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View Full Version : Preparation of Head and Tail Block Ends Prior to Gluing Tops and Bottoms?



taylordb
01-23-2016, 05:36 AM
Looking for some advice as I proceed with my first build.
I have my sides bent and glued to the head and tail blocks.

For the back, I have sanded the sides in a 15' radius dish and am wondering how to treat the entire surface of the ends of the head and tail blocks. I can think of two different ways to go:
1. Continue sanding in the radius dish so that the end faces of the head and tail blocks follow the 15' radius, and will be in full contact with the back upon glue-up....or
2. Project an imaginary line of the kerfing across the tops of the blocks and then provide relief on the block ends outside of the kerf line so that the back comes in contact with the block ends only along where the imaginary kerfing would go.


For the top, I am thinking of sanding the sides flat at the upper bout and to a 25' radius below the upper bout. I am thinking that the face of the head block should have full contact with the top upon glue-up. For the face of the tail block I am thinking it should be prepared like case #2 above for the back.

What are others doing? Thanks so much in advance for your help.

Beau Hannam Ukuleles
01-23-2016, 06:16 AM
I:
1- Bend the sides and fit into mold
2- Glue in the head and tail blocks over size
3- Block plane down the head and tail blocks to the height of the sides- rough tail block to thickness of future kerf linings.
4- Radius back (I block plane off the major high points before "driving the bus")

5- Glue in kerf linings slightly higher then radiused sides- Make the linings higher in the waist as that it the 'highest' part of the 15' dome. (know what i mean?)

6- Radius again so kerf linings are radiused.
7- Fit back

Tail block same width as kerf linings.
87685

Allen
01-23-2016, 09:44 AM
I always relieve the edges of the tail block to correspond with the width of the linings. Otherwise it's very often the case that you will see the tail block footprint being "mapped" through to the soundboard and sometimes to the back as well.

Michael Smith
01-23-2016, 10:33 AM
I do same as Allen.

Unlike Beau I bring the sides down to meet the blocks. Rouged out sides are slightly wider than blocks.

taylordb
01-23-2016, 11:40 AM
Thanks everyone. I will relieve the edges of the tail block to make the contact area with the top and back the same as the width of the kerf linings.

My logic says that you would do the same for the head block where it meets the back. Would this be a correct assumption?

How about where the head block meets the soundboard....full contact all around? This seems like it could provide better support for the fretboard.

Beau Hannam Ukuleles
01-23-2016, 12:56 PM
No- keep the headblock full thickness, and make it WIDER then the fingerboard

taylordb
01-23-2016, 01:27 PM
No- keep the headblock full thickness, and make it WIDER then the fingerboard

My headblock is 2 5/8" wide, which is wider than the fingerboard, so I'm good there.

Beau, just so I'm clear about it, you keep the headblock at full thickness for both the top (at the soundboard) and the bottom (at the back)? I understand keeping it the full thickness at the top (soundboard), but am wondering if I should provide relief at the bottom where it meets the back. Also do you apply glue across the entire face of each end?

I apologize if I'm coming across a little dense on this :-(