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After looking at my wood I got from LMI, I'm realizing that I didn't order a heel block, just mahogany for the neck. My back and sides are black walnut, and so my initial reaction was to use the end block piece of mahogany I had for my heel block and make my end block out of walnut. So after I glued that up...



...I realized that my end block mahogany stock was way to thin for a heel block (ie not deep enough for a tenon). So, first off what do you think about my having used BW for an end block and second, what about using this wood (more black walnut) for a heel block...?



I'm mostly wondering if there will be any issues with a mahogany neck tenon joined in to a black walnut mortise?

Walnut is just fine

Zach, you might consider heating up that glue joint and removing that end block. Use it for the neck, it's much too heavy for the back end. Many of us use some 7/16" Baltic birch ply for that block. Also note tapering it down at top and bottom to the same thickness as the kerfing. Keeps the block from telegraphing after the instrument has some time on it.

I've used walnut on many guitars. I think you can pretty much use anything really. I used to make them big like that too but now they barely stick out past the linings because as Haans mentioned you get a bit of ghosting after some time. Not a real biggie imho though.

I have made a heel block by laminating walnut and it has shown no sign of failure. I wouldn't mix neck and heel block woods for a dovetail joint, but I have done so with M & T joints featuring mechanical fasteners. No problems to report so far.

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George :-)

Haans, thank for the heads up on baltic birch ply. I'm very new to this, so much of what I know is from distilled beginner-type books and videos. After searching the forums, I'm finding a lot of references to use plywood for end blocks...it still seems weird to me to put plywood in an instrument like this

Just to make sure I understand this right, telegraphing/ghosting is the bracing/blocks imposing their form on the mated surface?

jfmckenna, when you started making your end blocks smaller, did you switch to a laminate?

George, if you were to mix woods for the heel and neck again (for a M&T joint), would you make sure to laminate the heel block?

I did not switch to a laminate. It's just a stigma that I have, call it old school. Birch ply is probably the best thing to use there I just don't do it. My building style has evolved into making guitars with what you have laying around and there seems to always be a hunk of walnut, cherry, mahogany or what ever for the job. Having said that I do laminate blocks almost always. so in that sense it's a sort of ply wood I like to have the flat sawn grain on top and the end grain sticking out the sides. YEs telegraphing is when you can see the bracing make an impression on the guitars top. IMHO it usually means you have a good responsive guitar unless it's so dramatic that it starts falling apart.

Zach, yes, telegraphing is when the bracing, blocks, etc become visible as the top settles in to tension, the finish shrinks, guitar ages. Most buyers will think bracing showing up is a good thing, but a big block at the endpin telegraphing it's shape onto the top will chase them off. Some folks might poo-poo the idea of using baltic birch for the endpin block, but it actually is a "solid" idea. There is no shrinkage, and you can get away with a small block. Not that it matters much, but if you drop the guitar on the endpin, a plywood block wouldn't crack. Not a speculative person myself, but don't think a endpin block contributes much to the overall tonal qualities of an instrument.
As George says, not a wise idea to use different woods for neck joints, and I would not use plywood either.

Personally, I think it's a good idea to laminate heel blocks. I started looking into this approach after seeing references to the practice on various threads. While poking around, I found this explanation on Howard Klepper's website to be particularly useful:

http://www.klepperguitars.com/about.html#necktail

That said, I also think it's preferable to use the same material for the neck and heel block, regardless of the type of joint you employ. I mixed these materials once and that was because I was building a guitar from orphaned parts, as a means of honing my building skills. Even then, I didn't think it would be a good idea to use a dovetail.

However, there are probably a few million perfectly good guitars out in the world that use different materials for these parts (featuring both M&T and dovetail joints), so, you know, there's that.

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George :-)

Most neck blocks are oriented with a different grain direction than the neck, so IMHO the idea of using the same wood for both has very little merit.
IMHO, the most important qualities for a neck block are split resistance, medium or lighter weight, and stability.

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John

If you think it, John, I can believe it. :-)

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George :-)

for tail blocks i go with a 3 pc laminate (ala fleta) of cedro usually.
on heel blocks i use the same material as the neck shaft with a fairly big foot and a decent sized platform for the fb extension. again usually fleta 3 pc style.
fwiw, plywood, no matter how awesome, just goes against my work ethic.