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Bonding / Laying Up Carbon Fibre (Where Are You Mr Hignet?)
scootz - 30/11/11 at 03:35 PM

Quick re-cap on where I'm at!

My chassis-tub is CF and I'll be bonding in an alumium honeycomb panel for the floor. You can see the recessed 'lip' where the honeycomb panel will fit into in this pic...



Am I right in thinking that epoxy resin is the best stuff for this job? Also, as far as the technique goes, is it just a case of roughing up both surfaces a little and cleaning them before fitting?

Next issue...

A 0.5" honeycomb panel leaves me with a flat floor. I'm guessing that the resin used for the initial bonding of the panel to the tub will not be strong enough, so I plan to buy some CF cloth and cut sheets to the shape of the whole floor area. How should I approach this one? Again, rough up, then clean down the ali / CF floor, but what next... ???

Do I lay the CF cloth on the floor and wet it with epoxy resin, or should I apply a covering of resin on the floor surface before putting the cloth down? How long should I leave it before putting on the next layer? And finally, how many layers should do the (permanent) job!?

Thanks muchly in advance!


twybrow - 30/11/11 at 04:12 PM

Yes, epoxy would be more suited to your work with carbon - just make sure you find a system that gives you the mechanical properties you need, at a cure temperature/condition you can achieve at home!

Abrade (rough grit paper), vacuum, degrease with acetone or similar.

I would overlaminate your join as you suggest, but you may want to consider a primer for the ali panels - eg an etch primer to avoid problems of oxidation alter on.

Final question I would say you can do it either way. Hand laminating os normally a case of wetting out the area you are about to work. Then drape on your fabric, then work the resin through the fabric.... And I am not going to comment on how many layers, as I have no idea how good your lamintating is, the loads you are subjecting this too etc...


scootz - 30/11/11 at 05:40 PM

Thanks very much!

quote:
Originally posted by twybrow
... I have no idea how good your lamintating is, the loads you are subjecting this too etc...


LOL... neither do I.


phelpsa - 30/11/11 at 06:44 PM

In reality you're concern is more going to be the bonding area than strength of the material. You might find it much easier to just glass it in rather than use carbon, neither are going to look particularly neat

[Edited on 30-11-11 by phelpsa]


snakebelly - 30/11/11 at 07:50 PM

If your planning to cover the whole floor with carbon cloth I woul consider Kevlar cloth instead far more abrasion resistant than carbon and the process would basically be the same


scootz - 30/11/11 at 08:07 PM

Cheers fella's!


v8kid - 30/11/11 at 08:27 PM

0.5" honeycomb is seriously strong do you really need to sheet it all over? I would have thought an epoxy paste on the mating surfaces would be strong enough. I am holding a good few tons of slate roof up on my extension just with a few bolts epoxied into the existing wall so I should imagine it would be strong enough.

What do the tub manufacturers recommend?


Neville Jones - 30/11/11 at 08:33 PM

In the trade, the floor would be bonded in (if bonded and not mechanically secured), using an epoxy adhesive.

1/2" honeycomb floor, with properly specced cf either side, will be near bullet proof, and maybe a bit overkill.

1/2" hd foam will do the job easier and cheaper, and just as structural for the purpose. A couple of layers of woven glass either side, and jobs done.

Cheers,
Nev.


Uphill Racer - 2/12/11 at 12:30 AM

Are you considering using the underside of the trike to provide low drag downforce? If so it maybe worth laying up the floor and venturi's together before bonding in.


Uphill Racer - 10/12/11 at 11:41 PM

That a no then....................................?


scootz - 11/12/11 at 11:42 AM

Apologies... never saw your post.

No, the floor will be doing nothing other than stopping my chubby arse from scraping along the ground.


matt_gsxr - 11/12/11 at 12:28 PM

Lexan is very strong and would make it a bit different.


scootz - 11/12/11 at 01:29 PM

I'll have a wee look!


Uphill Racer - 12/12/11 at 01:14 AM

quote:
Originally posted by scootz
Apologies... never saw your post.

No, the floor will be doing nothing other than stopping my chubby arse from scraping along the ground.


No problem, thought a bump may help.....

I have had a love affair with 3 wheels since I owned this Berkeley in the 60's.



I think it is a shame that your not using aero.
Your concept provides the ability to generate levels of low drag downforce at road car speeds that should make you think your tyres are made of super glue.

When Ian Scott's 4 wheel drive was at the design stage we chatted about using close coupled rear wheels with large venturi unhindered as in a conventional 4 wheel car. I'm sure it has been done but I haven't seen it and would love to.....


orton1966 - 12/12/11 at 07:00 AM

I'd be tempted to used a suitable methacrylate adhesive (plexus, lord etc.). Structural, much more tolerant of preparation and material differences and not as reliant on elevated cure temperatures.

Like others have said I can’t see the benefit in over-laying the whole floor, if you want belt and braces, use a neat woven tape just around the joint on the underside


v8kid - 12/12/11 at 07:57 AM

quote:
Originally posted by Uphill Racer
quote:
Originally posted by scootz
Apologies... never saw your post.

No, the floor will be doing nothing other than stopping my chubby arse from scraping along the ground.


No problem, thought a bump may help.....

I have had a love affair with 3 wheels since I owned this Berkeley in the 60's.



I think it is a shame that your not using aero.
Your concept provides the ability to generate levels of low drag downforce at road car speeds that should make you think your tyres are made of super glue.

When Ian Scott's 4 wheel drive was at the design stage we chatted about using close coupled rear wheels with large venturi unhindered as in a conventional 4 wheel car. I'm sure it has been done but I haven't seen it and would love to.....


interesting concept. The center of pressure of the downforce would be skewed towards the rear exactly where it is needed. However this meand that the handling at low speeds would be far worse in comparison to the improved high speed handling - ditto brakes. Like driving a F1 car on the road

Still I'd go for it - why didn't you pursue it?

Cheers!


Uphill Racer - 13/12/11 at 01:33 AM

quote:
Originally posted by v8kid

Still I'd go for it - why didn't you pursue it?

Cheers!


Ian thought the mid engine Kawasaki driving 4 wheels was enough to deal with at that time and as a sprint and hillclimb car had the MSA to deal with.





We also thought about how a 3 or 4 wheel close coupled rear end could be independent from the tub allowing rear roll resistance with steer, happy hours spent conjugating over a bottle of wine.

Ian Scott 30.7.1948-14.11.2009 RIP.