w.olly
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| posted on 21/4/12 at 05:54 PM |
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All GRP panels
Areat folks, i ma trying to work out roughly how much weight i can save if i make all the panel work from GRP instead of ally, but i need to know how
many sqm area there is?
I was going to get giddy and use carbon fibre, untill i seen the cost  , would look cool though hey
So any idea on the sqm needed to cover all the panels?
cheers
wolly
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macc man
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| posted on 21/4/12 at 06:10 PM |
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I would imagine that alloy panels are lighter than grp panels. Unless you make them from light tissue.
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Slimy38
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| posted on 21/4/12 at 06:36 PM |
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Have a look on here for a comparison of materials;
http://www.ecfibreglasssupplies.co.uk/t-GlassReinforcedPlastics.aspx
If I understand the term 'specific gravity' correctly, it suggests that a panel made from CSM and of similar tensile strength as aluminium
will be slightly less than half the weight.
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w.olly
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| posted on 21/4/12 at 06:47 PM |
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well from my workings out
10 sqm of 1.5 ally is 89lds
20 sqm 0f 300grm ( 2 layers ) gsm with resin is 55lbs, ex gel coat
more could be saved in other grp methods if using a glass fibre cloth or woven roving.
thought it would be worth looking into as a weight saver and maybe cheaper.
beat me to it Slimy
[Edited on 21/4/12 by w.olly]
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Slimy38
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| posted on 21/4/12 at 07:06 PM |
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Yep, that table suggests woven roving or cloth would yield a stronger panel, at the expense of being less workable. But if you're looking at
replacing ally I'm guessing you're not looking at complex curves?
If you want the carbon fibre look you could always add just one layer on the outside face? You won't have the ultimate strength to weight ratio
of a full fibre panel, it won't be any weaker than GRP but it'll be a whole lot prettier? That's what I'm planning to do (if I
get round to it!)
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w.olly
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| posted on 21/4/12 at 07:28 PM |
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quote:
Originally posted by Slimy38
Yep, that table suggests woven roving or cloth would yield a stronger panel, at the expense of being less workable. But if you're looking at
replacing ally I'm guessing you're not looking at complex curves?
If you want the carbon fibre look you could always add just one layer on the outside face? You won't have the ultimate strength to weight ratio
of a full fibre panel, it won't be any weaker than GRP but it'll be a whole lot prettier? That's what I'm planning to do (if I
get round to it!)
Yes at the minute i will be just doing the flat sheets, i have done a bit before in my boating days, easy to do with a sheet of hardboard to get a
good flat surface to lay up on, i am going to see what i need when i come to do the body and i ite do a whole new rear and nose cone , depends on
how excited i am to to te it going.
I like the idea of a surface carbon fibre with roven onderneath, didnt think of that, good call kida. Bjut at £25 - £30 per sqm
still the Q needs an answer, how many sqm area on the builds?
[Edited on 21/4/12 by w.olly]
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madmog
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| posted on 23/4/12 at 01:29 PM |
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quote:
Originally posted by w.olly
quote:
Originally posted by Slimy38
Yep, that table suggests woven roving or cloth would yield a stronger panel, at the expense of being less workable. But if you're looking at
replacing ally I'm guessing you're not looking at complex curves?
If you want the carbon fibre look you could always add just one layer on the outside face? You won't have the ultimate strength to weight ratio
of a full fibre panel, it won't be any weaker than GRP but it'll be a whole lot prettier? That's what I'm planning to do (if I
get round to it!)
Yes at the minute i will be just doing the flat sheets, i have done a bit before in my boating days, easy to do with a sheet of hardboard to get a
good flat surface to lay up on, i am going to see what i need when i come to do the body and i ite do a whole new rear and nose cone, depends on
how excited i am to to te it going.
I like the idea of a surface carbon fibre with roven onderneath, didnt think of that, good call kida. Bjut at £25 - £30 per sqm
still the Q needs an answer, how many sqm area on the builds?
[Edited on 21/4/12 by w.olly]
To use a layer of carbon then a layer of glass, you should really use (expensive) epoxy resin for both rather than polyester. Polyester resin has a
different expansivity ratio to carbon and so I've heard from boatbuilders, gives you a weaker resulting material than glass and polyester. Also
polyester resin doesn't stick very well to dry epoxy resin. Epoxy sticks well to dry polyester though. So if you make the glass/polyester layer
first then add the epoxy/carbon to the outside it should be fine but will need work to get smooth. Or make the carbon layer first but use epoxy resin
with the glass. Oh epoxy resin won't dissolve the temporary glue that holds together csm so it will be more difficult to work.
Sorry to add difficulties.
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