How fragile are carbon fibre tubes?

[richarddownunder]

Hi all

I have just re-read a review on the Orion Optics CT10L from Sky at Night Mag, Sept, 2009, which gives the scope a glowing report. However, it made a comment "the exposed edge of the open end will need care when handling", which I take as a warning that it's fragile. I gather carbon fibre is rigid but can be quite brittle (depending on how its used).

Just wondered if anyone would care to comment on the practicality of CF versus metal (is the main reason for selecting it related to its thermal properties (and maybe aesthetics)? Is it practical for a Newt that will be hauled around the place?

Thanks

Richard

[laser_jock99]

The Hubble Space Telescope is largely a carbon fibre frame.

[ecosse]

If its genuine carbon fibre then it won't be fragile! It will only be expensive

[rowan46]

It's only the exposed bits at the ends which are fragile cf itself is a very strong composite which is why it's used for bikes and f1 where lightness and strength are useful attributes. If the ends are finished properly there should be no problems and should be able to take the same sort of knocks that steel does it is however expensive although costs are coming down.

[UnderTheRain]

It's not fragile it's more likely to he sharp hence the handle with care the cf will cool faster and generally be more thermally stable not to mention lighter

[richarddownunder]

The Hubble Space Telescope is largely a carbon fibre frame.

Yes, but I'm not so likely to stuff that into the back seat of the car!

Thanks for all your replies. I was just interested whether it would be more prone to cracking at the ends. Sounds like it does have some advantages.

[Caelus]

Backing up the comments here, carbon fibre is extremely strong - my experience with it is through archery. A great many arrow shafts are sheathed in carbon to improve the stiffness of the arrows for use in high-powered bows. If they can survive the sudden thrust when shot from a bow and rapid deceleration when they strike a target (both cause a lot of flex), you'll be fine with it on your telescope.

Just be careful you don't damage any exposed ends, as carbon fibre can strip in very long, thin slivers. They're splinters you wouldn't want!

[ArmyAirForce]

If you do notice any splitting or cracking in a carbon fibre object, make a quick trip to a model shop for some ZAP CA Cyanoacrylate glue. It comes in a pink bottle and is as thin as water, if not thinner in viscosity. It usually comes with a very thin PTFE tube to insert into the end of the bottle for accurate application. Because it is so thin, capillary action will draw it into any broken fibres or splits, healing the crack. Be warned, if you're heavy handed, it can run everywhere, and stick in fractions of a second! However, it is very useful.