughts?

Thanks,

Bob K

Some classical builders have grain running horizontal as it makes for better glue joint. One builder uses 3 piece heel blocks with horizonatly oriented end pieces and a verctial grain centre piece.

I use vertical grained heel block and a laminated marine ply end block.

I think that the most interesting thing here is that it seems as though anything works--grain parallel to the sides; grain perpendicular to the sides; plywood; or a hybrid of any of the above.

[QUOTE=Phil Marino] Colin - It looks like you have long- and short-grain surfaces glued together. Do you ever have any problems with this with changes in humidity?

Phil

[/QUOTE]
Phil,

What would be your estimation of the integrity of the glue joint over time if the top and bottom piece in the assembly were flat sawn? I'm asking because I use the same neck block design as Colin. Joe Beaver38962.6271527778

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Joe Beaver
Maker of Sawdust

Phil, never been a problem, these are relatively thick pieces of wood so any change in their moisture content is very slow. I've made 25 or so with this format, and not a problem in any one. I know quite a number of builders who do this and have never heard of a failure.

If you move it from winter Canada to summer Florida there might be a problem, but you'd have all the braces pop of long before this joint gives a problem.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

I agree with Carlton here, laminated heelblocks are strong by definition and so are the plywood ones even if lighter in weight IMVHO, i think that as soon as there is glue involved, the strength is added already, we only have a matter of choice regarding the types of wood to use..

What about issues with chip out when routing mortises?

[QUOTE=Joe Beaver] [QUOTE=Phil Marino] Colin - It looks like you have long- and short-grain surfaces glued together. Do you ever have any problems with this with changes in humidity?

Phil

[/QUOTE]
Phil,

What would be your estimation of the integrity of the glue joint over time if the top and bottom piece in the assembly were flat sawn? I'm asking because I use the same neck block design as Colin. [/QUOTE]

Joe-

Most woods expand and contract 1 1/2 to twice as much (with changing moisture content) parallel to the growth rings (flatsawn) than right angle to the rings (quartersawn).

That's one of the reasons tops and backs are usually quartersawn - for dimensional stability. The mechanical properties (stiffness and strength) are pretty much the same either way.

So, the more stable quartersawn orientation - for the top and bottom pieces of this glued-up neck block - would result in less glue line (and wood) stress if there were a change in moisture content, compared to flatsawn top and bottom pieces.

But, as Colin said, if there's not much humidity change, it won't be a problem either way.

Phil