Brazilian Teak any good for making a backed longbow?

How to make a Bow, a String or a Set of Arrows. Making equipment & tools for use in Traditional Archery and Bowhunting.

Moderator: Moderators

Post Reply
Message
Author
Bormin
Posts: 27
Joined: Tue Jan 08, 2013 5:53 pm
Location: Port Macquarie, NSW

Brazilian Teak any good for making a backed longbow?

#1 Post by Bormin » Sat Jun 04, 2016 6:22 pm

Just saw an ad for Masters now supplying what they call Brazilian teak decking.
Does anyone know if it's the same as what's listed on the wood database http://www.wood-database.com/lumber-ide ... ds/cumaru/

Is it any good for bow making? Sorry, but the numbers are pretty much meaningless to me.
Apparently very dense which is promising but the grain is interweaving which is not good?

Specs below.


Cumaru (Dipteryx odorata)

Common Name(s): Cumaru, Brazilian Teak

Scientific Name: Dipteryx odorata

Distribution: Northern South America

Tree Size: 130-160 ft (40-50 m) tall, 3-5 ft (1-1.5 m) trunk diameter

Average Dried Weight: 68 lbs/ft3 (1,085 kg/m3)

Specific Gravity (Basic, 12% MC): .86, 1.09

Janka Hardness: 3,330 lbf (14,800 N)

Modulus of Rupture: 25,390 lbf/in2 (175.1 MPa)

Elastic Modulus: 3,237,000 lbf/in2 (22.33 GPa)

Crushing Strength: 13,850 lbf/in2 (95.5 MPa)

Shrinkage: Radial: 5.3%, Tangential: 7.7%, Volumetric: 12.6%, T/R Ratio: 1.5

Cheers,
Bormin

User avatar
greybeard
Supporter
Supporter
Posts: 2992
Joined: Tue Feb 07, 2006 9:11 am
Location: Logan City QLD

Re: Brazilian Teak any good for making a backed longbow?

#2 Post by greybeard » Sun Jun 05, 2016 7:46 am

At $4.99 per lineal metre it may be worth a try. Bow design as always will have a bearing on the outcome.

Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken.
[Ascham]

“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]

I am old enough to make my own decisions....Just not young enough to remember what I decided!....

hunterguy1991
Posts: 859
Joined: Mon Jul 09, 2012 10:18 am
Location: Woodford Queensland

Re: Brazilian Teak any good for making a backed longbow?

#3 Post by hunterguy1991 » Sun Jun 05, 2016 10:25 am

Hit and miss mate... some boards will make a bow, others that look the same have bad soft spots in them, though thinking about it now I was pushing the wood pretty hard :biggrin:

It should go ok for bows up to 50lb or so and keep them fairly long to keep the strain down a little.

Bormin
Posts: 27
Joined: Tue Jan 08, 2013 5:53 pm
Location: Port Macquarie, NSW

Re: Brazilian Teak any good for making a backed longbow?

#4 Post by Bormin » Sun Jun 05, 2016 3:15 pm

yeah I was thinking a simple 68" pyramid design backed with boo of course (still got tons of it).
I'll keep the boo thin this time so as not to overpower the belly. I've wrecked too many bows with compression fractures.
Although, I think most of the problems I've had been due to being too bloody impatient and not exercising the limbs enough during tillering.

Daryl, we don't have a Masters in Port and the Bunnings here stopped supplying spotted gum or anything really other than merbau so just wanting to know if anyone's had any experience with Braz teak before I go for a drive down to Taree for one board :)

Cheers,
Bormin

User avatar
greybeard
Supporter
Supporter
Posts: 2992
Joined: Tue Feb 07, 2006 9:11 am
Location: Logan City QLD

Re: Brazilian Teak any good for making a backed longbow?

#5 Post by greybeard » Mon Jun 06, 2016 9:11 pm

Hi Bormin,

Have you tried this timber merchant, they list various decking timbers that may be suitable.

Fastplast Building Supplies
16 Blackbutt Rd Port Macquarie.
(02) 6581 2526

http://www.fastplast.com.au/timber_products

The Balau may be ok with bamboo backing.

Common Name(s): Balau
Scientific Name: Shorea spp.
Distribution: Southeast Asia
Tree Size: 150-200 ft (45-60 m) tall, 3-6 ft (1-2 m) trunk diameter
Average Dried Weight: 53 lbs/ft3 (850 kg/m3)
Specific Gravity (Basic, 12% MC): .69, .85
Janka Hardness: 1,600 lbf (7,120 N)
Modulus of Rupture: 17,730 lbf/in2 (122.3 MPa)
Elastic Modulus: 2,457,000 lbf/in2 (16.95 GPa)
Crushing Strength: 10,280 lbf/in2 (70.9 MPa)
Shrinkage: Radial: 5.5%, Tangential: 10.1%, Volumetric: 15.7%, T/R Ratio: 1.8

Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken.
[Ascham]

“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]

I am old enough to make my own decisions....Just not young enough to remember what I decided!....

Bormin
Posts: 27
Joined: Tue Jan 08, 2013 5:53 pm
Location: Port Macquarie, NSW

Re: Brazilian Teak any good for making a backed longbow?

#6 Post by Bormin » Tue Jun 07, 2016 12:38 pm

Thank you Daryl!
I had no idea they supplied timber, must have driven past them a hundred times.
They're just around the corner from who I get Titebond from :)

cadet
Posts: 62
Joined: Fri Aug 07, 2015 9:14 am
Location: Western Vic and Macedon Ranges

Re: Brazilian Teak any good for making a backed longbow?

#7 Post by cadet » Thu Jun 23, 2016 9:37 am

Hmm: Brazilian Teak/Cumaru: saw a heap of the stuff on sale as reeded decking boards in Masters the other day... Might have to pick through the racks, grab some, and have a play...

Post Reply