Bamboo Backing (Thickness)

[RT]

Hi, would like to get some advise if I was using a boo backing of 5mm in thickness and a tropical hard wood,
would that boo backing of 5mm over over power the core wood causing it to crystalise?

RT

[knightd]

What tropical hard wood are you planning on using??

[RT]

Iron wood or Black plam found in Asia..........

Additionally, I would like to know if bowyers out there have come accross problems when they prepare the boo a little thicker than 3.5 mm, this has caused the core wood to crystalise?

Or best option is to stay with Boo backing of 3.2 mm and less. Thanks!

[nickf]

I never bothered trying to get them paperthin. 3-5mm usually. Doesn't matter that much. Give it a try!

Nick

[burn em up chuck]

 cut the shape of the bow (bamboo) you want, and make all exposed edges on bamboo 3 to 5mm the belly of bamboo very flat. most tropical hardwoods can take it.

                                                                                      chuck

[Kent D.]

Depending on the wood, the thickness can be different.  I know some who like to use a thick bamboo on dense wood and thin on less dense wood.    A thickness ive found that works pretty well with lots of different woods is;  1/8" at the middle and tapper to  1/16" at the tips.  I use this thickness with Ipe, Osage, hickory, and black walnut.  I know some guy who cut out the design of their bow on the bamboo and then just flatten it to a knives edge all around.  Ive never done it that way, but ive seen some good bows made with knife edged bambool.

[Bowmonk]

The important qualities of bamboo in a piece of backing is limited to tension... and only a thin outside portion of the cane is actually going to do the work. Although there is nothing wrong with a "little" extra of the softer wood on the inside of the cane, the problems you will run into if it is too much will be a shift of the glue line, and many times i have seen where a person has whittled away their belly wood in an attempt to lighten or perfect a tiller, only to whittle away too much suddenly and pass the point of no return for the desired draw weight.

Always, Always... attempt to make the bamboo backing as close to 1/16" of thickness at your finished edges. In order to do this you should already have the belly blank profiled... then trace the profile to the flat back of your bamboo... then trim the profile and continue to thin the backing until the edges are about 1/16" this is enough for backing... and will safeguard you from having a backing that will overpower the belly.

Another little trick to having nice glue lines...  use a concave scraper throughout the length of the backing on the glue side... taking care not to remove any from the outside edges which you worked so hard at making flat.  this will tend to trap more glue and prevent dry joints... will also keep the edges tight to the belly core making finer glue lines... and will allow for some surface expansion on the back due to the moisture of glue absorption.

Have fun