Spanish cedar for headblock

[Bob Schmidt]

Is there any reason to not use spanish cedar for a headblock. This is for an octave mandolin with a bolt on neck.

[sunburst]

I don't know.
For a head block we want split resistance and some amount of strength. For a bolt-on neck we also want resistance to crushing. Moderate to light weight is also favorable.
I've only used Spanish cedar for a few things so I haven't researched it for those strength qualities, but suspect it would not quite be the equal of mahogany, which is more-or-less the standard by which head block material is judged.
I gooogled "wood strength" and found quite a few on-line references, so if I was (were?) in your position I think I would look through some of those and compare it to mahogany.

[Bob Schmidt]

Thanks John,
I compared it to Honduran mahogony on the wood database, and the hardness, rupture modulas, and crush strength are all lower so it may work, but it is a questionable substitute so I will find another use for it. It does not seem worth the risk.

[Bill McCall]

Thanks John,
I compared it to Honduran mahogony on the wood database, and the hardness, rupture modulas, and crush strength are all lower so it may work, but it is a questionable substitute so I will find another use for it. It does not seem worth the risk.

Many guitar necks were made from Spanish cedar in the 19th century. It is very stable.

[Bob Schmidt]

Bill,
Thanks. That is the reason I was considering it, especially since I have a couple of blocks of it and no mahogony curently, but I plan to get some more mahogony and use the spanish cedar for something else. It just does not seem to be worth the risk of having the neck hit and splitting the block.

[sunburst]

The only time I've used it was for a guitar neck. It worked very well for that. When neck joints (good ones, at least) fail it seems to be a head block failure more often than a neck failure.

[ProfChris]

It's stable but crushes quite easily (or can do - it's as variable as all other species). The risk is probably the bolt pulling into, but not through, the block. If I had to use it I'd laminate something tougher on the inside to spread the bolt's pressure.

[HoGo]

Many guitar necks were made from Spanish cedar in the 19th century. It is very stable.

I guess those were mostly classical guitars with low tension of strings. For steel strings and heavy tension strings mahogany became standard and even with that trussrods were added.

[Richard500]

It's stable but crushes quite easily (or can do - it's as variable as all other species). The risk is probably the bolt pulling into, but not through, the block. If I had to use it I'd laminate something tougher on the inside to spread the bolt's pressure.

Honestly, except for a certain prejudice concerning plywood in the community, it’s exactly what I’d use for a bolt-on. Even on a repair on a bowl back I did, where the neck and head block are one piece, I added a ply backing inboard to eliminate cracking and allow a strong bolt anchor. For that matter, an extremely lightweight, crack-resistant head stock at the other end of the neck.

[Bob Schmidt]

Laminating something to take up pressure on the bolt heads sounds like a good idea.

Does anyone have a good source for mahogany? What the local lumber yards sell for mahogany decking is actually Balau which looks likd mahogany but it is not. It could probably be used but it is almost twice as heavy and much stronger but it seems like overkill and the weight is an issue.

[Bill McCall]

Well, I guess you could laminate a lignum vitae faceplate to a block of stable, lightweight material. It’ll be crush resistant for sure, but perhaps a tad difficult to glue.

When I was in the shop, we made bearing blocks for ocean going ships out of the material. Tends to dull tools too.

[JeffD]

Spanish cedar is the goto for cigar humidors. Just sayin...