Changing bamboo spine?

[owlbait]

Can I weaken the spine on my bamboo arrows by sanding them down? I have some arrows that are WAY stiff and banging off the riser. Sure is fun when they fly well though!

[H Rhodes]

I don't know about sanding them too much.   I like that tough outer skin to stay in tact as much as I can - it seems to promote durability.  You could try a heavier point weight or cutting them a little longer...  Make sure to have the stiff side to the bow when you are figuring your fletching/nock location.  I like to bareshaft mine to make sure I have that stiff side thing worked out before I fletch.  When the stiff side is away, you can hear them wack the side of the bow when you shoot.  I think bamboo/cane really loves to be an arrow!

[owlbait]

Thanks. I left them long and I can adjust the point weight some. I'll try them cock feather in and see if that helps!

[DarkSoul]

Tonkin bamboo might, just might, accept a bit of sanding to lower the spine a few pounds. But many other bamboo or cane species are thin walled and will drastically lose strength (not just spine) if sanded beyond the outer waxy rind.

You could shift the shafts in the bamboo shoot if the shoot is long enough. The top of the plant is usually thinner (and thus has a lower spine) than the bottom part of the shoot. So if your shaft is still 32" and you need to cut it to 28", your best bet is to cut off the lower four inches.

[owlbait]

Thanks, another great suggestion.

[H Rhodes]

Darksoul gave you something to try.  A friend of mine was making his first cane arrows the other day and had made them with the small end forward.  I had never done them this way and was curious to see how they performed.  Not bad at all!  I think if cut from a section of bamboo that was fairly uniform in taper, like from somewhere closer to the middle of the plant, they could perform really well. 

[Tom Leemans]

I use tonkin cane and I sand the nodes down just enough to smooth them over a bit. They could probably take more, but I don't bother. The spine tester seems to always say that I should be shooting these out of a much heavier bow, but the natural taper compensates for that. What I have found is that the arrows that fly the best will "look" underspined to the untrained eye, but they are plenty stiff enough. I have to use 5/16 nocks if I glue nocks on. I bought 6 ft cane and get the arrow out of the middle. My first batch were way too stiff, so I quickly learned to move down towards the skinny end. I guess my advice is to find the stiff side and shoot them to see what your bow likes. Those really stiff arrows can be used for squirrels or something.

[owlbait]

Thanks Tom. I think that was my biggest mistake, building overspined arrows. But, for my first attempt, I guess they'll do. I shot the arrow in question tonight with the cock feather in, and 100% improvement. Thanks a bunch guys. I appreciate all the help.

[PEARL DRUMS]

Try rotating your nock if you can. Boo can vary greatly as you rotate it slightly.

[JackCrafty]

I've sanded cane shafts to reduce spine and it works well but you have to be careful.  It doesn't take much to change the spine, especially when you sand the middle of the arrow.

The final shaft will be very similar to a shaft made from the skinny end of the cane.  The wall thickness decreases, as well as the diameter, as you move from thick end to skinny end.

Tonkin bamboo is especially forgiving and can be sanded quite a bit.

[owlbait]

Chris, I can't rotate the nocks, I made self nocks! probably the best part of my bamboo arrow build so far!

[knightd]

You can also carefully flex the shaft back and forth to break down some of the fibers and it will weaken the spine..

[crooketarrow]

  Sand them down so what if they break there to stiff for your bow anyway. I sanded them down before just stay away from the nobes.

[agd68]

I was watching a Youtube video on japanese bamboo arrows. The old fellow makes them all by hand the old way. He peeled the rind right off and sanded the nodes down smooth. after he straightened them he kept flexing and sanding the shafts until he was satisfied. Do a search for " making japanese arrows". It's a 3 part series and all in japanese but very interesting to watch.

[crooketarrow]

  I'm no expert on BOO arrows I've only made 11 JAPANESE BOO ARROWS in my life. But I found out the hard way do the straighting before you sand the nodes. You can do it after but you'll break a lot a arrows at the node's. With major bending. At least I did. JAPANESE BOO NODES TAKES SANDING THE NODES BETTER THAN ANY OTHER BOO.