Maple burl for backs

[Magnus Geijer]

I spotted an exceedingly pretty piece of maple burl the other day, in a size almost perfect for a mando back, and with amazing figure, but then I started to wonder about the strength of the wood. Would a burl piece have the structural integrity needed for a mando back?

/Magnus

[Chris Baird]

I don't think so. I use burl for veneer and it is much weaker than normal maple.

[joshags03]

I'm sure someone will correct me if I'm wrong but I think it would be ok to use burl for a back. Although it doesn't have the structural integrity of "regular" maple, the back of a mandolin doesn't really have to carry a lot of load. Main thing I would be concerned with is what kind of sound you will get. While hard maple transmits vibration easily, burl may dampen the sound or give a muddy sound. You could also leave the piece a little thicker than what your plans call for. That should make up for any strength concerns you may have.

[John Bertotti]

I asked the same thing several years ago and the consensus was it wasn't a good idea. As an experiment perhaps. But if your looking for longevity there are a whole lot of factors that can bite you. Ie how tight the burl is how well it is adhered to the surrounding wood etc.. John

[Spruce]

"Would a burl piece have the structural integrity needed for a mando back?"

It really depends on the burl.
Here's a pic of a piece of European Maple that I found in England last week, and I think it'll be fine for a one-piece violin/mandolin back. #There's enough of the tree itself present in the piece to give it structural integrity, as opposed to some burls I've milled which, if it just contains burl and nothing but burl, is more akin to a sponge than wood.

That being said, I've seen some old French fiddles made of this type of #burl, and they seem to have held up fine over the years, even with that soundpost pushing on that spongy wood...

[sunburst]

Spruce,
I was offered a Maple tree with a lot of big burl the other night. The guy said the tree was growing next to a spring, so I asked if it was Silver Maple and he said yes. Should I even go and look at this tree?

[Big Joe]

IF you like turning wood, it is wonderful!

[Spruce]

" Should I even go and look at this tree?"

I make it a point to look at every tree that might be coming down...

I've seen trees that are loaded with burls on one side of the tree, and loaded with clear fiddleback on the other side....
So you just never know....

Silver Maple is a fav of mine, especially for instrument makers who like working with a lightweight maple...
You see it all the time in Gibson instruments from the 30's-40's, cut on the slab, with a distinctive popcorn figure that is vaguely reminicient of quilted Bigleaf maple....

[sunburst]

OK, I'll go look. Silver maple has not been a favorite of mine, seeming sort of tough and stringy when worked, but I have seen some nice quilted figure in some of it.

As for turning, Big Joe, I'd feel like it should be rough turned green to avoid drying problems, and I don't have a big enough lathe right now or the time to mess with it. I feel like wood keeps better while it's still in the tree if I'm not ready for it.

[Andrew Reckhart]

I'm going to show my ignorance......... What is burl?

[oldwave maker]

Did a fiddlemaking apprenticeship long ago with bob crawford. he won the bob wallace tone award (blind judging by tucson symphony players) at the '92 vmaai convention against 120 other fiddles with an outrageously burled maple fiddle with a colorado engelmann top I brought him from a firewood pile in breckenridge colo. he had to reinforce the pegbox with hard maple from the inside. been eyeing a giant sycamore burl in a 23'circumference tree just upstream from the shop on the neighbors place. could harvest it some dark stormy night with the elec chainsaw if I can put together a 600 ft extension cord.
got this one from spruce at vmaai last october, should be ready for light and lively ovalhole backs in a few years, wouldnt use it on an f holer tho, especially when surrounded by inebriated banjoplayers...

[sunburst]

What is burl?
Here's the best description I found in a quick search.

Burl (http://www.ca-walnutdesigns.com/burl.htm)

[Spruce]

Wow....
I forgot about that chunk Bill...
Pretty psycadelic even this early in the afternoon...

