Black Glass.....is it true???

[ChuckC]

Everybody knows a red Corvette is faster than a black one.

Just saying
ChuckC

[ron w]

Well Mike, I was thinking that I wanted just a plain jane hunting bow, and the black glass limbs seemed to fill that need!

[Brock]

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...  

[sbschindler]

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.

[Lee Robinson .]

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

[Ben Maher]

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 .......

[**DONOTDELETE**]

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....

[Sixby]

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

[Dan Adair]

Uh, I got a chronograph and I like to shoot trad bows  :D

[ron w]

Wow, a lot of info.....thanks for your input!

[Mike Mecredy]

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.

[hybridbow hunter]

sorry double post

[hybridbow hunter]

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.

[yankeevol]

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.

[Mike Mecredy]

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.

[Sixby]

Opinions may vary!!!!!!


God bless you all, Steve  

[pete p]

my next bow will have black glass veneers under clear glass just to cover my bases...

[dan d]

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

[Jeff Strubberg]

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.

[rustyspike]

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.