HH bug got me ... Part One!

Rob DiStefano · February 11, 2011, 11:03:00 AM

heat tempering bamboo/cane ("caramelizing") always increases stiffness, compression and durability.

as an example, if 2 tembos were built to the precise same spex, but one had the boo heat tempered to the point of changing the pith color (and molecular composition), the heat tempered limbed bow will be higher in draw weight.

Montauks · February 11, 2011, 11:14:00 AM

For what it's worth i'm pretty sure all the bamboo in hill bows is "Tempered" is caramelizing just taking it further or a different process?

Rob DiStefano · February 11, 2011, 11:20:00 AM

QuoteOriginally posted by Montauks:
For what it's worth i'm pretty sure all the bamboo in hill bows is "Tempered" is caramelizing just taking it further or a different process?

yes.

canopyboy · February 11, 2011, 11:27:00 AM

I read a great scientific paper on heat treating bamboo. Titled "Bamboo in the Laboratory" by Wolfram Schott. I'm an engineer and this helped me put my hands around all the anecdotal evidence out there. Google it, it should still be available as a .pdf.

The stuff was centered on fly rods, but it really came down to drying out the bamboo if I remember. Air drying gets rid of most of the free water, or water within the cells. But there is also water tied up in the cellular walls and tissues themselves that don't really leave until heated to higher temperatures. And when the water leaves these trapped areas, it doesn't come back even in a humid environment. This is where the real effect of heat treating is seen.

I think that it is also the same mechanism for heat treating other woods as well. The trick is to get drive it to the optimum point before the tissues actually start to break down (then it's a little too dark.)

canopyboy · February 11, 2011, 11:28:00 AM

Carmelizing is the same process as tempering. It just heats it a little further, darkening the wood and driving out more of the trapped moisture.

Rob DiStefano · February 11, 2011, 11:31:00 AM

i 'heat temper' bamboo to the point of 'caramelizing' - this bubbles the resin, changes the molecular structure, and can color the boo from light tan to chocolate brown, depending on how much heat and how long.

David Mitchell · February 11, 2011, 11:40:00 AM

pavan, that's the problem I have seen before with speed comparisons. A guy may be perfectly happy with a bow until he gets a number in his mind! Then can't get over that number. I read a comment by Dick Robertson a few years ago--he had made a self bow and was really shooting it well and planned to hunt with it that fall....until he decided to shoot it through a chrony. He was surprised and disappointed in the "performance" and hung the bow up for a while until he thought it over. He decided not to let a number stop him from using the bow he had previously been completely happy with. I think there is something there we need to think about. I am a little concerned with the increasing interest in speed in traditonal circles. Just my thoughts.

Montauks · February 11, 2011, 12:18:00 PM

Dave I think I found it HERE probably more than anyone would want to know..lol

canopyboy · February 11, 2011, 12:24:00 PM

I'm never sure of the rules for posting links, so I generally don't. But yeah, you found it.

If you don't want to try to digest 29 pages of technical mumbo-jumbo, aim for the conclusions on page 20.

WESTBROOK · February 11, 2011, 12:42:00 PM

Rob said it best

Quotewhat does all that mean? probably squat.

If speed is your game you should probably back up to square 1 and pick a different style of bow.

Other than that, enjoy them for what they are.

Eric

SpankyNeal · February 11, 2011, 01:00:00 PM

All you need is enough to give sufficient penetration, with a hunting weight arrow, to cleanly harvest your intended quary...anything more than that is just extra dirt on your arrows!

Montauks · February 11, 2011, 01:13:00 PM

Don't get me wrong i'm not interested in speed numbers i was just curious as to what "tempered bamboo" means I think if we were all obsessed about speed pertaining to an arrow we would be shooting the compound arrow launching devices

Wannabe1 · February 11, 2011, 01:20:00 PM

I like to watch the flight of my arrow! :D

canopyboy · February 11, 2011, 01:24:00 PM

The refresh rate on my eyes is a bit slow. About the only time I really get to watch the flight of the arrow is when I throw it....

Wannabe1 · February 11, 2011, 01:30:00 PM

My Tembo was fast enough yesterday that this one didn't get out of the way!

15yds and all most got my first Robin Hood.

Montauks · February 11, 2011, 01:31:00 PM

QuoteI like to watch the flight of my arrow!

Me too especially in archery golf, point the arra high and let er fly!

Ben Maher · February 11, 2011, 04:38:00 PM

Rob Said ...

Quoteanyone have a t/d sleeve craig hill longbow???

looking to get the length of the separated limbset, versus the connected length.

Not sure how you mean Rob But I'll measure mine up this arvo for you .

Rob DiStefano · February 11, 2011, 04:41:00 PM

QuoteOriginally posted by Ben Maher:
Rob Said ...

Quoteanyone have a t/d sleeve craig hill longbow???

looking to get the length of the separated limbset, versus the connected length.
Not sure how you mean Rob But I'll measure mine up this arvo for you . [/b]

thanx ben - need to know bow length, then separate the limbs and measure each limb from end to end. need to get a feel for how long it is broken down for air travel.

leatherneck · February 11, 2011, 04:44:00 PM

Rob, longbowben has one. I know the bow length is 64". When he gets home from work I'm sure he'll see this and measure it for you.

MikeM · February 11, 2011, 05:09:00 PM

Rob I have 70" Hill take-downs. The upper limb includes the sleeve and is 39" the lower limb slips into the sleeve and is 35"