.020 carbon back, .043 glass belly OK?

[limbcracker]

I'm about ready to glue up my first glass, wood core bow, I bought a .020 carbon fiber strip for backing with a .043 glass strip for the belly. I'm wondering if that thin a carbon fiber will hold up in tension against the thicker glass in compression?  More details if you need them: The middle will be a .120 tapered cherry lam under the clear glass on the belly and a parallel maple .150 This will be a straight longbow 62" , 12 inch handle, limbs deflexed 4" in the for. The glass is gordons, using smooth on, form, heatbox etc. I'm shooting for @ 50 lbs at 28"

[limbcracker]

Oops, I meant the bow is reflexed 4" in the form.

[Robertfishes]

limb, I have a similar 50 lb long bow to build in the near future. I was planning on using  a thin piece of black fiberglass over the carbon, I think I am going to sand the back glass down to .025 and use .040 black glass (no carbon) on the belly, considering using hard maple as the taper and parallel. I need to do some more research too..

[bjansen]

I just glued up a bow last night, carbon back, glass belly.  

I used the followign back to front:

.030 carbon (sanded one side from Binghams)
.030 white core glass
.110 maple S/A taper
.060 Shedua
.110 maple S/A taper
.030 white core glass
.030 black fiberglass

I think it it going to hold up fine, but will deliver a report.  I think the issue with the carbon is it is somewhat brittle/fragile compared to fiberglass, but is clearly better in compression/tension. I was planning to put a snakeskin on the back of this one.

[limbcracker]

I glued up my bow with the lambs described above. 4" deflex, then tapered the last 12 inches to 1/2tips, put it on the tillering stick and tested the weight, it was pulling over 70lbs before I got to brace height. I cut it pyramid tapered from the fades to the limbs, It tillered to over 65lbs, so I kept grinding the sides until I got to my desired 50lbs at 28" with 3/8 tips. It shoots a 510 grain arrow @ 170fps and more importantly, right were I aim it, put the first three arrows our of it in my deer target at 20 yards. If i was doing it again I would only use . 20 glass on the belly instead of .043.

[limbcracker]

Fishes, some research I have done on caron - A bowyer I know fould that its not good in commpression, on the belly, glass is better, but good on backing. Also O L adcock uses carbon on the backs of his bows, on the outside, and says it works best on the outside, My bow has the carbon back on the outside, shooting fast flight string it seems to be fine, but I've only put about a 100 arrows over it. Once I get it finished and put the snake skin on the back I'll try to post a pic. Oops, once again I wrote deflect in the post above when I meant reflex. Good luck on your bow.

[bjansen]

I worked on my carbon backed bow last night.  I am not a huge fan of working with this stuff.  It is very easy to pull up a splinter on the back and the fine carbon dust is terrible.  I have one more strip of this at home and I think next time I will follow Bingham's recomendation to use it as the first core lamination inside the fiberglass backing. The bow is looking darn good though!..I added white glass and deer antler tip overlays last night.