Maple or bamboo on a shorty

[Theolithic71]

I am planning to backwards engineer my '64 K-Mag and tweak a few things on the grip, riser and tips to make it my own.

For a bow this short (52Amo) what would be the benefits of cores made of bamboo versus maple or vise versa?

I've never used bamboo before so I have nothing to compare to maple.

Thanks,

Ted

[Flem]

This is an opinion based on no knowledge of takedown limb making, Maple.

[Mad Max]

I have a piece of Vertical Grain Maple I have used many times over the years, plenty dry
When I cut lams from it, the next day they want to turn left or right (maybe a 1/8"), Not a big deal because they are 2" wide and cut down to size.
Vertical boo flooring stay's straight, other than that boo flooring may be a bit better.

I don't think core wood make a difference on recurve because there stack is thinner that a R/D or Long bow, could be good for a Hill style. my 2 cent

[4 point]

I feel maple is more stabile in a recurve. Just my opinion, could be all in my head but a boo limb in my design of recurve seems easily twisted

[Theolithic71]

Looks like maple then.

As I look at Bears bow lineup, every one uses maple cores.  You'd think that as readily available as bamboo is globally that companies that manufacture mass quantities would use it.  There must be a reason NOT to use bamboo and to choose maple instead.  I'd like to figure out the reason.

[Mad Max]

Bamboo flooring was real popular years back and you could get it at Home depot and lowes, they don't carry it anymore, you could order it on line and pick it up at the store with no shipping charge. $70.00 a box
Now the price to ship it (a box 24.12 sq.ft.) is as much as the flooring.
I have looked online and can't find it local to pick up any where.

Yes you can buy lams from several bowyers.
I still have some but will be going to maple when it runs out.

Google this
Vertical Toast 5/8 in. Thick x 5 in. wide x 35-5/8 in.  Model# 205124740
Out of stock every where I  look.

[Crooked Stic]

Big Jim has the quality bamboo planks that he uses in his bows for sale. If you can meet him at a shoot in the summer and save shipping.

[Theolithic71]

I usually go to two shoots.   Comptons and Tennessee Classic.  Jim goes to both.

[Flem]

Looks like maple then.

As I look at Bears bow lineup, every one uses maple cores.  You'd think that as readily available as bamboo is globally that companies that manufacture mass quantities would use it.  There must be a reason NOT to use bamboo and to choose maple instead.  I'd like to figure out the reason.

Maple is probably the most underrated lam wood. It's not at all exotic or colorful. It is, good mechanical wood, inexpensive and home grown. I'll bet it requires a lot less processing than Bamboo to get a useful lamination.

[Sant-Ravenhill]

In Traditional Bowyers Encyclopedia Fred Anderson (Cascade Mountain Archery) said this, " Maple is an outstanding corewood. Many bowmakers, especially longbow builders, don't understand the mechanical properties of maple and how wonderful it really is. You can pre-stress maple and use it edge grain or flat grain. It's wonderfully light and strong, and it has a high modulus of elasticity. Plus it's tough and glues well."

"It lasts longer than most woods so you can plan on getting a lot of shots out of it. It has a few minor drawbacks but there isn't a wood that doesn't. A lot of people write off maple as a bow core. But what corewoods have they used to set all the flight records? And what corewoods have won the Olympics? They're all maple cored bows and theres a reason for it. When I hear someone downgrading maple as a core, I know they haven't made too many bows and they sure didn't make any high stress recurves that had to stay together."

There is still much truth to this even 34 years later.

[Mad Max]

Well said Sant

 

[Theolithic71]

I had this golden eagle bow in the 80's.  The limbs used a vertically laminated maple core arranged just like the bamboo flooring.

[Longcruise]

I had this golden eagle bow in the 80's.  The limbs used a vertically laminated maple core arranged just like the bamboo flooring.

That would be action wood I believe.   Kenny can comment with more knowledge on the subject. 

I think Border uses it in most of their bows.

[Mad Max]

You use vertical grain Maple (riff sawn) for lams
Vertical, what ever you want to call it

[kennym]

The Rutland actionwood was maple I think, what you get now is yellow birch . Maybe not quite as good as the maple but no way to test.

I do have a little piece of shop built actionwood I made a few years ago for the bow swap. All tapers with maple to the butt of Lams for strength and  walnut to tips for light weight. Guy told me it was his fastest bow(Shreddy take notice), but PITA to make.

[Arlo]

When you hear some bowyers say “cores don’t matter” , that tells you he hasn’t spent any time really testing his bows accurately, or hasn’t  built very many laminated bows….. he will see there IS a difference in time.

Rock hard maple is very hard to beat for longevity and consistency from one bow to the next. It has very nice compression strength.

 Action boo is also a very nice lamination, but it’s really hard to find good laminated vertical grain flooring any more. Bamboo actually exceeds the tensile strength of rock hard maple, but it has very poor compression values. So using bamboo in a recurve design on the belly side of the limb can be an issue for longevity.    The perfect combo is bamboo back, and maple on the belly side of your core. IMO

Years ago I built my own action wood from maple and walnut for a recurve core and it was really fast. But time spent on labor and materials laying up action wood is not cost effective at all.

For good longevity and consistency…. Rock hard maple is hard to beat.

Years ago elm was very popular for core material, and I’ll bet some bowyers still swear by it. I wasn’t impressed myself as the wood is so much softer than hard maple. I  got better performance with maple too.

[Theolithic71]

So, when building the "action wood", doe thus mean taking flat sawn grain, rotating it 90 degrees and gluing it up to make quarterly sawn grain?  Is that the idea/benefit, or is there another benefit to laminating this way?

[Longcruise]

  Years ago elm was very popular for core material, and I’ll bet some bowyers still swear by it. I wasn’t impressed myself as the wood is so much softer than hard maple.

I built an ASL with all elm cores.  Even an elm riser.  Under clear glass it was blah appearance wise.  I did a krylon job on it
  It was fine in the performance department.  That was my one and only ever departure from maple cores.