carbon foam limb core longevity?

[Andy Cooper]

Does anyone know how long the foam lasts before it starts breaking down? Is it a function of time, number of shots, or both? Thanks.

[L. E. Carroll]

I'm really interested in this answer too ??... Great post!    

Gene  

[LongStick64]

Not a scientific answer here but if you buy from people that know how to make them and use top quality products. I would bet they would last as long as any other core wood. Much of the discussion on the longevity of foam cores has come up by Olympic archers that put in more shots than the average trad shooter. Simply siad we don't put in as mileage on the limbs as they do. But if you need a more technical answer, hopefully Bill Dunn or Bob Morrison can answer. Both make fantastic quality Foam core limbs.
As for me I have a pair of Bob Ilf Longbow C/F limbs and used them as hard as any, haven't noticed any loss of performance.

[Orion]

I believe olympic shooters have been shooting foam core limbs for about 20 years.  If there were a problems with the cores breaking down, I think we would have heard of it by now.  

I've been shooting a set of foam core longbow limbs on my Morrison Shawnee for about a year now and really like them.  Smooth and very quick.

[Boomerang]

I think that they should last as long or longer than wood because it is not subject to moisture like wood is.

[McDave]

Generally, we are told that with our fiberglass backed wood bow limbs, we should leave our bow strung if we are shooting it regularly, as leaving the bow strung won't have any adverse effect on the bow limbs.  Do you think the same is true for foam core limbs?

[Stone Knife]

Mine has been strung for a year.

[owlbait]

[Andy Cooper]

Because I wonder about everything about which I know little! Having not had any experience with foam...other than viewing pics...it looks brittle to me. Hence the question.

   

[owlbait]

Wow, you can see brittle in a picture?  :confused:      My foam core looks uniform, smooth, solid. It doesn't look spongy, brittle, springy, soft, uranium enriched. Just looks like a lamination in the core of the limb. Shooting it next to my bamboo core limbs it seems only slightly different, perhaps faster, quieter, and the limb reacts smoothly.

[L. E. Carroll]

My foam core were actually a bit louder than my wood cored limbs.... With a sound different than what I was hearing with wood or bamboo...

I still perfer Bamboo cores but the latest set of Carbon/Actionwood [maple] cored Morrison ILF longbow limbs are the nicest and best performing L/B limbs I have ever owned.  I think when Bob decides to make some carbon limbs with Bamboo cores I'll be looking at a set.  

[684Kevin]

All I can say is that after shooting the Zipper carbon/foam longbow, I dont care if their lifespan was not as long.  I would just have to order another set.  The foam core limbs are really quiet.  They seem to absorb the vibrations after the shot.  I would have to think long and hard before getting another bow without the carbon & foam limbs.

[Andy Cooper]

Originally posted by owlbait:
Wow, you can see brittle in a picture?   :confused:        

Just an impression. I'm considering some foam cores for my next purchase and someone commented to me the other day that they felt like foam would degrade over time.

[Orion]

McDave, I believe I've read that Black Widow has suggested that folks leave their glass backed bows strung because they're of the opinion that folks are more likely to damage the bow in the stringing/unstringing process.  However, I don't think very many builders are recommending it.  Most will say that it won't hurt their bows, but they're not saying they should be kept strung.  Pretty much a personal preference thing, IMO.  I've been unstringing mine for 50 years and plan to continue to do so, foam core or not. I just figure why stress the limbs if you don't have to.  

[owlbait]

I hear you Andy. I refuse to listen to those voices most of the time and depend on my bowyers to give me the straight skinny on what is what. My experience has been good and I am confident that Bill Dunn has the knowledge and integrity to build me the best possible product he can. I think some think of "foam" as soft, styrofoam, easily degradeable material and I don't believe this material meets that definition.

[Longbowz]

In theory foam cores have an unlimited fatigue life.  This is in contrast to any wood lamination.

In reality wood lasts long enough in this kind of application and foam cores along with other composite materials are still going strong in the relatively short time they have been in use with archery equipment.

[Sixby]

I've built foamcore carbon limbs and still do. It is brittle and breaks very easily and it is soft. anyone that has used it knows that. Now that does not mean it is not great core material. In fact the sweetest shooting bows and fastest bows I have built are double carbon foam core limbs. However I will not use it in a recurve because the hooks on my recurve are tight enough that the foam actually breaks.

I believe I may be who Andy was referring to. My comment was that the longevity of wook is established,. foam is not yet. Not in comparison to Bears and Martins ect that have been in use many years and are still good shooters. I do have question whether or not it will degenerate over a long period of time. I have seen plastics and foams degenerate from sunlight and exposure and I believe it is a valid question. However as a core material it is protected.

This is perhaps being nit picky but I sell my bows as heirloom quality bows. I want them to last so when I talk with a customer about a certain bow I tell them the truth about how I feel about it. I love foam core carbon limbs. However I do question whether or not they will last as long as wood core limbs. That is just the truth about whan I think of them,. All that said My hunting bow is a belly mounted foam core double carbon d and r bow.
God bless you all, Steve

[Ben Maher]

Thanks Steve , good honest response from a fella who's opinion i value .

[LongStick64]

Steve makes a great point in that we do not have the same long term testing data with foam that we do have with wood. Either way I still believe that with the application we use these limbs in, if the material would fail we would have had many failures and personally I haven't heard of any. Especially the foam core breaking.

[Whip]

There was a thread that ran awhile ago that had quite a bit of discussion of this topic.  Interesting reading for those that want to know more.  Here is the link.

 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=1;t=092034;p=1