[cameron]

Please forgive my ignorance;what is the difference between burl and birdseye? If a birdseye back has very few eyes is it harder or softer than one with many eyes? One of the best soundng mandolins I have ever heard has birdseye back/sides/neck(lots of bird's eyes and made by Steve Gilchrist.)
Les,Why would you not use burl on an F-stytle(besides the drunk banjer pickers?) Too fragile? I don't understand the "spongey" aspect of the burl;is it just soft?
TIA,
cameron

[Spruce]

Birdseye is a figuring that occurs in Sugar Maple (and rarely in Euro maple) that is in solid wood.
I've never gotten a straight answer as to what causes it...

See pic...

Burls are growths on the side on many species of wood, that are very "spongy" and light-weight compared to the wood it grows on.

They look a little similar, but are very different...

I agree on birdseye maple for mandolins. The Sullivan I'm playing right now is made from birdseye, and it's a blaster...

[whistler]

Burls (or burrs, as we call them in Old England) are worth having for veneer, if nothing else.

I believe birdseye figure is caused by attack from a certain type of insect. The tree reacts by repairing the damaged areas with harder, denser wood, causing small, knot-like markings... or that could be some other kind of figure.

Birdseye maple is actually regarded by some people to be stronger than unfigured maple.

[Spruce]

Hi Whistler...

Do you ever see English sycamore with birdseye (not burry) figure?
I know it exists, but it seems to be exceedingly rare, especially in England.

Thanks!

[HoGo]

I read one research article that said that about 10% of maple trees here in Slovakia have some kind of figure (mostly fiddleback, but I've seen very nice quilt as well) and only 1% have the birdseye figure. In some regions the figured trees are quite common in others not, because it is mostly genetic. I read that birdseyes are "sleeping" knots. If the surrounding trees are cut and the trunk gets direct sunlight the new branches will grow from them.
I know one maple near my home with a lot of "burls" all around the tree. Reminds me of cancer... 15" diameter still needs some time to grow.

[whistler]

Bruce - I think I have heard of birdseye sycamore, but I haven't seen it. I'm a relative beginner to instrument making, and to woodwork in general, so there may be some around, but it's certainly not common.

[Magnus Geijer]

As always, brilliant response. I'm planning for my #5 to be my masterpiece of sorts (at leat for the moment), and I believe I'll go for a burl back. Thanks again.

/Magnus

[labraid]

Just my two cents, having studied wood (and late on jumping in here for just having joined!)... But the grain in burl is so unpredictable, and often weak in places, fissures could possibly form over the years from expansion/contraction from humidity/temp changes.. Fatigue + Wild Diseased Grain = Cracks? I wouldn't put it past our good ole friend, wood, to pull a trick like this. I'd be so bold as to coat the inside with glue-saturated (lightly!) canvas, or even epoxy paint if yer a grey-tape kinda guy. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif Sometimes we must sacrifice for beauty. But again, it all depends on how burly (not birdseyey) the grain is and if it surrounded by mostly sound grain... Burl is some weak stuff indeed, all by itself. I had always understood it is a badly diseased portion of the tree, sort of a cancer that starts from a wound and ends up as a very bad self-repair job.

[Rob Powell]

Hey Bruce...

You still got that piece of birdseye you posted a pic of?http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gifhttp://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[oldwave maker]

that aforementioned sycamore burl on the hoof, so to speak, about 3' high, 4'wide

[Spruce]

Check out this fiddle (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=16225&item=3736219662&rd=1) for an extremely attractuve use of burl in the back on an instrument...

Probably Chinese maple....

"IF you like turning wood, it is wonderful! "

Again, it depends on the integrity of the burl as to whether or not it's usable for the back on an instrument.
The wood in the Chinese violin looks like it has some strength to it, and makes for a very attractive look, no?

Wonder how it sounds....

[Mario Proulx]

Bruce, if that fiddle's back is burl, then yes, it makes a great mandolin. I made one from a very similar slab of maple many years ago that is perfectly stable to this day, and sounds great, with a warm, full tone.

I always wondered what to call that figure.......

[Michael Lewis]

That stuff is some of the most unusual and even figure I have seen. I would call it quilted burl or burled quilt. Verryyy inntterressting.

[Spruce]

Watch out for maple coming from China...

I've seen some amazing looking stuff in Chinese instruments in the past few years, and it's only a matter of time before the raw material starts showing up in Europe and North America...

I might have to go over there and have a look myself....