Spruce vs. Cedar?

[Br1ck]

I believe the redwood the SAs have been made of is reclaimed timber from buildings. There is also the reclaimed sinker from ols submerged logs, a topic in and of itself.

[Dale Ludewig]

I've made 4 mandolins (several more in progress) from some redwood I got from Spruce. Unbelievable stuff. Some, at least, is from the Sullivan stash. About half the density or "normal" redwood but with the same rigidity. Incredibly light and very loud. I've kept 2, an ff hole and an oval hole. They both need flat-wound nickel type strings or they're a little harsh. When you match the string to the instrument, the tone and presence is remarkable. I personally have concerns about it splitting, so I've bound the ff holes or oval holes as kind of insurance.

[Max Girouard]

Max your comment on the dimensional stability of WRC brings to thought a couple questions? Do some woods absorb moisture more readily than others? What is the relationship between a woods dimensional stability and its porosity. We seal the outside but the interior is open to soak up whatever moisture available when the case is opened. Generally there isn’t much endgrain exposed if any inside the instrument. Now that we have cooked wood options does autoclave oven drying change the woods absorbent qualities as well as making it more brittle and prone to splitting? I wonder if woods like cocobolo with oily pores could be improved for adhesion thru autoclaving.

From my experience, the more dense and oily woods will take on moisture more slowly, like they have their own natural finish. A good expample is Lignum vitae which has such a high oil concentration as well as being extremely dense that you can spray water on it and it will bead up, whereas if you sprayed a piece of maple or spruce, it would quickly soak into the wood.

I don't have an answer to your question about a relationship between woods dimensional stability and its porosity.

As I was told by a guy selling torrefied wood, treated woods will not take on moisture from the outside environment. He was referring to the extreme torrefaction they use to treat lumber for outdoor use. It looks like dark chocolate when it is done. The wood I have personally used for a couple mandolins has been torrefied at much lower times and temperatures and has a honey amber to dark amber appearance. These samples did absorb moisture when we wet them to raise the grain during sanding.

[treidm]

So if a luthier uses "torrefaction" for wood. is that a form of heat treating the wood to speed the aging process and remove excess moisture, and thus stabilizing the wood?

Very interesting subject...
Reid

[hank]

Max, I asked because I had a reclaimed Claro Walnut stump carved plate and a Carpathian Spruce carved plate out when a sudden high humidity hit our area. The Claro stayed flat but the walnut bowed slightly. The bow was lateral like the sweep of a gouge from one side to the other. Both examples were quartered two piece plates. The walnut returned to it’s original flat condition shortly after the humidity went down. As an opposite example my thicker black walnut neck for those plates stayed straight without change during our wet conditions.

[George R. Lane]

Uh, Hank

You might want to read your second sentence, It states the Claro Walnut both stayed flat and and bowed at the same time.

[soliver]

Per the prior delineations, which Cedar?

My bad, MM, its Western Red. I had met up with David Mold (OldSausage) to give his Siverangel A a try and loved the tone. His was WRC over Soft Maple so I had Ken Duplicate that.







As a side note relative to the discussion re Redwood, Ken Ratcliff is regularly using old growth Redwood on many of his Silverangels, some of them being the "sinker" redwood which has been dredged up from the bottom of bodies of water (as mentioned by Br1ck above).

[hank]

Thank you George. I should proof read more. The Carpathian Spruce stayed flat while the Claro Walnut slightly bowed.

[Max Girouard]

So if a luthier uses "torrefaction" for wood. is that a form of heat treating the wood to speed the aging process and remove excess moisture, and thus stabilizing the wood?

Very interesting subject...
Reid

Yes, the wood is put into a special kiln that draws out all the oxygen. The wood can then be heated past the combustion point of wood without igniting. There are several people I know of that are using torrefication and have been experimenting with lower temperatures and times to get different "roasts". I have not had a lot of experience with torrefied spruce, building with our first top now. I've built a handful of instruments with treated maple, and I feel that difference was a boost in volume as compared to the untreated instruments we built at the same time. As far as aging the wood, I wouldn't say it's doing that as it's completely changing the structure of the wood in a way that nature wouldn't through time. Maybe similar in some ways, but definitely different. It will be interesting to see how the torrefied pieces sound as they age.

Max, I asked because I had a reclaimed Claro Walnut stump carved plate and a Carpathian Spruce carved plate out when a sudden high humidity hit our area. The Claro stayed flat but the walnut bowed slightly. The bow was lateral like the sweep of a gouge from one side to the other. Both examples were quartered two piece plates. The walnut returned to it’s original flat condition shortly after the humidity went down. As an opposite example my thicker black walnut neck for those plates stayed straight without change during our wet conditions.

I remember that happening when I was just building as a hobby, and did not have a dehumidifier in my "shop" which was a corner of a dining room. I've had that happen with maple as well as walnut and birch. Definitely helps to get the humidity under control in your shop to prevent that from happening. But it can also happen if the wood has internal stresses that are released during carving. Those examples usually don't return to flat, but can be convince to straighten out with clamp pressure.

[Papalobo]

My mandolin is a port orford cedar top / myrtle body F5 style , I would agree that the cedar top allows for a slightly warmer , i.e. more lower mids and more open sound . The character of the luthier still comes through ( Weber) .