carbon fibre wishbone. bonding method?

[joesnif]

I am currently designing some prototype carbon fibre wishbones as part of a final year project of my degree. These will probably be made from commercially available cfrp tubing with steel (or possibly aluminium) inserts that will have to be bonded in in order to fit the ball joints.
I was wandering if anyone had tried a similar setup and what experience they had had with different glues. Any recommendations would be appreciated.

[joesnif]

I am currently designing some prototype carbon fibre wishbones as part of a final year project of my degree. These will probably be made from commercially available cfrp tubing with steel (or possibly aluminium) inserts that will have to be bonded in in order to fit the ball joints.
I was wandering if anyone had tried a similar setup and what experience they had had with different glues. Any recommendations would be appreciated.

[Draksia]

This is also something we are considering very seriously. So if any body has any info that would be helpful.

[Mike Claffey]

We use a 2 part araldite expoxy for that sort of thing.

[fsae_alum]

Loctite makes some really good structural adhesives (Hysol) for bonding composites to metals. In the type of bond joint you are looking at, you will need some clearance designed in between the composite tube and the insert to accomodate the adhesive. Likewise, you will need to make sure that the surfaces of both parts are prepped well (remove all mold-release, make sure surfaces are porus, etc...).
Last not not least, you will need to figure out how to do the slip joint bond without pushing out all of the adhesive out of the joint. This can be done by using wires (same diameter as the adhesive clearence) inserted around the perimeter of the joint to ensure that the correct clearence is maintained for the bond assembly. You'll also need to determine if the adhesive requires you apply and maintain pressure and/or heat (watch out CTE) for a prolonged time to cure the adhesive and if so need some way of doing it repetitively and consistently (bonding fixture). Call Loctite (Hysol) and they will tell you what needs to be done to work with their adhesive. Best of luck.

[joesnif]

Cheers for that. looks like hysol is the way to go.
Has anyone tried strength testing joints with the metal insert bonded inside the cfrp tube opposed to it being a sleeve that the tube fits into or a combined sleeve and insert piece which would give double the area for the adhesive to bond?

[MH]

3M Scotch Weld 9323 B/A aka "pink glue".
Strongest aerospace (cold) glue. Anodize metal surface for best result. Mix small glass balls (0.2 mm) in glue.
That's how we're doing that for years now....

Delft University

[Draksia]

I am guessing you are using the glass balls to create the proper spacing for the glue?


Also I can't seem to find anything about Scotch Weld 9323 on the US 3m site. Do you happen to know if this is a UK product because the only the data sheet I have found is from the UK division.

[MH]

Yep, good guess.

Sadly I don't know if this is a Uk product, but a quick e-mail to the US division will tell. We never had to search the US, we just found it at the Aerospace faculty http://fsae.com/groupee_common/emoticons/icon_smile.gif

MH

[Ben C]

We use a 2 part epoxy, Loctite Hysol E-30CL. It dries clear.

Ben
http://www.mame.mu.oz.au/formulasae

[joesnif]

Cant find Loctite Hysol E-30CL or 3M Scotch Weld 9323 for sale off any UK websites. Does anyone know if these are avaliable anywhere in the uk or if not what similar uk products are called?

I also need to find a supplier of the glass spacing beads to mix into the glue.