Laminated curly redwood top

J

JJohansen

Well-known member
Joined
May 8, 2018
Messages
76
Reaction score
26
Hi everyone,

I seem to remember reading that some builders will laminate curly redwood to a straight grained backer to strengthen it. Have any of you guys tried this approach? It seems like a good idea from a structural standpoint, but I am unsure what it would do acousticly. I'm also wondering if one could laminate a curly redwood top to a spruce backer and change the sound in any appreciable way. I'd hate to make a lackluster sounding instrument for the sake of fancy wood.

Thanks!
Josh
 
Making quality wood laminates for musical instrument tops requires some very specialised and sophisticated machinery to (A) precisely cut extremely thin layers and (B) to evenly pressure-bond those layers into suitably thin plates.
My 'home job' attempts at this ended in dismal failure.
The main, but not the only problem, was that my set up could not deliver an adequate and even pressure to keep the glue line consistently thin.
When reduced (planed, scraped and sanded) to ~ 2.8 mm the resultant plates sounded quite 'flubby' and lifeless... many hours of work for no gain.
I am sure that others would have the ability to do a better job than I did, but I concluded that a quality piece of solid Spruce or Cedar should produce a better outcome for a fraction of the effort... even if they do look plain and uninteresting.
This was for guitar not ukulele.
 
Last edited:
JJohansen said:
I'm also wondering if one could laminate a curly redwood top to a spruce backer and change the sound in any appreciable way.
Click to expand...

I can almost guarantee you it would sound awful. The spruce would effectively dampen the redwood and the redwood would effectively dampen the spruce cancelling each other out. Getting plates sufficiently thin enough to laminate (let's say 0.040" for each (~ 1mm) for a final of 0.080 or ~ 2mm would be difficult without sophisticated machinery as bazuku points out. I have made tops of redwood which were highly figured with no resultant problems. Just go ahead and thin your properly seasoned "curly" redwood (pictures would be nice of the wood in question by the way), brace properly and you should be okay.
 
"Flubby"

What a wonderful word. I know just what you mean!

John Colter
 
sequoia said:
I can almost guarantee you it would sound awful. The spruce would effectively dampen the redwood and the redwood would effectively dampen the spruce cancelling each other out. Getting plates sufficiently thin enough to laminate (let's say 0.040" for each (~ 1mm) for a final of 0.080 or ~ 2mm would be difficult without sophisticated machinery as bazuku points out. I have made tops of redwood which were highly figured with no resultant problems. Just go ahead and thin your properly seasoned "curly" redwood (pictures would be nice of the wood in question by the way), brace properly and you should be okay.
Click to expand...

I'm not so sure though. I did some rooting around in the archives and saw that Beau H says he laminates curly redwood to spruce, and I've read that another well respected maker will laminate to straight grain redwood. If the acoustic success of a top is largely a function of stiffness and weight, I don't see how two well mated laminates with the grain co-planer would change all that much from a solid top. I'm not sold on the idea, but it would be a pretty neat technique to have on hand. As far as tooling, I don't think it would be that hard really...I'm used to sanding shop sawn veneers down to 1mm, and would press the flow together with a vacuum press.
 
sequoia said:
I can almost guarantee you it would sound awful. The spruce would effectively dampen the redwood and the redwood would effectively dampen the spruce cancelling each other out. Getting plates sufficiently thin enough to laminate (let's say 0.040" for each (~ 1mm) for a final of 0.080 or ~ 2mm would be difficult without sophisticated machinery as bazuku points out. I have made tops of redwood which were highly figured with no resultant problems. Just go ahead and thin your properly seasoned "curly" redwood (pictures would be nice of the wood in question by the way), brace properly and you should be okay.
Click to expand...

I'm not so sure though. I did some rooting around in the archives and saw that Beau H says he laminates curly redwood to spruce, and I've read that another well respected maker will laminate to straight grain redwood. If the acoustic success of a top is largely a function of stiffness and weight, I don't see how two well mated laminates with the grain co-planer would change all that much from a solid top. I'm not sold on the idea, but it would be a pretty neat technique to have on hand. As far as tooling, I don't think it would be that hard really...I'm used to sanding shop sawn veneers down to 1mm, and would press the flow together with a vacuum press.
 
Some high end classical guitars are built with "double tops". Two very thin layers of tone wood separated by Nomex or similar material. Has any one tried this with a ukulele top?
 
kkimura said:
Some high end classical guitars are built with "double tops". Two very thin layers of tone wood separated by Nomex or similar material. Has any one tried this with a ukulele top?
Click to expand...

Indeed, there is such a thing as the "double top" soundboard that I was unaware of. Live and learn. Below is a quote and a link to a website about them.

