doughie
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| posted on 14/12/06 at 03:40 PM |
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GRP storage
whilst waiting for my GRP bodyshell (locost) am thinking about storage...
any problems storing outside?? apart from theives!
[Edited on 14/12/06 by doughie]
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graememk
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| posted on 14/12/06 at 03:45 PM |
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when i left he bonnet off my car it went out of shape
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nick205
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| posted on 14/12/06 at 03:50 PM |
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most of my bodywork was stored outside under a tarpaulin before it was fitted and doesn't seem to have suffered any ill effects.
Like Graeme points out it's worth considering how you place it so as not to deform any parts over time though.
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twybrow
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| posted on 14/12/06 at 04:26 PM |
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Make sure you keep it cool and out of direct sunlight. Ideally it should be held relatively rigid and not allowed to deform. Fit some wooden battens
to the back of the part to help support it until it is ready to use. Hope this helps.
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RazMan
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| posted on 14/12/06 at 04:28 PM |
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New fibreglass tends to 'move' for the first 3 months of its life and the main thing to be careful of is temperature extremes, especially
direct sunlight. Also, if left unsupported you will find that shut lines change.
If you can, make a frame to keep everything in shape.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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tri
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| posted on 14/12/06 at 04:31 PM |
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we left ours under the house (same as outside but more secure) was fine when we went back use it just make sure its flat like everyone else has said
tri
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Syd Bridge
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| posted on 14/12/06 at 05:28 PM |
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If any bodywork deforms in the sun, what will it be like with a hot engine under it??
This is a symptom of using cheap resin with a low Tg point. (glass transition ie hard to putty).
If any bodywork deforms under heat, it is unfit for purpose.
Throw it back at the manufacturer and ask for some that's made from quality resin. The good stuff is about £1~£1.50/kg dearer than the cheap
stuff. And how many kilos are in a full set of Locost mouldings? About £10 worth, at best.
Cheers,
Syd. 
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twybrow
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| posted on 15/12/06 at 12:07 PM |
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Cost of resin has little to no relationship to shrinkage. Some resin mixes are more prone to shrinkage than others, but outperform in other areas. I
assume the GRP is made from polyester resin (cheapest, readily available, easy to use etc). This is the worsst for shrinkage. On a car, the engine and
heat will help to 'post cure' your part (if the manufacturer hasn't already), but remember on a car it is supported so should resist
significant movement. Tg has more of an effect on brittleness and rigidity.
Best bet is support it, leave it cool and dark until it is fixed in place and if it warps then send it back.
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Syd Bridge
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| posted on 15/12/06 at 07:27 PM |
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quote:
Originally posted by twybrow
Cost of resin has little to no relationship to shrinkage. Some resin mixes are more prone to shrinkage than others, but outperform in other areas. I
assume the GRP is made from polyester resin (cheapest, readily available, easy to use etc). This is the worsst for shrinkage. On a car, the engine and
heat will help to 'post cure' your part (if the manufacturer hasn't already), but remember on a car it is supported so should resist
significant movement. Tg has more of an effect on brittleness and rigidity.
Best bet is support it, leave it cool and dark until it is fixed in place and if it warps then send it back.
Shrinkage is usually in direct relationship to styrene content. The more styrene, the greater shrinkage, the cheaper the resin.
Post Cure?? Usually reserved for epoxies and like. How many manufacturers even know what it means? I use a high end poly that benefits from post cure,
and it is twice the cost of the cheaper useable stuff.
Tg...You better get your manufacturers spec sheets out to learn more about the relative importance this has. As I said, Tg is the point it changes
from hard to soft, so can then deform.
If you want to know more, I've been doing this stuff for more than 40 years!!!Look to the left for further clues. 
Cheers,
Syd.
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twybrow
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| posted on 19/12/06 at 12:56 PM |
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Saying you have been doing it for 40 years menas nothing to me. Otherwise all 'experpienced' memebers of society would be experts in their
field - this is not the case. You can do the same thing for forty years and still be rubbish at it (I am not saaying this applies to you, i
don't know you)....
Post curing is used to increase the cross linking of the resin system, which can have the advantage of increasing the Tg. so whilst you are saying Tg
is the be all and end all property, i am saying there are factors which affect Tg which can play a significant part.
As previously stated, Tg has an effect on rigidity and brittleness - it is the point a plastic changes to a glass (in terms of physical behaviour). A
plastic will typically deform and return to its original shape. Glass will not.
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Syd Bridge
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| posted on 19/12/06 at 07:38 PM |
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I'll defer to your obviously far greater knowledge. Even though that same knowledge contradicts accepted norms in the composites industry.
You'd better write some new text books, as you seem to have made discoveries which overturn years of modern teaching.
And my engineering degrees and more mean nothing, in the presence such hallowed intelligence!
Cheers,
Syd.
I was working with carbon fibres in R&D in 1974!!!Helicopter blades. Built a cfrp skiff in 1975, and masts in 1976. Rudders and shafts in 78/79,
and racecars in 80/81. Then I got serious!
That enough 'experience' in my forty years at it?
[Edited on 19/12/06 by Syd Bridge]
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scotty g
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| posted on 19/12/06 at 08:40 PM |
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good God, stop it the pair of you!
Can we all agree that if the panels are left outside that they should be wrapped up, supported and as sheltered as possible.............PLEASE!
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Syd Bridge
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| posted on 19/12/06 at 08:58 PM |
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Sorry sir, won't do it again, promise.
Cheers,
Syd.
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twybrow
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| posted on 20/12/06 at 08:44 AM |
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Yes we definately can all agree on that! Leave it out of sunlight, supported and cool.
Syd - i dont know you so i wouldn't make any comment to that effect.... I am not re-writing anything, just trying to have a discussion with a
fellow composites man.
Incidentaly is yous 'high end polyester' an isophthalic or ortho?
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Syd Bridge
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| posted on 20/12/06 at 09:15 AM |
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Promised not to say any more.
Cheers,
Syd.
And it's a modified iso.
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emsfactory
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| posted on 21/12/06 at 10:32 PM |
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enjoying this.
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PaulBuz
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| posted on 22/12/06 at 01:52 PM |
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Damn, is it finished? ...only just got back with the popcorn
ATB
Paul
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Syd Bridge
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| posted on 22/12/06 at 04:06 PM |
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Bad Luck!!!
Switch across to the thread in 'Chassis' regarding suggestions for the McBearen.
Cheers,
Syd.
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