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Main Boards => PowWow => Topic started by: ron w on April 15, 2012, 09:49:00 PM

Title: Black Glass.....is it true???
Post by: ron w on April 15, 2012, 09:49:00 PM
I have seen it mentioned on several different posts that Black glass out performs others. I have a Holm-Made River Runner with Black glass that I just love and it shoots well. My new limbs for my Silvertip are being built with Black Glass also. Has anyone done testing to prove this or is it a seat of the pants thing. Is brown or gray glass not as good performers? Or is this just an old wives tale. I'll admit, clear glass with some cool lams is really nice to look at!! I guess I'm just curious!!   :dunno:
Title: Re: Black Glass.....is it true???
Post by: Gen273 on April 15, 2012, 10:10:00 PM
:campfire:
Title: Re: Black Glass.....is it true???
Post by: Pokerdaddy on April 15, 2012, 10:10:00 PM
I have seen Jason "Kanati" Kendall post thoughts along those lines, and he knows alot about bow performance.  Incidentally, my Kanati has black glass and smokes an arrow.  To me, clear glass is beautiful but black just looks all business!
Title: Re: Black Glass.....is it true???
Post by: Night Wing on April 15, 2012, 11:07:00 PM
The way I see it. If the black glass and the clear glass are the same thickness, they should perform the same with regards to arrow speed.
Title: Re: Black Glass.....is it true???
Post by: JamesKerr on April 15, 2012, 11:10:00 PM
I think that in the old days the solid color glasses such as black, brown, Grayling green and others out performed the clear glass. Now a days most high performance bows are made with clear glass. I think the makers of the fiberglass have got it now to where the different glass colors perform the same.
Title: Re: Black Glass.....is it true???
Post by: SlowBowinMO on April 15, 2012, 11:22:00 PM
Yes, it's true.  Has something to do with stiffness to weight ratio or something along those lines I forget exactly now. It's no magic bullet but in otherwise identical bows the black glass will usually be a hair faster.
Title: Re: Black Glass.....is it true???
Post by: Ric O'Shay on April 15, 2012, 11:25:00 PM
I've heard than rumor batted around and around. Don't know for sure if anyone has ever set out to either prove or disprove it. However, Jack Howard tested everything that he used in building his marvelous Jet and Gamemaster bows. If you look at them, if you can get past the beautiful rosewood risers in the Jets, you'll see they were backed with black glass.

Danny
Title: Re: Black Glass.....is it true???
Post by: emt137 on April 15, 2012, 11:33:00 PM
I had talked with one bowyer that mentioned this. He stated the clear glass the "weave" only goes one way. Where as the black, brown, etc glass has a weave that goes two different directions giving it better performing properties. Maybe so; maybe not...
Title: Re: Black Glass.....is it true???
Post by: amar911 on April 16, 2012, 01:38:00 AM
If there is any difference, I would bet the extra speed for the black versus clear would be so small as to be virtually undetectable unless a machine release and an accurate chronograph were used. I say go for what you like, and I personally would not sacrifice the beauty of exotic wood veneers under clear glass for the tiny bit of extra speed that MIGHT POSSIBLY exist with black glass. But there is nothing wrong with black glass, either.

Allan
Title: Re: Black Glass.....is it true???
Post by: smokin joe on April 16, 2012, 03:16:00 AM
I agree with Pokerdaddy. I like the look of black glass -- all business.
Title: Re: Black Glass.....is it true???
Post by: Crooked Stic on April 16, 2012, 06:28:00 AM
Yep black is a bit stiffer. Probably need a chrono to see the difference.
Title: Re: Black Glass.....is it true???
Post by: BigJim on April 16, 2012, 06:41:00 AM
the target guys would notice after long days in the sun, that the darker glass actually would start to loose performance and the lighter glass would not.

There is no weave in the glass, black, brown, clear. It is all uni directional except glass with scrim which is not woven either. Not a performance thing.
Just something else to talk about more than anything. I have always found myself ignoring colored glass in lieu of clear over exotic.

