Strength of fibreglass?

hugekim · Post by **hugekim** » Wed Oct 21, 2009 4:05 pm

I recently bought a VS rear bar from UAS and it's about to be put onto my car. The bar has some very minor cracks on it already (most likely from transit) and my panel beater was kinda stressing the fact that fibreglass is fragile and not suitable for day-to-day driving. He said he can make it look good now but that it will definitely crack again in the future.

Is this true? Is it likely that just during some daily driving (e.g. going over a speedhump) that the bar could crack?

Just after some opinions of you guys who currently have fibreglass bodykits.

Cheers

Tippin · Post by **Tippin** » Wed Oct 21, 2009 4:32 pm

yes, fibreglass kits are quite fragile ...

any decent impact will crack them, obviously some bars are better quality than others as they are thicker

as for repairing your bar, as long as the damage isnt to drastic where it would cause a major weak spot in case of an impact, a normal fibre-glass repair should hold up fine ...

it is more so when you fibreglass over metal that you would find it to crack in the future due to expansion

eddiii · Post by **eddiii** » Wed Oct 21, 2009 5:50 pm

i have a vs front bar, an i have had many scratchs at humps or some drive way, but it has not crack yet, just scratches under the bar, maybe cause im going slow speed? it might break/crack if u bump it in high speed, but so far its all good for a daily car for me.

arctan · Post by **arctan** » Thu Oct 22, 2009 12:47 am

lol where's jono when you need him
I think he goes through a veilside front bumper every 6 months

Post by **I8A4RE** » Thu Oct 22, 2009 10:29 am

If you hit it hard it will crack. If it is good quality it wont get damaged from just driving...... only hitting it.

I have had my bozz for 2 or 3 yrs now and have never had any drama's with it.

Jamie · Post by **Jamie** » Thu Oct 22, 2009 6:19 pm

Thats crap! If fibreglass was so fragile boats wouldn't be made out of the stuff. If the product is of good quality it will be fine

bushido · Post by **bushido** » Fri Oct 23, 2009 12:49 pm

fibreglass (and all other glass fibres) are not weak in terms of strength. Like most composites, they have veyr high strength to weight ratios but are extremely birttle. They tend to fail under lower cyclic stresses when compared to metals/plastics of similar strength since the whole principle in there construction is bonding glass fibres with resin. Unlike metal or plastic where they are cast as one molten piece. So to answer your question, fibreglass is not weak, it is just brittle so yes any hard impact will cause micro fractures in the material, eventually leading to failure. This is because they do not exhibit nearly enough elastic deformation if you were to examine a stress/strain diagram.

Tippin · Post by **Tippin** » Fri Oct 23, 2009 5:37 pm

your an engineer arnt you?

SchumieFan · Post by **SchumieFan** » Fri Oct 23, 2009 5:49 pm

lol... basically, it depends on the quality of resin

hugekim · Post by **hugekim** » Sun Oct 25, 2009 1:04 am

Thanks for the replies especially bushido's haha

Maybe I should have got it installed I decided to repair my stock bar instead.

Guess I'll be selling a brand new VS rear bar... from Unique Auto Sports, very minor cracks (I'll post some photos later) and it fits well.

J · Post by J » Sun Oct 25, 2009 9:06 pm

just get some fiberglass and strengthen the whole thing from behind.

my t's factory bar was reinforced with more fibreglass around the bottom of the lip. i have a few deep scratches underneath but no cracks where it was reinforced.

bushido · Post by **bushido** » Mon Oct 26, 2009 4:29 pm

Tippin wrote:your an engineer arnt you?

yes...

Post by **Bennoz** » Mon Oct 26, 2009 8:21 pm

I am too... gave it away to work in IT. The chicks in offices are heaps better looking than factory chicks

bushido · Post by **bushido** » Tue Oct 27, 2009 10:55 am

hmm true ben. But I wont be working in an office. I 'll be working in the field with the army..so the chicks will be

Post by **Bennoz** » Tue Oct 27, 2009 11:35 am

Ya sure?

Then again, maybe I've seen one too many porno's