How much does carbon fibre sheet cost, and how easy is it to curve round the bottom to make the dash. Ive seen a few carbon dashes that has a nice shiney finish and are curved round the bottom.

I have worked with thin carbon fibre sheet at uni, but never curved it or had it finished like the dashes ive seen its had quite a dull finish. How do you get it so shiney

Thanks

If you want a curve bottom radius, Stuart Taylor do them 'off the shelf'

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Originally posted by greggors84
How much does carbon fibre sheet cost, and how easy is it to curve round the bottom to make the dash. Ive seen a few carbon dashes that has a nice shiney finish and are curved round the bottom.

I have worked with thin carbon fibre sheet at uni, but never curved it or had it finished like the dashes ive seen its had quite a dull finish. How do you get it so shiney

Thanks

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From what I know you have to bake CF, but I may be wrong (I often am!)

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Originally posted by Jasper
From what I know you have to bake CF, but I may be wrong (I often am!)

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It has to be baked if it is pre-preg .....i.e. pre-impregnated with resin...(to retain the best properties)....most of it may well be for all I know, but I'm pretty certain you can lay it up normally by hand with regular polyester resin. It will look OK but won't have anywhere near its full mechanical properties...

Check out Dennis Brunton's Stalker dash....

http://www.angelfire.com/biz6/stalkerv6/compo.html

I've worked with carbon.

When using it for non-structural parts (so strength is not critical) you can use polyester. (epoxy would be better: the fibres have received a coating to improve the bonding with epoxy).
You don't have to use an oven.

I use a clear gelcoat, and the end result is really very good. O.k. I'm not using it for strength, only for outlook.

Only use the carbon as a top-layer and build your part up to the required strength with woven glassfibre. Then you still end up with a light and strong part. (and stunning looks).

Don't be scared: just try it, and see for yourself!

My current bedtime reading is "Competition Car Composites".

Currently I am reading the chapter about material upgrades and in it the author (Simon McBeath) describes using CF in a polyester resin construction.

He states that you can use CF as a direct replacement to Chopped Strand Mat or Woven matting glass fibres. Also that the properties of the CF will be utilised. ie; if CF is 5 times stronger than CSM then you could make the component 1/5 of it's original weight to be the same strength as CSM component.
The properties are within the materials being used, so if you use CF it will be stronger.

What you must do is make sure that you specify CF to be used with Polyester resin when you buy it and not get Pre-preg.

As stated above it might not be as strong as if using Epoxy or by baking, but it will still be a lot stronger than Glass Fibre.

Terry

As long as the bonding between fibers and polyester is good, the strength will indeed be very good. However, most available CF is treated to bond to epoxy, and not to polyester. That's why you probably won't be able to use the strength. The fibres will simply not stick to the polyester enough.

If you need strength, use epoxy. (or try really, really hard to source some CF that has been treated for polyester. But that won't be easy!).

Trouble is, epoxy is such a pain to use - doesn't 'wet' the cloth as easily as polyester resin, and you have to be careful to avoid skin contact and inhaling fumes (which, incidentally, have very little smell so you don't know that you're inhaling them!).

At least with polyester resins you always know that you're breathing them in! (very smelly, if you've never experienced them).

The epoxy resins make a damn good wood glue though!

cheers,

David

So where would one get some carbon fibre matting stuff either pre-pregged or not?

I'm planning to visit CFS tomorrow,so I'll see what they suggest. I'll be asking for the locostbuilders discount price.........worth a try.
Ian

Re the strength of a c/f dash: I have bought a Stuart Taylor c/f dash for my ST - looks great, shiny and with a nice radiused rolled return on the bottom edge.

It may be just that I'm not very familiar with c/f, but it seems very light and thought it might distort a bit when I fix instruments in it.

I was wondering if I should support the back, say by glueing some thin plywood on the back?

In particular, I think I am going to have to cut the bottom edge to go round the steering column, so that will weaken what would be a good strong "beam" effect of the rolled edge.

Any thoughts?

[Edited on 13.04.2005 by Humbug]

I got gts to do em a carbon fibre dash with a curved bottom edge. They are not prepreg carbon, just a wet layup with grp back iirc.

Ned.