neck block for flush-fitted bolt-on neck

[peter havriluk]

The idea of a 'neck block' is a given for those necks who use dovetails or a mortise/tenon tongue and receiver arrangement. But what is structurally necessary when the neck will be bolted flush to the front of the guitar body? No dovetail, no tongue. I think I'm asking about what needs to be considered when a neck block is replaced by a hunk of 3/4" plywood, for the sake of conversation. Maybe thinner ply would suffice? Anything else need attention, and any idea of how much attention?

Many thanks.

[ken cierp]

I would not underestimate the structural importance of the top and back glue surface of the neck block. These wide areas tie the sides to the back and sound board helping to resist tipping. Martin and others have even added a cantilevered tongue that runs out to the shoulder brace. Classical makers go a step further and have the long Spanish foot extension on the back of the neck block.

[John Parchem]

I agree with Ken. The heel block size is not just to support the size of a tenon. As Ken said the joint with the top and the back keeps the guitar from folding. Assuming you will have a block under the top to support bolting on the neck, You will also need a structurally sound heel block supported by the back and the rims to support that block.

[peter havriluk]

Thanks for the comments. A bit of background to a practice goes a long way to making sense of the technique being wondered about.