Remember, when you compare,  you must compare two identical bows except the color of the glass. The least difference in design, bow specs, or even shooter is enough to make a bigger difference than any color glass could.

bigjim
Title: Re: Black Glass.....is it true???
Post by: deaddoc4444 on April 16, 2012, 08:57:00 AM
Back in the 80s   SOME of the bowyers then were saying  that GREY  glass was faster than other colors and Green  a close second!      Have older bows with both . Never saw the difference  and don't believe there really was one .   LOVE the looks of both Grey and Green glass  though .
Title: Re: Black Glass.....is it true???
Post by: ron w on April 16, 2012, 08:59:00 AM
Interesting stuff.....I like the colored glass for it's no nonsense look for a hunting bow. I guess it's all in the eye of the archer....LOL! Thanks for the input!!   ron w
Title: Re: Black Glass.....is it true???
Post by: C.Cannon on April 16, 2012, 08:12:00 PM
QuoteOriginally posted by deaddoc4444:
Back in the 80s   SOME of the bowyers then were saying  that GREY  glass was faster than other colors and Green  a close second!      Have older bows with both . Never saw the difference  and don't believe there really was one .   LOVE the looks of both Grey and Green glass  though .
That's what I've heard grey and white were supposed to be the fastest.

To tell you the truth it sounds like the typical "what makes the best bow lamination bamboo, maple, yew or osage" type question everyone has and opinion even the people without one  :D
Title: Re: Black Glass.....is it true???
Post by: koger on April 16, 2012, 08:16:00 PM
David Quinn told me that he once built identical bows, same weight, length, etc, shot them from a shooting machine of sorts, with release, and every time, the black glass was on average, 8fps faster. Remember, David was a mechanical engineer by trade, just got into building bows to make an affordalbe entry level bow that would compete. He also did it more than once, and another buddy or two did the same thing, 6-8 fps faster every time with identical specs. He also stated that he had far fewer issues with black glass, than clear, never mentioned the other colors.
Title: Re: Black Glass.....is it true???
Post by: Outwest on April 16, 2012, 08:20:00 PM
I know one thing.
The old D.H. Hunters with black glass limbs kick butt.

John
Title: Re: Black Glass.....is it true???
Post by: flinthead on April 16, 2012, 08:23:00 PM
Archers with more time and equipment will have to settle this-just know every scratch on black glass shows-clear does not. Roy
Title: Re: Black Glass.....is it true???
Post by: mcgroundstalker on April 16, 2012, 08:25:00 PM
You know what they say, and it's true! "Once you go black, you never go back!"

... mike ...  :D  ...
Title: Re: Black Glass.....is it true???
Post by: Killdeer on April 16, 2012, 08:29:00 PM
It's a great rumor to start if one finds oneself with too much black glass on one's hands, and your clear glass came in all streaky.

Killdeer   :dunno:
Title: Re: Black Glass.....is it true???
Post by: ChuckC on April 16, 2012, 08:36:00 PM
Everybody knows a red Corvette is faster than a black one.

Just saying
ChuckC
Title: Re: Black Glass.....is it true???
Post by: ron w on April 16, 2012, 09:44:00 PM
Well Mike, I was thinking that I wanted just a plain jane hunting bow, and the black glass limbs seemed to fill that need!
Title: Re: Black Glass.....is it true???
Post by: Brock on April 16, 2012, 10:15:00 PM
black glass guys started that rumor when clear became all the rage.....so they would not get stuck with all that colored glass. LOL

i heard every white spot under clear glass is -1 fps...  :)
Title: Re: Black Glass.....is it true???
Post by: sbschindler on April 16, 2012, 10:39:00 PM
Black glass is faster than clear there is no doubt.. the testing was done at the greased lightning labratories, they did the greased lightning tests, they tested regular lightning against greased lightning and found that regular lightning was as everybody knew the speed of light which was 186 thoudand FPS,, and greased lightning tested considerably faster just like the black glass did.
Title: Re: Black Glass.....is it true???
Post by: Lee Robinson . on April 16, 2012, 10:50:00 PM
ASSUMING WE ARE TALKING ABOUT GORDON COMPOSITES FIBERGLASS...

It isn't the COLOR, but the TYPE of glass.

If you are comparing UL (E-glass without scrim) clear to UL black...no difference.

If you are comparing ULS (E-glass with scrim) clear to ULS black...no difference.

HOWEVER...

ULZ glass (S-glass) isn't available in clear, but it does however come in black. ULZ (S-glass) is superior to ULS (E-glass) in compression and tension. I see NO REASON to buy ULS (E-glass) in black. If I want black, I go with ULZ (S-glass). The only reason I get ULS (E-glass) is if I want clear glass.

Here are the stats on this...

 http://www.gordoncomposites.com/products.htm

http://www.youtube.com/watch?v=rvBMPZL94Go&feature=player_embedded
Title: Re: Black Glass.....is it true???
Post by: Ben Maher on April 16, 2012, 11:05:00 PM
black glass may or may not be quicker than clear glass ...

but black glass is plain ol' sexy ...

