Does urethane add spine to shafts??

[kenner]

Hi all,
  I will one day do the test on this, myself, and post the results,, but... Does urethane stiffen a wooden arrow shaft,, and each coat actually add more spine???  I'm working with Hildebrand's spruce and Surewood fir shafts.

  I've made my own high-tech, precise, spine tester, with a dial-depth-gauge,, so I respectfully don't want opinions, unless you have lots of experience, or data to back it up.

  Thanks!!....  Ken

[Stumpkiller]

I have never noticed a difference between when I spine a raw shaft vs. a polyurethaned shaft.  But I go for five-pound ranges so I'm probably outside the box for any change it might create.  I also wipe it on (three coats) and so it's a thin layer vs. any appreciable build up multiple dippings might add.

No opinion - just not a noticable change if any.

[Grey Taylor]

Originally posted by kenner:
I've made my own high-tech, precise, spine tester, with a dial-depth-gauge,, so I respectfully don't want opinions, unless you have lots of experience, or data to back it up.

I think you're handicapping your search for answers.
I'd be very surprised if too many guys here have made in depth testing on this issue to collect a pile of data.
Besides, if you've already made your own "high-tech, precise, spine tester" why don't you do the testing yourself?

Guy

[Raging Water]

Boy, you would think the more the urethane the more the weight GR per pounds and it would also stiffen the spine. But, it may be marginal.

You are right, you just need to test it.

I would love to know the results. Please, keep us informed.

Matt

[deaddoc4444]

I have used a lot of different types of finishes  Including Spar varnish  It seems to add weight but never noticed spine changes.    
  I have finished arrows with up to 5 coats of spar varnish and added 20 grains of weight but they shot the same.

[distantbear]

After many years and making thousands of arrows I would say no!

[Stumpkiller]

Originally posted by kenner:
I've made my own high-tech, precise, spine tester, with a dial-depth-gauge,, so I respectfully don't want opinions . . .

As a PS - I have a low-tech, unsophisticated spine tester with a cardboard gauge measuring shafts with a 10 grain +/- weight variance.

   

It's not like I'm looking for one hole groups at 100 yards. We're talking about measuring wood  here.  If I was anal I'd shoot carbon.    

[Zradix]

That's funny!

[magnus]

No I have done anywhere from 3-6 coats of poly urethane and yes it adds weight but never saw a gain in spine. I did check between coats on several occasion's.

[tecum-tha]

A dial depth gauge is no better than the dial indicator if done right. All you measure is deflection. Your goal is to minimize friction in the dial indicator, so wood is definetely not the first choice as a mechanism material. Stiff metal rods and a correct scale for the geometrie of your tester setup is much more important.
Another important factor is magnification scale. I magnified my scale by 1.5 times to get better reading in stiffer spien groups. And the finish will not add any stiffness to the shaft, because by adding weight it would lessen dynamic spine. Both effect equal out each other.

[kenner]

Thank you all for your input!

Why do it?.... It feeds my obsessive-compulsive need.  Nothing more beautiful than watching those arrows loft their way to the target, like a torpedo, and then, stick perfectly straight.

Every 1/4" of shaft, two-three twists of the string, 5-10 grains of point weight changes things ever-so slightly.. even with carbon and aluminum.

It's a lot of fun, making fine furniture that flies well.

[Grey Taylor]

To each their own. But two or three twists of the string? If I had that level of obsessive compulsive I'd be looking for some therapy.

One of the big attractions for traditional archery is its simplicity.

But if it makes you happy, more power to you.

Guy

[jarhead_hunter]

If you wanna do this correctly spine and weigh the shafts before the urethane is applied.

Then both check the spine and weight of the shafts after it is applied.

Make up 3 arrows of each group to the same specs.

Shoot them and record observations.

Charles.

[PEARL DRUMS]

I always get a kick out of these "hair splitter" threads! I shoot bows from the side of a tree with bamboo arrows and they fly like darts and hit just what I want.......even with varying poly thickness per my micrometers......................... Just poking fun guys! Take all the OCD you have and focus it on practicing with what you do have. You will be a better archer as a result.

[kenner]

Yep Charles, spot on.  

I'm a retiring science teacher and so, I appreciate your systematic approach, as with the others, who have offered objective advice.

(this comment is not aimed at those who offered advice on precise methods).....
If you don't have experience with urethane and/or wooden shafts, or scientific methodology, please don't post.

I've been shooting since '60 and burnin' feathers and fletching and spinning strings since '66....  This is just ultra-fine tuning... I'm not satisfied with whatever gets 'er done.

I'm sorry if I may have disturbed those who are happy with their gear.  Whether it be archery, or fly fishing, or cooking, I've always asked, "what if I...."... and as Frost said, "that has made all the difference".

Charles:  I noticed the dates on your post.... Crazy times!.. Thank you for your service!!  I was too young to be there, but I do remember the nightly news and the turmoil in America during those times.

Again, thank you, Charles,, and any of you who were there for us.

[Zradix]

Maybe archery is his therapy.

I know I get a little obsessed about this stuff.
aka..foc..4-4.5" modded t-hawk feathers= 13% more feather that 3-5" shields...etc.

You gotta love this stuff.
You can go as far as you want with it.

if good enough suits ya ..COOL!
if you want to spend 4 days figuring out how to get .0001% better whatever...COOL!


   

[kenner]

The arrow's flight reflects the archer.  When I'm scattered,, so are my arrows.... And as we focus, so fly our arrows.

It can be a meditation/ or a study in anxiety.  The arrow's mark is the culmination of who we are at that exact moment....

Ever had the feeling/explanation:  The arrow "shot itself"?... I didn't release; "it" happened...

Like with anything.... Archery can be your meditation,, and an understanding of your psyche.

Good flights to you all!... Ken

[Zradix]

Kenner,

I'd like to welcome you to the gang.

I'd also like to give you a little friendly advice....
This site is one where people treat others as friends and equals till proven otherwise. To start right out with your first posts asking non-techies to stay away is sort of against the grain here.

My first few posts here were against the spirit here too. I caught on though and have learned how great this site is.

On another note, spar urethane is softer than many of the other types of clear used on arrows.
Quite a few people have complained about target burn when using spar.

happy experimenting!

[Zradix]

If you are doing this project just for the fun of it that's cool. I'd be interested in what you find out.

If you are interested in this because you're wondering what spine arrow to buy that's another thing.

I had two arrows that were within one pound spine of each other. I shot one of them in the raw, steel wooled smooth and fletched. The other was sealed with wipe on poly urethane and fletched. Both were spine tested in the raw.
I couldn't tell any difference in flight.

[kenner]

I'm looking for the perfect match for my bow and then, I'll fletch 'em up.  This includes tuning with my Stos broadhead.

My bow shoots 15# over listed poundage.  Add to that a light-wt. string, wrapped nock pt., 1/2"over 28", and 10-15 grains over 125 standard,, and now we're talking another 3-5#.

All set-ups shoot differently.

I know that any arrow will come off a string... and given enough fletch, it's all good.

Not sure what to make of the opposition for the quest for as near perfect flight as possible??