Hello all!
I was wondering if a thin aluminium sheet is lighter that a fiberglass panel of similar size.
Thanks in advance
It's going to depend on how thick the different materials are. For instance- 1.5mm aluminium would be the same weight as 6mm birch plywood
I don't have any figures for grp I'm afraid.
John
Thanks for the reply.
I was thinking to remove a couple of fiberglass bodywork panels off my car and replacing them with thin aluminium sheet (something like 1mm thick
ones)
By doing this I think the car will be braced structurally and also will be lighter.
I am not sure about the lighter bit though that is why I am asking.
Also I was planning to paint them so they will weight a bit more than bare aluminium.
I hope this makes any sense
I think the main problem in answering that question is it depends very much on unknown factors
- Thickness of aliminium sheet
- Grade of ally
- Resin used in GRP (polyester or epoxy)
- Type of matt used (CSM/woven/one thick sheet/ multilayer thin sheet)
- Forces applied to panel (twisting, pulling, bending)
- Method of attachment of panel to bodywork
However, all things being equal, most GRP bodywork panels are fairly non-structural polyester GRP. Replacing with aliminium (if you sikaflex and rivet
it) will introduce some structural rigidity into the chassis for the same weight (or even a little less than GRP).
And that's ignoring the fact that the care and attention in the way GRP has been laid up, bubbles removed etc can make a huge difference to the strength of the final piece....
Are they stressed panels? If so go the ali way and bond and rivett. What you gain in weight will give you more rigidity. We are only talking tiny amounts in any respect. Are you racing it?
just dont have that bacon sandwich and cup of tea before you race!
quote:
Originally posted by tomblyth
just dont have that bacon sandwich and cup of tea before you race!
Fairly thin GRP (1 layer of 600 GSM plus gelcoat) is going to weigh 1.5kg per square metre minimum, about the same as 0.6mm aluminium. The bodywork I'm making is about 2.7 kg /m2 or the same as 1mm aluminium.
Originally I was going to fit fibreglass front mudguards and rear wheel arches to my car,
then after having a bash (pun intended) at making my nose I decided to make ally guards and arches.
According to the kitchen scales, the Lolocost front guards that I had bought
and the 16g ally ones I made were exactly the same weight. 
I will of course have reduced the ally down to 30g by the time I have polished them. 
Cheers,
Paul G
I just bought some rear arches from a guy in the States. In order to fit the 13" wheels correctly, he added these overhanging flanges to the arch
itself so it matches the contour of the wheel. They are HEAVY! Any 1 - 1.3 mm ally would be way lighter I am sure.
I am considering calling Carbon Mods again, since the front wings are so nice - and light. Hey what's a few extra hours of work for a nice car?
The car is only a trackday car never meets the road. All the interior is made out of carbon fibre plus wings etc.
The bodywork is the standard MK fibergrass panels.
So to make sure if I understand correctly
the ali side panels dont weight significant less but offer rigidity to the chassis.
So I shall go for it then..
Maybe you should have a look at usign dibond, a sandwich panel with two 0,3mm aluminium skinplates bonded to a PE core. My car has 2mm total bidond
sides which weigh next to nothing. (and a flippin' heavy pinto ;-))
Look here
thanks for the reply do you have any ppics of that material fitted on your car because the website haven't got any pics
i had to raise the boot box floor on my dax and after cutting the fibre glass off and replacing with 1.2mm ally i couldnt believe how much lighter it was! felt bout half the weight... far far lighter but can be hard to work into shapes specially curves
quote:
Originally posted by :{THC}:YosamiteSam
i had to raise the boot box floor on my dax and after cutting the fibre glass off and replacing with 1.2mm ally i couldnt believe how much lighter it was! felt bout half the weight... far far lighter but can be hard to work into shapes specially curves
Thank you very much all of you.
You been really helpfull. I will proceed then to remove the side panels and replace them with ali ones.