22 replies to this topic

[MotorBoatMyGoat]

I'm having problems with a leaking sunroof. One of the solutions I've come up with is to get a carbon fibre roof. I'm aware this has been done however to save on costs I was wondering if it would be possible just to stick the carbon fibre roof skin onto the current roof?

Would this be possible/has anyone tried this? Or am I better off coping the old roof off?

Any help/experience would be greatly appreciated.

[59 Speed]

I don't think you fully remove the old roof skin in the first place. I think you leave a strip of the roof around the edge for the carbon to be bonded to.

[mini93]

The process normally is to leave a 2 or so inch gap around to bond the panel on to, however its a problem being you are going to be removing some of the shells structural integraty, It could be replaced with a rollcage bit this supplies other flaws you may want to avoid.

 

Another thing to consider is how the roof is made, its like stacking 2 bowls together, the shape means they dont sit perfectly within one another unless its designed like that. If the roof was designed to occupy the space where the original roof would occupie, trying to drop it over the top would mean it wont sit correctly.

 

That said, I've got one for mine!

[kezzkitkat]

Ive seen it been done by sticking on top look daft in my opinion like said 2 inch all the way round and the rest cut out however if you want to lower cost d consider not bothering with a cf roof
I would take the sun roof out and seam weld a patch and do some old fashioned panel beating however the risk that the panel can distort so some people do a complete roof with 3 inch of the pillars but to be honest its down to experience and confidence which way you go
It not the easiest repair first one I did was at 15 took me good few hours to get the shape right

[MotorBoatMyGoat]

Have you attached the roof yet? If so how did you do it?

I don't plan on putting a roll cage in. It won't fit with my plans for the interior.

My mini is having some minor bodywork and a total respray. The sunroof is causing me issues as it's a cheap aftermarket one the previous owner put in. When I spoke to the bodyshop they said they wouldn't really want to cut it out, weld a piece in and use filler as it may be a poor finish. They suggested putting a new roof skin on but said it'll be a big job. A mate suggested a "roof cap" (being the carbon roof) which I thought seemed like a good idea and looks epic on the 72 calibra engined beast on a different thread.

I don't mind spending a few quid as I want a show car standard finish. Just fishing for ideas

[kezzkitkat]

Is there no local person on the forum that cann help im certain some one will do it for a reasonable price
And dosnt suprise me about the bodyshop there a business and want to get it out as quickly as possible also quite a few panel beater tend to rely on body filler there a few I work with who do so

[mini93]

I havent attached it yet, I havent collected it yet! But a good bonding agent like tiger seal of sikaflex (of the various types available) would be suitable.

 

being generious with the bonding stuff, strap the roof down lightly but firmly while the bonding agent cures.

 

Bonding panels can be very strong! but the strength only comes when the panels are designed to be. A mini roof is designed to be welded contruction. Some would argue its just the same as the factory fit webasto roof option such as fitted to the open classic. But it is recomended to have a cage with a composite roof.

[MotorBoatMyGoat]

I'm located in Reading and work in Oxford. I'm currently working my way round the local body shops for quotes/ideas. I don't mind travelling for good workmanship if you know of anyone.

[Icey]

I would take the sun roof out and seam weld a patch and do some old fashioned panel beating however the risk that the panel can distort so some people do a complete roof

 

Risk? I'd say it's guaranteed to distort. It's a large, single ply panel pressed into compound curves. You'd need to form the new panel into the correct curves and then weld it using as little heat as possible.

 

The skill and effort involved with getting that done with little distortion puts it out of reach of most DIYers (I'd have no chance). It's not impossible, it just very difficult and you need the right kit.

 

While it sounds drastic, if you don't want a sun roof, personally I'd reshell or change cars. Roofs are a nightmare to work on.

Grafting on a carbon roof could be a viable way to solve this but unless the roof was made to a high standard and bonded using the correct materials I'd want to fit some extra reinforcements. Composites are good but they need to be made correctly for the application - a simple 'skin' isn't going to truly replace a steel roof.

[Cooperman]

In terms of structural integrity, the roof skin does very little as the roof surround takes most of the loads.

It is very simple to fit a new roof skin and when I rolled my Cooper 'S' on an historic rally I fitted a new metal roof skin in a day, then painted it the next day.

A carbon-fibre roof skin would be fine, but the original must be cut away to leave around 3" of the metal roof. Then bond the carbon skin on using Tigerseal or similar. You might need a 'kiss' of body filler around the edge before priming & painting, but so long as the carbon panel 'nests' nicely into the gutters it will not need much.

The biggest problem would be the head-lining as it should really be removed to avoid risk of tearing it when cutting the roof panel. But if the car had a sun-roof there will be a need for a new head-lining anyway, so the screens will be coming out to fit that, which helps with clamping the new roof to the metal edge of the old one whilst the adhesive cures.

Under no circumstances fit a carbon skin on top of a metal skin as moisture will be trapped between them and the old roof will rust out.

[midridge2]

Can you use body filler on carbon fibre?

[Cooperman]

Can you use body filler on carbon fibre?

 

Can't see why not. You can paint C-F with no problems and I'm sure normal body filler would adhere to C-F.

[59 Speed]

Can you use body filler on carbon fibre?

 
Can't see why not. You can paint C-F with no problems and I'm sure normal body filler would adhere to C-F.

Even if it's showing the weave?

[kezzkitkat]

You can paint over carbon but you cant bake it at high temp it has to dry natural thats the main problem as for filler not to sure I've always used resin, patches but I only repair motor cycle fairing that are cf
And abit extreme to re shell just for a sunroof depends what tool you got yes your right a diy who's first attempt may not be able to aswell as not having tools to do it but doing a roof is not a bad job quite intense though
Rather do a rmini roof that a side impacted vehicle know from experience

[Cooperman]

I've never painted C-F, but race cars are made from it and they are always painted.

I guess that a high-build primer would be sprayed first, maybe a few coats, then 'nibbed' back and the top coats applied.

However, it is also easy to weld a new steel roof skin on which takes about an afternoon, after spending the morning cutting the old one off and grinding back.