strengths and relevance

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strengths and relevance

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coleio	coleio posted 11 Years Ago HOT Topic Details
Group: Forum Members Posts: 68, Visits: 285	some of you have probably seen me floating about the forum, asking silly noob questions so heres another one for you. i recently found a page that compared strength of carbon and kevlar as far as i can remember it was on two planes, rigidity and flex. or something to that effect anyhow. i cant find the page but it stated that kevlar was about 20percent less rigid but much much better when it came to breaking points and flex. so, after reading this and thinking about it for a while, taking costs into account i thought of removing carbon from the equation and going for a combination of kevlar and fibreglass. looking into it a bit more i came across this page which goes into much more detail than the first i came across http://www.performance-composites.com/carbonfibre/mechanicalproperties_2.asp so my question here is how much of these details are really relevant? i was going to look each one up but thought id ask here first. i know that with the use of kevlar, woven fibreglass and a good core material like soric sf2 i can make a product better than many aftermarket cf panels. is my thinking wrong here? Bear in mind there are some atrociously poor quality carbon panels out there oh, the application is car panels by the way, bonnets, bumpers etc... thanks guys
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coleio	coleio posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 68, Visits: 285	wozza (17/03/2014) coleio (17/03/2014) yeah i had thought about the equal fabrics either side of the core. would really annoy me if it was 200gsm cf 600gsm fg core then another 200gsm cf the best to do is cf/fg/core/fg/cf but i dont know how thick that would be, cant get my hands on the accurate thicknesses. My standard lay up for body panels is GC50 Gelcoat - 2x200grm CF - 3mm Soric or 3D Core - 1x 450grm CF. That gives a pretty balanced composite with a nominal thickness of 4.5mm using infusion. Wet lay would come out a bit thicker. If you want to reduce cost's you can swap the second 200grm layer of CF for Diolen as its only really there to stop the white of the core showing through on the finished part. i had thought about diolen briefly but couldnt find suppliers who could do 1.5m widths as cheap as fibreglass, is diolen much stronger than fibreglass? wow if that adds up to 4.5mm im probably best to reduce the fg to 400gsm. would the fibreglass show up through the 200gsm cf outer layer? i could get slated for asking this but could i spray the fibreglass layer with matt black aersol spray? or would it react?
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wozza	wozza posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 688, Visits: 5.4K	coleio (17/03/2014) wozza (17/03/2014) coleio (17/03/2014) yeah i had thought about the equal fabrics either side of the core. would really annoy me if it was 200gsm cf 600gsm fg core then another 200gsm cf the best to do is cf/fg/core/fg/cf but i dont know how thick that would be, cant get my hands on the accurate thicknesses. My standard lay up for body panels is GC50 Gelcoat - 2x200grm CF - 3mm Soric or 3D Core - 1x 450grm CF. That gives a pretty balanced composite with a nominal thickness of 4.5mm using infusion. Wet lay would come out a bit thicker. If you want to reduce cost's you can swap the second 200grm layer of CF for Diolen as its only really there to stop the white of the core showing through on the finished part. i had thought about diolen briefly but couldnt find suppliers who could do 1.5m widths as cheap as fibreglass, is diolen much stronger than fibreglass? wow if that adds up to 4.5mm im probably best to reduce the fg to 400gsm. would the fibreglass show up through the 200gsm cf outer layer? i could get slated for asking this but could i spray the fibreglass layer with matt black aersol spray? or would it react? Because the Diolen is not the "seen" layer it can be laid down in pieces from a standard width roll. Most E Glass or woven glass cures clear so you still run the risk of the core showing through, especially around any tight curves/corners etc. Not really sure how/when you plan on spraying the fg but I wouldn't be putting any rattle can products in the stack. Warren Carbon Copies Ltd
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strengths and relevance

coleio - 11 Years Ago

These properties should really be treated as indicative measures only IMO. Far too much will depend...

FLD - 11 Years Ago

[quote][b]coleio (17/03/2014)[/b][hr] some of you have probably seen me floating about the forum,...

wozza - 11 Years Ago

couldnt agree more wozza. my head is wrecked trying to decide which materials and composition to...

coleio - 11 Years Ago

[quote][b]coleio (17/03/2014)[/b][hr]couldnt agree more wozza. my head is wrecked trying to decide...

wozza - 11 Years Ago

yeah i had thought about the equal fabrics either side of the core. would really annoy me if it was...

coleio - 11 Years Ago

[quote][b]coleio (17/03/2014)[/b][hr]yeah i had thought about the equal fabrics either side of the...

wozza - 11 Years Ago

[quote][b]wozza (17/03/2014)[/b][hr][quote][b]coleio (17/03/2014)[/b][hr]yeah i had thought about...

coleio - 11 Years Ago

[quote][b]coleio (17/03/2014)[/b][hr][quote][b]wozza (17/03/2014)[/b][hr][quote][b]coleio...

wozza - 11 Years Ago

Well it would be roughly 1mm on top of your core thickness. Give or take. So if you're using 2mm...

Hanaldo - 11 Years Ago

yeah but i would prefer to have one single piece. besides fg is so so so cheap in bulk. i dunno, i...

coleio - 11 Years Ago

depending on the part, resin, end use etc, you could infuse the outer layer to get your finish then...

ChrisR - 11 Years Ago

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