BP glass

[Crooked Stic]

This is on another forum. Dont know if it has been talked about here.



Re: Bear Paw glass changing spine?
« Reply #13 on: Today at 05:26:03 AM »
Quote
I had a long conversation with Toby at Black Widow the other day. Seems I’m not alone with the hitting weight challenge with the Bear Paw glass. He said they have more stock bows than they have ever had because of missing weight. Later that same day, Tim from Kustom King called me and talked to me about the issues I was having. He’d already spoken with Toby and was going to be in touch with BP in Germany later that same day. They seem committed to resolving/figuring out what is creating the problem. Even being aware of the problem, I’m still going to continue to use it. I’d rather have a pair of limbs that I missed weight on than a pair of limbs that is covered by streaky glass. I’d urge guys when switching from one roll to another to have glue up a test set of limbs with the same species of veneer, same thickness and same core to compare to an older glue up so you can adjust the stack if needed before you go gluing up any once in a lifetime veneers. On this latest roll I opened up a couple of weeks ago, I had to add .015” to my stack to bring the weight up. They came in 7 pounds light. Frustrating, but I love how clear their product is.

[Crooked Stic]

One guy is clamping it 12 or 14 in. and hanging a clamp type paper clip on it just to compare the spine. That just tells you if it is the same or weaker.

[T Folts]

I was in on the conversation on the other sight as I missed weight on a bow after switching to Bear Paw glass.
I ended up making a second set of takedown limbs and hit weight a little high but workable. I made up a jig similar to what mike posted and started comparing glass. I see a 7/8" deflection from Gordons to Bearpaw. BP glass has a bigger deflection. (weaker). I also compared black glass to clear (Gordons) with the exact same number. I have more BP coming so I will compare that to what I have.
With this new info I am wondering if there has been a difference with the Gordons all along but less and a contributing factor in missed weights.
Terry

[Crooked Stic]

I would think with BP getting big guys like Black Widow as customers that they will want to resolve this issue.

[Crittergetter]

I just gave BP another try.
Clarity is great but even after adjusting the stack To compensate for it I still came in a few pounds under where I wanted to be before trapping and rounding edges. I could only do a minimal amount of rounding to stay within target weight.

[kennym]

Did a little mod on my arrow spine tester. Getting some results ...


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[kennym]

Results aren’t consistent enough to suit me , still workin in it , but I gotta go huntin here in a bit. Two weeks of season is all that’s left!!

[Crooked Stic]

I think You would have to also have to check the particular piece for a very accurate grid also before the spine test. And still only telling you the weak and strong piece. And guessing how much to adjust stacks untill you have glued one up.

[Bow man]

Henry and Tim are both supposed to be at Kalamazoo booth stop and let them know if you are having problems.

[kennym]

I haven't had any probs except a bit lighter weight than Gordon's. Love the clarity of it !! I've heard some are having probs with weight differences between rolls and was just looking to learn something with the spine testing(which I haven't yet...)

[fujimo]

so my question is, with the BP glass showing a  "weaker spine" according to what i see from posts above- and am i correct to  assume that it might have less actual glass in the matrix, and more resin- which might have something to do with the increased clarity- being that the glass is thoroughly and properly saturated.
In any Fiberglass layup, the actual strength comes from the saturated glass in the layup, and the more glass, the stiffer and stronger it will be.

in the Gordons glass, those dry streaks are not fully saturated glass.
 and  not fully saturated glass is not a good thing either.

i may be splitting hairs here, and maybe the glass( my guess) is so over engineered on both of the  products anyway, and that these issues are pretty minor in the bigger scope of things.

[Tim Finley]

Do you mike in several spots the length of the strips ?

[Holm-Made]

I understand that Bear Paw has more fiberglass and less resin then Gordons.

[Crooked Stic]

i do know for a fact, speaking to quite a few of my friends in Europe, that just because BP guarantee their bows , does not mean they dont break- and i have heard quite a bit of mumbling lately about folks' warranties not being honored.
i build my own bows , so this does not effect me- but just an observation.

Did you get this from a reliable source.

[trasher]

Sorry, that is not a fact it is just an observation as Fujimo wrote
Guys, I'm not a friend of bearpaw products, this has nothing to do with their quality,
but I don't know any bowyer who's that accommodating.
I know a lot of guys who got their bows replaced in a short time without any problem.
Including a friend which bought a 4 Year old secondhand bow without any invoice. The bow broke, he called Bearpaw and 2 Weeks later he got a new one!
Henry's service is realy great!
I did not hear this from someone, I experienced it first hand.
Another Bearpaw story.
 I ordered 12 Goldtip-traditional shafts years ago.
The delivered nocks where horrible, 60% of those nocks broke  after hitting hard.
I called Bearpaw.
They told me that  a charge of nocks had a wrong mixing ratio, so they send me 50 pieces for free.
I know nocks are not expensive but I realy appreciate it.
But there are also a lot of people who want to take advantage of this.
If bearpaw get aware of this, you will get what you begging for......

[Crooked Stic]

I was hoping to hear that he does stand behind what he says. My thinking is if it is not fact and just hear say then dont post it. I would think with Henry taking on the Shrew line he will be a great guy to deal with because Ron is a stand up guy.

[fujimo]

sincere apologies to all, i have retracted, and edited my post.
i will most certainly refrain from getting into a mud slinging match with good folk on this site.
its probably the oldest unspoken rule on these public forums; that if one has an issue, take it up with the right folk first, dont drag things to an open and public forum.
i was wrong in doing what i did.
once again sincere apologies.

[Mike Mecredy]

Well, here's what I discovered this week.  I made 3 bows, all 57" D/R design off the same form, all are .334 thick at the fades, and 1 1/8" wide, all have 15" risers,  all I used bear paw glass from rosewood shop.  One of them I used the new crystal clear glass.  The one I used the crystal clear glass on was 7.5# lighter at 27".  The other two I used bear paw black.  The clear glass one had black limba cores, and the black bglass ones I used hard maple cores.  Weird... discuss...

[Bvas]

Mike, do you have more of the glass where you could do some sort of impromptu flex test to compare the black and clear?

I know a lot of guys say that changing core wood doesn’t effect much, but could the softer limba cause the difference?

[Mike Mecredy]

I don't have any more of the bear paw glass, but if seems as only the clear give me results different for the gordon's glass I usually use.  The black glass gave me the results I was expecting.  The black limba in the clear glass I would expect be a pound or two less in draw weight than using maple as laminations but it wouldn't be nearly 8# less.  Even the difference between wood cores and bamboo isn't much more than 2-3 pound of bows of the same design and stack thickness.   

It sure is nice and clear though, I've just written all th results down in my notes to make sure I make the limbs a bit thicker (I guess around .005" thicker to make up the difference.

Tomorrow when I test the three out, I'll mention if the clear glass performs any different than the two with black glass.