First a word about nomenclature. While this style of guitar is most commonly referred to as a ‘double top’ guitar, a more accurate depiction would be implied by the use of the phrases “sandwich top’ or ‘composite top’. Double top implies that there are simply two components to the soundboard, two independent soundboards glued together under pressure. In actuality all double tops are actually three layers, the inner top, the outer top, and a middle core which at this time is usually composed of wood, Nomex, or a blend of the two. But the phrase that has caught on is ‘double top’ and so I use that freely here.

https://classicguitar.com/the-origin-and-development-of-the-double-top-guitar/
 
Interesting how views of certain woods differ. Although 90% of my ukes have koa tops, I've made a number of redwood top guitars and ukes. I only use curly redwood, and I've never felt a need to laminate the top. I think it makes a great sounding uke, and the look is stunning! I probably try to compensate for the weakness caused by the curl by leaving the tops a few tenths of a mm thicker than I would straight grained wood. I bought most of it on eBay a few years back, before it became popular. These days eBay curly redwood is a little off the deep end. The wood can be a slightly risky to build with. Wide, heavy curl is particularly dangerous.Regular straight grained redwood can be easily dinged during construction, but I find the curly wood to be a little harder. If you are not up to the challenges that curly redwood can bring, like finding a crack in a curl line and having to discard the top and start over, then curly redwood is not for you. However I find the results of a successful build with it to be very rewarding. Enjoy your building!-Bob
 

Attachments

  • redwood2.jpg
    redwood2.jpg
    83.6 KB · Views: 28
  • DSC_0591 copy.jpg
    DSC_0591 copy.jpg
    96.3 KB · Views: 26
  • Red.jpg
    Red.jpg
    100.1 KB · Views: 27
  • redwood3.jpg
    redwood3.jpg
    71.7 KB · Views: 23
ukantor said:
"Flubby"

What a wonderful word. I know just what you mean!
Click to expand...
Apologies!
'Flubby' is a vague term that should in no way be associated with good lutherie nor be injected into the lutherie vernacular.
Sequoia well nailed its literal meaning.
By way of clarification, imagine that I was trying to coax Fraulein Maria's musical 'Do' from my composite soundboard, but after hours of frustration and 'refinement' the best it could offer up was Homer Simpson's much less musical 'D'oh'....with Homer still in mind, conjure up “flubby”.
Now to a more sensible comment....
I concluded that uneven glue layers were the culprit in my failed results. When I eventually ran the flubby soundboard through the band saw multiple times, the resultant strips showed a significant variation in the thickness of the glue layers and several glue 'pockets'. To me, this indicated that the pressure and technique applied were not up to the task. Most persistent and enduring builders would have taken up the challenge to overcome those issues, but not me, by that stage I had had enough 'mucking about' and begrudgingly relegated it to firewood, never to revisit.
None of my experiments into laminating have made it to the stage of being used in a finished instrument.
 
Michael Smith said:
My opinion is redwood makes lousy ukulele tops. I have made a few but won't any more.
Click to expand...

Redwood is my favorite wood for tops. Warm with great volume, sustain and 'round' bottom end. Of course, the redwood I use is from water tanks that used to be on the top of New York City apartment buildings, so it has been aging up in the sky, filled with water, for 50+ years.
 
Some pictures of a sinker redwood topped ukulele I made some years ago. Note in picture two the CA glue staining in the left lower bout. This is when I learned that redwood is notorious for wicking CA glue. Sealing with shellac would have prevented this. After finishing, the wicked stains were not noticeable (unless you knew where to look).

redwood1.jpg redwood2-1.jpg redwood3.jpg redwood4.jpg redwood5.jpg
 
I would never use curly redwood without laminating it with spruce or cedar.

When I do this the top comes out about the same thickness (around .080") with no loss of tone- the spruce probably makes the redwood better actually.

Glue the spruce grain so it crosses the grain lines of the redwood- about 10 degrees or so usually does the trick

What makes Curly redwood beautiful also makes it completely unstable- at least the sets i've worked with.

I has since taken it off my order form as even laminated it fails very, very easily- see the video below

Straight grained redwood is an excellent topwood which should be handled similar to cedar.

 
You must log in or register to reply here.

Similar threads

Timbuck
Laminated end block
Replies
8
Views
662
Diogenes Blue
Diogenes Blue
E
Strings for solid top, laminated B&S
Replies
6
Views
567
Graham Greenbag
G
A
Pono Sopranos possibly have laminated fretboards?
Replies
4
Views
489
Graham Greenbag
G
K
WTB: Romero Creations XS soprano, laminated is better
Replies
2
Views
462
kunshiniki
K
C
FS: Rare Kala Fretless U-Bass Solid Spruce Top/Laminated Mahagony Back&Sides
Replies
4
Views
514
chrimess
C
Top Bottom