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OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 8:28 pm
by xvivalve
OK, a theoretical question...
IF, and I stress IF, we could produce a GRP rear wing, could it be successfully fitted to a car?
I suspect it would have to be the full tonneau, ie including the D post up to underside of the roof to avoid an almost impossible join between GRP and metal...
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 9:07 pm
by Carledo
Well, if you can produce a "test article", I'm willing to have a go at fitting it! I guess it would have to be glued on with Tiger Seal held with pop rivets until set then the rivets drilled out and the holes filled. The biggest problem is going to be getting some of the joining edges thin enough, ie in the doorshut and at the rear of the D pillar where the stainless moulding goes over the seam.
Steve
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 9:09 pm
by James467
How structural is the rear tonneau?
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 9:20 pm
by Carledo
James467 wrote:How structural is the rear tonneau?
Well it is and it isn't! In theory, EVERY part of a monocoque is structural, that's why it's called a monocoque!
In practise, some bits of the shell are more load bearing than others and for MOT purposes anything above the top of the sills and aft of the rear axle is fairly irrelevant. In any case, a well made GRP panel is near enough as strong as a (new) steel one.
I believe our own DF has made carbon fibre rear wings (as well as near enough every other panel, including the roof skin) for his latest project.
Steve
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 9:26 pm
by James467
Well I would say that yes you probably could be fitted.
If you do a google image search for MG Midget Lenham conversions you'll see that all of the outer rear panels cut off and replaced for a fiberglass rear section and roof.
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 9:31 pm
by xvivalve
Darren has indeed, but hardly monocoque any more, his roll cage is almost a space frame!
Unfortunately a 'test' article would require full commitment to the project; once a mould is made, it is made and that is the expensive part of the project!
With a welded steel panel the door shut poses a problem that GRP might overcome; that of having to fix the door flitch to the wing first...
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 9:40 pm
by Carledo
xvivalve wrote:Darren has indeed, but hardly monocoque any more, his roll cage is almost a space frame!
Unfortunately a 'test' article would require full commitment to the project; once a mould is made, it is made and that is the expensive part of the project!
With a welded steel panel the door shut poses a problem that GRP might overcome; that of having to fix the door flitch to the wing first...
What i was getting at, re the doorshut, is that the factory panel turns into the shut hole and is secured to the arch inside the shut. too thick a grp panel will leave insufficient space for the door, though looking at some of "our" cars, it might actually be an improvement, the gaps on my Sprint are HUGE! (but not consistent)
Steve
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 9:57 pm
by xvivalve
Yeah, I understood. The outside face of the GRP panel would be dimensionally accurate, so the shut line should be perfect, but as you say it would require skill to get the GRP flange down to steel thickness...
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 10:01 pm
by Mahesh
With further thought this seems to be a more important experiment than initial impressions of steel vs grp.
The fitment technicalities will be secondary to getting the initial design/dimensions correct to take in account vagaries of BL tolerances.
Is there an indication of costs involved ? and a car that requires an o/s panel ?
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 10:26 pm
by xvivalve
If the pressed steel originals coped with BL tolerances, then I'm sure GRP cast off a mould using a NOS plug should cope equally well.
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 10:28 pm
by xvivalve
Costs would depend on how many sections the mould has to be made from in order to be able to release each panel...the boot gutter is likely to complicate matters...
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 10:34 pm
by Mahesh
Sounds very interesting, with Steve helping out on the fitment, and minds greater in design than I, it looks like a viable proposition.
Is it a club project or personal.
Re: OS Rear Wing Availability...
Posted: Thu Mar 03, 2016 10:43 pm
by xvivalve
Mahesh wrote:Sounds very interesting, with Steve helping out on the fitment, and minds greater in design than I, it looks like a viable proposition.
Design inspiration often comes from the unlikeliest of sources...
Mahesh wrote:Is it a club project or personal.
Neither; without a NOS panel it is purely hypothetical. Unfortunately Mikey B wrested the one I had from me a few years ago
and it has now been used. The panel man has a s/h one I cut from a car many years ago that he uses as a pattern for the lower repairs, but from memory it has bits missing...
Re: OS Rear Wing Availability...
Posted: Fri Mar 04, 2016 6:56 am
by tony g
I think its a great idea, if it can work. Can the club funds be used to trial this out?
Tony
Re: OS Rear Wing Availability...
Posted: Fri Mar 04, 2016 9:44 am
by xvivalve
without a NOS panel it is purely hypothetical