I had never even see clear glass until the mid 90's .......
Title: Re: Black Glass.....is it true???
Post by: **DONOTDELETE** on April 17, 2012, 12:40:00 AM
The truth of the matter is that different runs of glass has different deflection properties regardless of color.  But... I've noticed black glass on an average is a bit stiffer than clear.

For example: You can build a dozen bows using the exact same thickness glass and core that is typically measured in thousandths of an inch. and lets say  .300 = a 50 pound bow at 28" using clear glass. When these things come out of the form and are profiled, they are typically a little heavy. say 3-5 pounds. that gives you a  little room to sand the glass to balance out the limbs and finish sand it and still hit poundage.

When you lay up a black glass bow at the same thickness the stuff typically comes in a wee bit heavier for me. instead of 3-5 pounds heavy it's 5-8 pounds heavy. sometimes more. So what happens is you have to sand a bit more glass than you did on your clear glass limbs to hit poundage.

So now you have two 50 pound bows and the black glass bow tests out faster every time because there is less glass to core ratio. and wood or foam is lighter than glass.

Now if you adjusted the limb thickness in the core instead of sanding the glass. say .292 instead of .300 They would test out a lot closer to the same.

That's my take on it....
Title: Re: Black Glass.....is it true???
Post by: Sixby on April 17, 2012, 12:49:00 AM
When I build a black glass bow I have to take three lbs of stack out of the core to hit weight. I have noticed that the black glass is much denser when you sand it and that would make it a bit heavier and a bit stiffer. Black S glass is even denser yet and you can really tell the difference when you sand it. Also black glass will go around a much tighter curve without checking wheras clear glass will check unless you taper it.
I agree with Kirk or at least my experience does.

God bless you all, Steve
Title: Re: Black Glass.....is it true???
Post by: Dan Adair on April 17, 2012, 12:57:00 AM
Uh, I got a chronograph and I like to shoot trad bows  :D
Title: Re: Black Glass.....is it true???
Post by: ron w on April 17, 2012, 09:06:00 AM
Wow, a lot of info.....thanks for your input!
Title: Re: Black Glass.....is it true???
Post by: Mike Mecredy on April 17, 2012, 12:03:00 PM
I think one of the reasons Black or Brown Glass may seem a bit faster than those with clear glass, is the bows using colored class have limbs comprised of wood that makes a good limb.  Often times bows made with clear glass will have two veneers that usually are of a wood that is decorative and not exactly a good performing material.  It just adds additional mass and glue to the limb.  When the contrary doesn't use decorative material just good performing material, and only two or more laminations of it instead of 4 or 5 laminations.  That's what I've determined.
Title: Re: Black Glass.....is it true???
Post by: hybridbow hunter on April 17, 2012, 05:30:00 PM
sorry double post
Title: Re: Black Glass.....is it true???
Post by: hybridbow hunter on April 17, 2012, 05:30:00 PM
I guess as the black glass limbs doesn't have any cosmetics venneers they should have a lighter mass and thus give a little fps or 2 faster than the exact same limbs with clear glass over exotic veneers on both side.
Title: Re: Black Glass.....is it true???
Post by: yankeevol on April 17, 2012, 07:45:00 PM
My black glass Toelke Whip (45@28) smokes a 450 grain arrow around 180 fps last time I checked it. I'm REALLY glad Dan decided to make a few black glass bows.
Title: Re: Black Glass.....is it true???
Post by: Mike Mecredy on April 17, 2012, 08:51:00 PM
To clarify, I don't believe it has anything to do with the glass.  If I made two identicle bows, both with walnut limb cores, and one with black and one with clear they would both perform the same.  If I used something sluggish like cocobolo for the the veneers and then walnut cores, it probably wouldn't be as fast as the bow with just black glass and walnut laminations. That .060" of cocobolo would take away performance from the superior walnut.
Title: Re: Black Glass.....is it true???
Post by: Sixby on April 17, 2012, 10:09:00 PM
Opinions may vary!!!!!!


God bless you all, Steve  :campfire:
Title: Re: Black Glass.....is it true???
Post by: pete p on April 18, 2012, 01:32:00 AM
my next bow will have black glass veneers under clear glass just to cover my bases...
Title: Re: Black Glass.....is it true???
Post by: dan d on April 18, 2012, 09:29:00 AM
Interesting post !  I myself am not worried about a few FPS faster, I gave all that talk up years ago when I decided to be a Trad guy    :)  

I am surprised to see all the solid color fiberglass members here, I myself enjoy seeing the wood grain, it just makes it feel more trad to me, like I'm shooting a real stick & string.

