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To fibre glass or not.......

Posted: Wed Mar 07, 2012 4:03 pm
by cadetchris
Both of my doors in Primrose are pretty shot at the bottom and it's time to fix/replace them.
With hardrian panels now gone and the other suppliers not having any replacement door skins (I want to fix them properly, not just part of them) I have looked at the idea of fibre glass doors instead.
I like these as they they won't ever ever rust and for the price of a door skin, I can get an entire door.
What are people's opinions on glass fibre doors?

Re: To fibre glass or not.......

Posted: Wed Mar 07, 2012 7:32 pm
by C6Dave
Whilst steel doors don't offer a lot of impact protection, glass fibre offers none

There are images linked to on site http://www.flickr.com/photos/46862234@N03/ of a car being repaired following a frontal impact and the fibre glass wings that had been fitted simply shattered.

Any additional strength steel ones may have provided was not there, so the impact was all taken by the inner wings/engine bay floor

Personally, I wouldn't replace any panels on a car like a Morris Minor with fibre glass ones, but it is your choice

Re: To fibre glass or not.......

Posted: Wed Mar 07, 2012 9:00 pm
by dp
What if a layer of kevlar or three (expensive I know) was added to the inside of the fibreglass door skins - or many layers of fibreglass? Or is there a simple means of adding impact protection greater than the original steel doors?

Re: To fibre glass or not.......

Posted: Wed Mar 07, 2012 9:09 pm
by cadetchris
Ouch, I knew they where a little fragile, but Matt's car (the one pictured) is quite an extreme case. A side impact of any variety on a Morris is generally bad.
Anyway, I digress.

Re: To fibre glass or not.......

Posted: Wed Mar 07, 2012 10:06 pm
by millerman
Fibre glass door skins are available. Try JLH :D

Re: To fibre glass or not.......

Posted: Thu Mar 08, 2012 8:52 am
by ratrodmog
Like you say, a side impact onto metal doors will offer little protection but fiberglass will be even less. If I were fitting fiberglass doors then I would bond in some reinforcement bars (2x1" box section) or even better make an internal skin from a carbon kevlar composite weave.
Am I right in thinking they are only available for 2 door vehicles?
As an alernative to adding material to the doors why not fit a roll cage and door bars to make an internal structure? This would obviously only suit a specific style of car i.e hot rod/ race car etc, this is what I have done and feel a lot safer.

Re: To fibre glass or not.......

Posted: Thu Mar 08, 2012 11:31 am
by customjob
Hi all, to fibre glass or not, ok lets stand back for a moment, almost all modern cars these days use a composite fibre material for front and rear panels or alloy composits, behind that is a progressivly collapseable zone. Fibre glass wont bend and distort like steel, but will absorb and disapate shock through itself better than steel can. Thus allowing the inner wings and front panel to collapse better. Ok more damage will result and a higher chance of right off but may be a lesser chance of impact velocity injury to the body wearing of seatbelts also helps.

If you were to also use a Glass Fibre bonnet that would then give a greater area for impact shock to disapate through, allowing movment energy to be absorbed by the inner strucure, I grant you that your front bumper wont do much appart from under run the rear of the car you just hit and lift it up, which could be an advantage as movement energy would be carried forward to that vehicle thus reducing energy coming back into your car as both vehicles are moving together in the same direction and not coming to a sudden stop.

Glass fibre or composite doors. iIwould deffinately say no way from the front bulkhead to rear bulkhead you want it as strong as possible. the car was not designed with composite materials, you have a side on impact with a steel door you come out at best say with broken bones you take that steel away and fit composite where is the strenght in the A post and B post you probably wont be coming out at all.

Door bars, again a bad idea for moggie doors steel or composite, the car was designed for active or passive saftey. You have an impact heavy enough to move the body forward or back that door bar could push through the front or rear edge of the door and even entre into the A or B post thus jamming that door shut.

Sounds dramatic i know, door repair are available good second hand doors can be found.

Re: To fibre glass or not.......

Posted: Thu Mar 08, 2012 12:28 pm
by Alex'n'Ane
Would it be possible to fit and bond just the lower 'repair' sections, ie bottom 1/4 of door and underneath, and have these done in fibreglass, In a similarish way to that which has been used to fit the fibreglass door skins in this thread?
http://morrisminorowners.co.uk/about2402.html

Re: To fibre glass or not.......

Posted: Thu Mar 08, 2012 8:55 pm
by linearaudio
Regarding Matts car- the bonnet must have absorbed a fair clout to put that horizontal crease across the front- amazing it didn't shear the hinges off, as some seem keen to mention will happen in any severe frontal shock! I reckon the wings probably took their fair share of impact absorbing before displaying very predictable failure points. But as for doors?
Are there any people on here (ex Lotus/TVR/Reliant etc) with design experience of g/f versus steel in a flat(ish) form? Would the g/f neccessarily be weaker than steel?

Re: To fibre glass or not.......

Posted: Fri Mar 09, 2012 7:24 am
by kennatt
well there was once an article in slice mag(relient owners club) and it was stated that there had never been a fatality in a relient scimitar car,all glass fibre,but and its a big but, the relients ,not talking about three wheeler and kitens,the big ones like my scimitar GTC and the other large ones.Have a massive chassis,with the body sat on it,so I suppose the body acts like a crash helmet .the only problem with fibre glass is that in a minor shunt,it shatters and need extensive work to repair,where as steel bends and you can knock it back into shape so who knows whats best.Dont have a problem with rusty doors though :D