Roman

Fibreglass, Carbon Fibre, Paper Mache - The composites chat thread

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1, I had the hood laying on the lawn out of the way, he wasnt watching where he was going.

2, nope, he was nearly twice my weight LOL

3, yup, he has to bend over to get through doors.

And yes, from my experience a glass part has to be considerably thicker.

My suggestion is to get some glass and some cf and start playing around. You need to fool around for a bit before committing to a big part anyway.

Ali express cf is great.

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I think there's not much of a financial case to not use CF.

As in, why are carbon fibre parts expensive to buy? Because its so bloody labour intensive.
Then the costs for moulds, resin, bags, vac pump and so on. 
So the cost of the material itself is inconsequential.
Going through all the same motions anyway, but then using fibreglass. Why would you.

I think it's one of those things where, imagine back in the 70s (or whenever) where this was a space age material. 
Race teams etc etc would kill each other to get it. If they could even afford it.
Or if anyone even knew how to use it. Or if they even had good enough epoxy.
Now its so cheap, we have the time, we have the information, we have the technology...
But we struggle against the thought of buying fibreglass so we can have more bucks for beers and big macs.
I think we owe it to our forefathers, to make shitty parts from cost effective exotic materials to the best of our abilities.

Some benefits of not using it though. Are avoiding the galvanic corrosion fuck-around when you put it up against metal.
As fibreglass doesnt have that problem, nor is it conductive. 
I've yet to see anyone quantify how much of a problem this is in real life though.
I mean I still see old BTCC cars running carbon intakes and so on, without the engine block turning into dust.

 

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So.....Carbon Fibre the world... Easy as.

Has someone found Carbon Cloth in Widths big enough for Bonnets on Ali?

 

 

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5 hours ago, flyingbrick said:

 

My suggestion is to get some glass and some cf and start playing around. You need to fool around for a bit before committing to a big part anyway.

Ali express cf is great.

All of this, I started by making some moulds in fibreglass to figure out what works and what doesn't... 

Its not as daunting as you might think. 

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6 hours ago, japawagons said:

So.....Carbon Fibre the world... Easy as.

Has someone found Carbon Cloth in Widths big enough for Bonnets on Ali?

 

 

I was having a nosey around at Leadfoot. And a few other events. 

What I notice is that a lot of racecar parts arent perfectly smooth shiny etc etc. Pinholes and bubbles etc galore haha.

But also some cars just have the bonnet in two halves. Visually it can look nice if you match up the weave. 

Speaking of which, holy shit I'll find this link I saw on facebook a while back. 

Hold the line caller

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I imagine that was made with prepreg? Which would make alignment possible

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Have you used spray tac Roman? helps immensely with getting cloth to stay where you want it.

 

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10 hours ago, mjrstar said:

All of this, I started by making some moulds in fibreglass to figure out what works and what doesn't... 

Its not as daunting as you might think. 

Yeah I definitely think it's well achievable. Your work looks really good but that goes along with the general theme of your work.
 

How many layers of Carbon did you use for your dash? 

 

8 hours ago, Roman said:

I was having a nosey around at Leadfoot. And a few other events. 

What I notice is that a lot of racecar parts arent perfectly smooth shiny etc etc. Pinholes and bubbles etc galore haha.

But also some cars just have the bonnet in two halves. Visually it can look nice if you match up the weave. 

Speaking of which, holy shit I'll find this link I saw on facebook a while back. 

Hold the line caller

 

I've definitely found this to be the general theme in most 'professionally' built race cars. They just get in and get it done. Fit for purpose quality over perfection is definitely the go. As long as I can end up tidier than a drift car, then i'll be happy. 

Managed to source a Vacuum pump from the Mrs' Lab. Need the shed to be a bit bigger but once things fire up again, I'll look into moulding. I did some calculations a year or so ago and found that at least 10kgs per panel can be saved in the Boot and Bonnet by making them carbon.

Just need to find a tidy way of a making wider front guard moulds. 156 GTA guards are wider but people want moonbeams for those panels, seems wasteful to buy them just to mould. 

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Just now, japawagons said:

Yeah I definitely think it's well achievable. Your work looks really good but that goes along with the general theme of your work.
 

How many layers of Carbon did you use for your dash? 

 

Hey, 

Its 2 layers with some stiffening ribs on the back plus a small section of the plastic dash frame (including a bit to hook up the demister vent in the drivers side) & to mount to the factory dash bar. 

 

Could definitely be lighter by running a dedicated rollcage dash bar and using thin wall aluminium tube to make it mount / clamp to the cage dash bar. 

The weave is a bit of a bitch to lay over compound curves, but close enough was good enough for me. It looks much better after a sand back and a couple of coats of satin clear instead of the high gloss clear. 

The fine twill? is supposed to help with drapability but someone with first hand experience might be able to chime in. 

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On 10/04/2020 at 10:23, Roman said:

This guy! Bloody hell 

I cant believe someone can trim the edge of carbon that nicely. Then align it too. Amazing.
 

71189913_10221094467659176_8076526841524912128_o.jpg

71149932_10221094468579199_3102241086760812544_o.jpg

the trick is to not use scissors. They lay down masking tape over the inside face of the  cut first and use a pizza cutter style tool to get perfect cuts.

 

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If ur worried just smash down a layer of glass first.

Ps, you watching the scrappy build? Well worth it for anyone wanting to learn how amazing cf is

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On 12/04/2020 at 01:20, flyingbrick said:

If ur worried just smash down a layer of glass first.

Ps, you watching the scrappy build? Well worth it for anyone wanting to learn how amazing cf is

On the subject of Glass 1st.

Would using an outter layer of carbon and then supported my 1-2 layers of Glass, aid rigidity but also balance cost?

Basically Glass weave is like $60 for 1mx10m. The equivalent in Carbon is closer to $400. Once you go to wider Cloth, it climbs further.


My plan is to build Glass, Guards and Bumper, then modify the glass panel, to make wider guards and a splitter mould, then potentially make these from Carbon.

But tbh, besides absolute critical weight savings and the wank factor of Carbon, I'm starting to think the cost and repair-ability of Glass makes it more attractive.

 

 Fuck I really need to find that properties chart I saw years ago, that balanced Carbon, Kevlar and Glass.

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Simplified, if you're loading a beam, the outermost fibres carry the load.

Carbon over glass will be only just less than 100% carbon in strength for something such as a car panel.

Worth remembering that to achieve weight benefits of carbon over glass in a wet layup you'd need to be A+ in the execution, carbon is a pain to wet out and most people end up chugging in too much resin.

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Just ordered some ADR243 Resin from Adhesive Technologies. (Based in West Auckland) 
Which is low viscosity and good temp resistance.
It's resistant to about 117 degrees with a post cure and designed for infusion. So should make life easier.
So should be good for any engine bay stuff, so long as it's not too close to the exhaust.
So hopefully no more issues with dry areas and the epoxy starting to cure before its even flowed across / pot steaming up and exploding haha.

Hopefully it works out well but I'll need to sort out how to post cure it to get full strength/temp resistance. 
Will do some googlez but I've got our old oven sitting in the carport... 

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