Notice I used the word "feel" as I know I'm not pure traditional, yes I use steel broad heads (not stone arrowheads) I don't use traditional sinew string, just thought I better make that disclaimer before I hear your not really shooting traditional so what does it matter. I myself just like the natural wood look and made the observation I was surprised to hear all the folk who love colored fiberglass.

Dan
Title: Re: Black Glass.....is it true???
Post by: Jeff Strubberg on April 18, 2012, 11:18:00 AM
I just like black glass.  It's classic, it's all buisness, it just looks right to me.

Faster?  I bet I could get more performance change outta a 1/4" more draw than going with colored glass over clear.  Just my opinion.
Title: Re: Black Glass.....is it true???
Post by: rustyspike on April 18, 2012, 12:25:00 PM
Just my thoughts. You would really have to talk to the manufacture of the glass to see if there is a differance.

I would think they just add a die for color. On the other hand. Getting clear glass with out streaks my take better control of the maufacturing proecess. Only the people that make it can give you the real answer.

Rich K.
Title: Re: Black Glass.....is it true???
Post by: dsturgissr on April 18, 2012, 01:23:00 PM
A lot of years ago was talking to Paul Schafer about this very thing as I was ordering a new bow. Acording to Paul, you can expect a bit more performance out of a black glass limbed bow.      Denny Sr
Title: Re: Black Glass.....is it true???
Post by: ron w on April 18, 2012, 02:50:00 PM
Since I'm having a set of limbs built ask we speak at the Schafer shop, [with black glass], I guess that's good news....lol! I'm not really a speed is better kind'a guy but it's still neat to hear all the opinions on the topic!
Title: Re: Black Glass.....is it true???
Post by: jhg on April 19, 2012, 12:16:00 PM
I chose black glass because for my tastes

1)many veneers under clear glass are way too fancy, even garish. I never liked super fancy guns either. I do like some veneers, like stained/streaked bamboo.

2)I also bleieve that superior performance is made up by small degrees. These "it won't make a big difference" tweeks added together make a noticble difference. As mentioned, Jack Howard's bows are good examples of this.

Joshua
Title: Re: Black Glass.....is it true???
Post by: Lee Robinson . on July 11, 2012, 05:06:00 PM
My opinions on black glass are based upon my research and experiences. I believe there is a difference in glass. Gordon, the manufacturer of the glass, also states there is a difference.

I make bows with both clear glass or black glass with the same cores...with the only "design difference" being the carbon was next to the black glass on the black glass backed bow, and seperated by a thin lamination on a clear glass bow. Otherwise identical.

That said, I don't think the difference is worth getting excited over...but I do believe it is there.

For this reason, if someone wanted the ULTIMATE bow and cared nothing about cosmetic...I would recommend black S-Glass (ULZ) over carbon then the core, then belly glass. I don't like black glass on the belly myself...so I use clear on the belly in our bows...but if one wanted "ultimate" bow...black glass IMO is the best.
Title: Re: Black Glass.....is it true???
Post by: Glunt on July 11, 2012, 06:12:00 PM
If you like black, and want a few extra fps, I would probably opt for carbon on the back.  I like the look and natural camo of grainy limbs.
Title: Re: Black Glass.....is it true???
Post by: Grizzbear on July 11, 2012, 06:20:00 PM
The color may add some density but not noticable
Title: Re: Black Glass.....is it true???
Post by: sledge on July 11, 2012, 06:37:00 PM
i have done extensive, and if i may say so, absolutely DEFINITIVE testing on this subject.

the 3 fastest glass colors are, in order:

1. pink

2. lavender

3. mauve

i have no idea why they aren't more popular.

joe
Title: Re: Black Glass.....is it true???
Post by: Lee Robinson . on July 12, 2012, 10:11:00 PM
I don't think it is a pigment factor. In other words, I don't think their is any difference between clear ULS and black ULS.

Gordon states the difference is between ULS (E-glass) and ULZ (S-glass). When buying black glass, I never order ULS. I order black only in ULZ. Clear isn't available in ULZ, but "natural" is. Natural however isn't clear...but cloudy. Who wants that? No one...so for me it is either ULS clear E-glass or ULZ black S-glass.

When comparing those two, ULZ is superior. Even though it is stronger and more durable technically, I don't think the difference is worth getting excited over...probably only 1-2 fps difference in efficiency. Both are very durable; however, if one wants the "best performer," ULZ (S-glass) wins.
Title: Re: Black Glass.....is it true???
Post by: Lee Robinson . on July 12, 2012, 10:13:00 PM
http://www.youtube.com/watch?feature=player_embedded&v=rvBMPZL94Go