Limb trapping - how to?

[EHK]

I've searched and found a few posts re: limb trapping but I haven't seen any that really explain how to do it.  It seems like most recommend trapping the back of the limb to shed weight, but how far into the limb do you go?  Just into the glass, or into the boo core?  How do you actually remove the material?  (Rasp, files, spindle sander, hand sanding? )
 
I'm working on a glass D/R longbow that's about 9# heavier than what I want.  I doubt I'll be able to get all 9#, but I'll take whatever I can get.  I'm already at 1/2 inch at the limb tips, so I don't want to go any thinner with the limb.

Thanks for any info you can share.

Eric

[macbow]

I've trapped several longbows to the belly side with good results.
But more on here recommend trapping to the back.
Which ever you decide draw a line along the edge of the limb anywhere between 1/16 to 1/8 inch. Draw on all four edges.
The lines allow equal removal.
Using a hand rasp or file will work best, power tools can cause heartache.
You can easily remove 9 pounds.

You would remove from the line to the outer edge of the other side.

[Pat B]

You an also narrow the limbs to reduce weight.

[bjansen]

I generally trap from the back to the belly. After the limb profile is established, and my tip overlays are glued on, I will take a compass and scribe the limb sides on the back of the bow (maybe 1/8"). You can then take the a farriers rasp and remove the material at what ever angle you wish ( for ease, I generally will remove the material from the scribed line all the way to the start of the belly fiberglass).  

I also made a jig which I still use to trap bows  http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=008223

After the material is removed, I will use a sanding stick to make the trapped area flat and smooth, then go to hand sanding to make it final.  Here is the sanding stick  http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=008675


There is some debate about which way to trap is best:  Back to belly proponents will say that it best evens out the tension/compression stregth.  Belly to back proponents will say that trapping back to belly may cause uneeded instability. I agree with both, but I have liked back to belly the best.

[EHK]

Great info.  Thanks again, Brad.