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Just got my first sets of redwood.

I had expected it to have a high, clear, glassine tap tone much like cedar. The freqs are way, way low compared to other wood in similar dimensions. I can't cut it into perfect rectangles all Trevor Gore's method without losing the ability to return it, so I can't collect meaningful data in the normal fashion. Just wondering what others experience with redwood indicates. My thinking is that I've got some wood I want to return, if I can...

Should I be expecting a cedar like tap tone?

Yep.

Ed: Have not used Redwood very much but my limited experience says that it rings very easy, the ring is loud, and sustain is quite long. Any Redwood I've had rang as good or better then any Spruce I've had.Have not had a cedar top in my hands since the 70's so no help there.

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A person who has never made a mistake has never made anything!!!

I think I got dudded.

Send it back if it goes "Thwack" or "Splat" instead of "bong" when you tap it. This sort of redwood typically suffers from internal crushing or fracturing of the cells from the weight of the tree - and it will crack in half when you flex it good. Or it will crack in half spectacularly once you string it up.

If it's just a lower frequency resonant bong - it's probably just a very light piece of redwood... Fine stuff for a finger style or classical.... Not so hot for a bluegrass dread or anywhere you want a lot of headroom.

Thanks

I'll try to get some stats later. Presently, there is nothing making me go yahoo!

If you want to be amazed, get some of Dave Maize's AAA or master grade

Here's some quick stats...

Of the three sets I got, one sinker, two non, one non sinker top has some decent ring to it, though the pitches are low.
268 g
609 x 215 x 4.5mm = 589.2 cm3
268/589.2= .45g/cm3

Which is as high as pretty dense sitka.

Short grain freq is 157.4hz
Long grain is 54.8hz

I've been able to use the chapter summaries in the Gore/Gilet books quite handily, but the initial equation for thicknessing tops evades me, being written in math and all.

Anyone who uses it know if those freqs are anywhere in line with 'useable' wood? My books are still buried under a pile of renovation rubble...

Does it have evidence of a lot of compression wood/thick late growth? That would explain the higher density with a relatively lower stiffness making the low tap. If so - it may be good if you are looking for a top with headroom. Not so good if you are aiming for super responsive to a light touch.

Thanks

Ideally, I'd need a diagonal tap frequency as well, but taking a guess at that I get Elong=8.7GPa and Ecross= 1.1GPa, compared with my averages for redwood of 11.7GPa and 0.9GPa. My average density is 435kg/m^3.

Design top thickness comes out at 3.16mm with a top panel mass of 208grm for my medium SS (about 000 size), compared to what I've used, with an average panel mass of 174grm.

If that's the best piece, I wouldn't be rushing to use the rest. Brian Burns, who does a lot more testing of redwood that I do, reckons it's one of the most variable species.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

I gave you a set. I hope you know where it is. Don't know about the tap tone but it makes outstanding guitars. Dig around the pile. You won't be disappointed.

I think I know where it is...I'll do some data collection on that as well.

So, .450 is not that much denser than .435. For some reason I had expected redwood density to clock in close to .300 like cedar...even the sinker piece is .460...

I loved building with RW and my impression of the tap tone is a cross between great sitka and Adi. The resulting instruments IME have very strong fundamentals but lusher overtones more like cedar in the overtone respect but louder and projecting better than cedar and more like adi. It's a great sounding wood and will snap in half along the gain with little or no warning so be careful flexing that puppy....

Consider a wash coat too of ep*xy even though it's a top because the color pop is very, very pretty!

I found that set Danny, it's .41, which seems the best of the bunch...

You will not be disappointed.

Where did you get the other Redwood? I have to go hound my buddy where that set came from. He has a stash of quarter sawn boards from 30 years ago.

Hesh wrote:
"I loved building with RW and my impression of the tap tone is a cross between great sitka and Adi."

Most of the redwood I've used, and tested, comes in with density and stiffness numbers very much in the range of the stiffer Sitka and Red spruce, but with low damping, more like Western Red Cedar. I've always thought of it as 'cedar on steroids'. Like WRC it does have a tendency to split, so you have to keep that in mind, using a wider bridge, for example, to minimize the chance of it peeling up.

Last year I got some redwood that was totally out of character. It was dense, but had relatively low long grain stiffness, and high damping: it tapped like cardboard. I sent it back.

I have a book that might explain that, called 'Growth Stresses and Strains in Trees', by Archer. Green wood tends to fail first on the compression side when it's bent, with the cells crushing inward to allow it to buckle. Trees have evolved a mechanism to avoid having wood in compression, at least around the outside of the trunk: each new layer of wood that's added is pre-stressed in tension. This puts a bit of compression stress on the wood further in, but since that's not as important for keeping the tree standing it doesn't matter much. On very large trees it is possible for the weight of the tree plus the built-in compression to actually exceed the compression strength of the wood. In that case it fails via microscopic cracking. You can't see it, but wood like that will 'brash fracture' when bent, breaking cleanly across the width almost looking like a saw cut. I suspect that's what happened with that redwood. Some I've seen has has a sort of 'crushed' look, too; sort of a 'wrinkled' grain that is more random than the usual curly stuff. The wood I got last year was 'salvaged', possibly from old stumps. The supplier had sanded it to thickness, and I could not plane it off get a really good look at the surface if I was going to send it back. Wetting it with a solvent did show some of that 'crushed' look, though. I'm not saying this always obtains with stump wood: the famous LS redwood was stump salvage, ant that's great stuff. It's just something to be aware of.

Well, out of three sets, only one has any tap tone, and it's sounds more like spruce than cedar. I had very much expected it to be a clear, crystalline, glass like tap tone like cedar. And at .45 and .46 density, I'm not overly enthused. I'm going to send it back if I can cause it was butt expensive.

This is an interesting discussion. I am resawing through a giant stack of wood I bought during a stint of binge wood hoarding.

I had 3 different pieces of redwood in the stack. 1 very light weight and very wide grained - like 4-6 rings/inch - but the slices tap awesome. Another feels like about 2x the density and is much more fine grained. The stuff taps like it is very high density and low stiffness - a very low melodic tap. The last is somewhere in between. All I can say is that there is a lot of variation in redwood.

Thanks

Indeed there is.