Iwant to try and make some poplar shafts.I need 85-90# spine,32'' arrow.Can I get this from poplar and if I use a block how much do they reduce spine?
pinecrest, I would think a compression block would INCREASE spine, not decrease it.
The 3rivers catalog says it decreases spine.
try it and see...
i would agree that compressing should INCREASE spine and if i remember correctly there used to be an arrow called the 'forgewood' that was compressed and they were very stiff spined.
maybe the use of heat is the determining factor.
Anybody that I've ever talked to that has used the compression block has reported a LOSS is spine. I know it sounds backwards. About 6 lbs on a POC from 11/32 to 5/16 is what I remember. Search some archived threads. Might find more there. I've used some 3/8 Poplar dowels and many of them spined in the 90+ range so you shouldn't have much problem finding that heavy of a spine in them, but your going to have to run some thru the compression block to find out exactly how much they will loose. dino
I lost from 3 to 5 pounds on cedar, going from 11/32 to 5/16.
You are both altering (crushing) the outer wood as well as reducing diameter, both of which affect strength negatively, which reduces spine.
I think I''ll skip the block and leave them 3/8 as I need the spine.Thanks for the input.
Then it must not really compress the shaft..the only compressed shafts I ever used were true Bill Sweetland forgewoods....and they were made smaller and denser by compression..and increased in spine and dropped in diameter, significantly.
It must the the lack of heat- and the compression block must only be like "boning" a baseball bat...it just hardens the skin..rather than compressing the shaft?
Ray:
Your talking about apples and oranges. The sweetland shafts were truly compressed. The growth rings were compressed "BEFORE" the wood was doweled. the "Compression block" is nothing more that a highly burnished shaft. Does it reduce its diameter, yes but its not compressed in the true since of the word. Only a small portion of the shaft's outer surface is compressed.
Bob
Spine goes up by the cube of the diameter so a tiny decrease in diameter makes a huge decrease in spine no matter the material. Bob's right, forgewoods can be high spine for their diameter but larger diameter forgewoods are stiffer still....O.L.
Right, as I suspected, its nothing more than when you 'bone' a newly made baseball bat to harden the exterior skin of the wood...no real compression except cosmetic.
I was wondering if there'd be a run on compression blocks from 3Rivers after the last TBM :)
The Veritas 3/8" dowel cutter does work very well, but I'd recommend sawing your blanks oversize by at least a 1/16" of an inch, especially if you're doweling doug fir, pine, or poplar. You'll get a much cleaner cut. Veritas actually recommends a 1/2" blank.