Beveled tail block

[Roger Häggström]

I'm always looking for something new for me to try. I had a classical guitar in for repair, the guitar had been dropped and the the top was loose from the tail block. Needed some glue, but I noticed that the top was only glued to the rim of the tail block, it had a bevel on top and the gluing surface for the top was as wide as the kerfing. The rest of  the block had normal thickness.

Thinking about it this is not a bad idea, should "unlock" the top around the tail block.

The drawback is that the construction will be weaker.

Any opinions about this detail?

[Glen H]

Well, I do the same but on steel strings.  So far no problems with it.

[Roger Häggström]

When you did it the first time, did you hear any improvement of the tone? :-) The area around the bridge is very important, a small change like this may give a positive effect.

[Glen H]

I've done this the past oh about 15 builds, which for me is about the past ten years.  I can't say with my level of experience what this contributed to sound change. I guess it's just left to theory for me.

[Murray MacLeod]

This area isn't around the bridge.

The construction isn't "weaker" in any meaningful way, it just means that  the gluing surface is the same all the way round the perimeter of the top. Except at the neck block, which has to have a fully glued area to function as a structural component. The tail block has no such structural function in a flat top guitar, other than to provide a gluing  surface for the end graft and the joint of the sides in the lower bout.

[Roger Häggström]

The end block itself must have some thickness and strength to be able to hold for a blow to the end pin (from a dropped guitar). I have seen many skinny end blocks when doing repairs almost as thin as the kerfing and they have all been cracked or loose. It was a short lived hype among Swedish guitar makers in the 1950s.

[Howard Klepper]

I always make them like that, both top and back edges.  No problems.

Tone?  It couldn't hurt. 

I always put a laminate on the inside face of the tail block running crossgrain to the rest of the block to prevent cracking.

[Roger Häggström]

Thanks :-)

[Hesh Breakstone]

Lots of builders do this and tone is too subjective for anyone who is not breathing their own air.... to comment with authority on.  I also built all my guitars this way.

It's done for two primary reasons that I am aware of.

First with the idea that it may....... it may.... open up the lower bout some as is the reason why Taylor and many small builders thin or rabbit their tops around the lower bout at the edges.  Smaller guitars, like what you often seem to deal with, may... benefit in the bass department because it effectively frees the top a small amount in the tail block area.

Does it work?  Do some testing, develop methods to measure volume and frequency response consistently that DO NOT rely on human perception and also develop a method to drive the instrument over and over again consistently, an automatic plucker if you will and find out.

It's also done to prevent in time a "pucker" that is visible in the top where the top is glued to the entire tail block.  Over time the top develops it's belly and in the tail block area the tail block glue joint often telegraphs through and shows on the outside of the instrument.  In this respect it's a cosmetic issue that is being addressed, in time of course.  You can see this pucker on older import instruments with distorted tops and very thick finish that reflect the light enough to show top distortion.

I've also known builders who use "active backs" as did I and they were known to do this on the back side of the tail block too also to presumably open up the back further than thinning and flexible bracing will.

[Roger Häggström]

Thanks! There are many good reasons for making a bevel like this. Never thought abut the "pucker", but the neck block have similar problems for sure so why not the end block.

I will try it out for all the reasons presented here. On a small guitar the effect on the tone will be greater than on an big guitar, will be interesting to see how it turnes out. I'm hoping for a bit more bass :-)

[charley erck]

We use an automatic plucker on our chickens, and I am two generations away from Appalachia!
It's odd to think of a measure of tone that doesn't rely on human perception, as it's humans that are gonna be listening to them! But, I get what you mean. By the way, Hesh, I immensly enjoy your postings and responses.
You are genious and a generous man to share on here as you do!

[Roger Häggström]

I'm pretty sure that I can hear if there is a big enough change in tone. No guitar sounds the same, but all the parlors I restore using my concept share the same tonal expression. They all share the same basic sound, after all I do the same thing to all of them. Time will tell.

[Hesh Breakstone]

Thanks Charley!!! ;)