wood arrow spine question

[Jon Powell]

I soaked some wooden shafts in Watco Danish Oil and some of them came out very heavy. If I finish making them into arrows the weights will vary from about 600 grains to 700 grains. All the shafts were spined 65-70 before the soak. My question is, will the extra weight affect the spine? To put it another way, will the lighter arrows shoot the same as the heavier arrows in regard to spine, or does the extra weight weaken/strengthen the spine? Hope this makes sense, I'm confusing myself.lol

[snag]

Was your intention to up the weight on these? Obviously the heavier arrows will not have the same arch to the target. I would check the spine on them again.  What is the info on the bow you will be shooting these with?

[Jon Powell]

I wanted a finished arrow around 600 grains. Most of them turned out just right, however 4 of them gained an extra 100 grains. I don't have a spine tester so can't check that. 600 grain arrows spined 65-70 shoot great out of my bow, I just wondered if the extra weight would change the spine or will they still spine and shoot like the 65-70 spined 600 grainers. Except for trajectory of course.
The bow is a Wesley Special 55@28 but I draw 29.5 so I figure it's about 58#. Thanks for your input.

[snag]

Best way to find out, since you have the shafts dipped, is make them up and bareshaft them. But just off the top of my head I would think it would effect the spine. You have more mass being flexed through paradox. If the Wesley is a cut-to-center shelf then it won't be as picky as a bow that is cut to 1/8" for example.

[Jon Powell]

Thanks Snag. It's 1/8" shy of center I believe. I'll just have to do some more shooting I guess. Darn the luck.  

[Orion]

Soaking them doesn't change the static spine, but a heavier arrow does change the dynamic spine.  That is, it will act weaker when shot.  I've soaked a lot of shafts in Wato oil and have never been able to get more than a 75 grain (average) increase with 11/32 shafts.  I expect 100 grains would be entirely probable with23/64 shafts.  I could add 200 grains initially when soaked under pressure, but those shafts continued to bleed for two weeks back down to about a 75 grain gain.  That's why I no longer soak them under pressure.  If you've just taken them out of the soaker, it's likely they'll all loose a little weight before they dry completely.

[Neutron]

I just wipe watco on with a rag rather than soaking.  I saw one fellow posted that he controls shaft weight by soaking in watco and resoaking the ones that come out light.  I am planning to try that with wiping it on to try to get consistent weights.  I am going to try a few light coats so I can hopefully not add too much weight.