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I am considering changing my design (dimensions, style, material, etc.) for the neck block and tail block. I want to know what you are doing and what your thinking is as to why you are doing it. But before I ask the questions, I will tell you what I am doing.

I have a bolt on neck so neck bolts go thru the neck block and bell washers bear on the neck block. The tail block ends up eventually with with one hole in it for either an end pin or a pickup's end pin jack.

Previously I have used mahogany for the neck block, sized like Martin's. However, I cut the block completely through and insert a harder wood (like zebra wood, rosewood, maple) so that the washers bear on a much harder surface than mahogany to resist compressing the wood and thereby loosening the bolts over time. This creates a 3 part laminate block with mahogany, hard wood, and mahogany. I 180 degrees rotate and reverse the grains of the mahogany pieces after cutting so they do not line up, yet all 3 pieces present only side grain (no end grain) for gluing to the rims, top and back. I (like Martin) have no extension on the top or bottom of the neck block to further strengthen the top or back to stop/minimize future rotation of the block/neck.

My finished tail block is mahogany and about 0.6" thick. I glue two pieces together 0.3" thick each. The outside piece has its side grain presented to the rims, top and back. The remaining inside piece, which does not glue to anything but the outside piece (its top and bottom are tapered way from the top and back) has its grain rotated 90 degrees to the outside piece so the lamination is very strong since no grain runs through the tail block.

1. Many builders use plywood for the tail block. (And I don't see anything wrong with this.) If you do this, why not use it for the neck block too? What is your thinking?

2. Many builders are adding extensions to the neck block. Some just for extra strength to stop rotation. Some to provide material for a completely bolted on neck including the fretboard extension over the top of the guitar. What are you doing and why?

I look forward to your input.

1. Tail block, Mahogany, 10mm, grain direction same as sides, glued to 6mm birch ply to help prevent splits from shocks to endpin/jack. Tried similar recently for neck block - didn't like the aesthetics, it's clearly visible through the soundhole/soundports.

2. I add an extension to the neck block, wedged against UTB and angled to the grain of the soundboard, with bolt on M & T joint

a) To help with rotation
b) To "couple" the body to the neck sonically
c) Notes fretted above the neck block area sound fuller (more mass under the frets?)
d) To help prevent soundboard splits at the side of the FB (angling of the extention across the soundbord grain)

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I'm doing something similar to Colin except my tail block is 12mm birch ply. Neck block is mahogany with an angled birch ply extension on top that fits flush to the UTB and for the same reasons that Colin mentioned. I do the neck block the same way whether I'm doing a bolt on or a dovetail.

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Steve Smith
"Music is what feelings sound like"

I use a headblock like this. This one is in the rough stage. it will be refined some as it is incorporated into the build.

Also, I use Honduran mahogany. It is for a M&T bolt on.

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Joe Beaver
Maker of Sawdust

I follow the same reasoning that Colin outlined. Plywood for the tail block because of its strength and resistance to cracking in this place that is susceptible to end blows (the guitar dropped on its butt), and often weakened by the drilling of a hole through it. If you don’t like the look of it you can veneer with mahogany or something else to pretty up the view through the soundhole (because people think that plywood = cheap, even when it actually is a superior material for this part of the build).

For the neck block, I am also a fan of the extension under the fingerboard, up to the UTB - and a bolt on/bolt down method. As to what material to use here - you mainly need something strong and light. Cracking is less of a problem for a neck block, compared to the tail. I use solid mahogany, but I can’t see any reason not to use ply here also.

I have in the past used an extension that is attached to the head block prior to gluing to the sides and top, but I’m currently using a regular head block and gluing a trapezoidal piece of wood in between the head block and the upper face brace after gluing the head block to the sides and top. This makes it faster and easier for me to glue the top on, and it lets me trim the trapezoid for a good, tight fit prior to glueing. For the job this piece of wood needs to do, I think both an integrated extension and a glued in piece work fine, and the separate piece makes the build easier for me.

I use mahogany for the head block, and have varied a bit on the tail block, with recent guitars using Baltic Birch, but prior guitars using mahogany. When using mahogany for either block, I run the grain parallel to the sides.

I use basswood for my neck blocks that is very well seasoned. covered with 1/16in bialtic birch ply . This provides a better gluing surface for top an back. IMHO. I like to use a baltic birch or mahogany look a like end blocks . One reason I prefer basswood , is that it is lighter, and easy to carve into any shape desired. These are for Nylon stringed instruments. For my ukes . I prefer laminated ply blocks front and standard birch or mahog plywood 3/8 to 1/2 in for the rear. block I want as little seasonal movement as possible.

Ed what you are doing is essentially making your own plywood. That's why I often do for the tail block, 3 pieces of mahogany glued together in reverse grain directions. My head blacks are typically one piece mahogany or stacked mahogany blocks. I have used spruce, walnut, oak and cherry too.

I do a stacked heel block out of mahogany or sapele, and the tail block out of Europly or Baltic birch.

M

For my travel guitars I use "baltic birch" type plywood for the head and tail blocks. For normal bolt on necks I use two layers of 1/2 inch BB ply and a facing of 1/2 inch mahogany and mahogany veneer on the sides for the head block. The 1/2 inch mahogany front allows me to radius the corners of the head block and keep the appearance of a mahogany block. For the tail block I still use 1/2 inch BB ply (3 inches wide).

Thank you all for sharing. I appreciate.

When I went up to the shop today I found a neck block I use for bolt on necks - slightly different than what I make now but the same idea. I glue them up in longer lengths and cut them off to length as I need them.

For tailblocks I use to laminate two pieces of mahogany, changing the grain 90 degrees. Now I just use Baltic birch.

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Joe Beaver
Maker of Sawdust

For tailblocks I am a fan of plywood. I also follow Trevor Gore's idea of a splint of lining material to avoid the stress at the edge of the block under the top.