Roof lining repair time

So I have a roof lining that needs repairing in places and possibly strengthening too. Is paper mache really a good solution? Or is fibreglass a better solution. Or something else?
I'm not looking forward to this as it enjoys resting on my dining room table

 

Fibreglass. There's a bit of strength in it.

 

That's my thoughts too. And on the back side too.

 

I would only apply it to the rear tbh.

 

I have used fiberglass in the past, it does work, as Tristan stated use it on the rear surface and build it up in layers its still very fragile though.

 

When I did mine I used superglue in all the cracks. The material responds really well to it. I then use car body filler to fill all the dents and holes and wider cracks (after using copious amounts of superglue). The superglue really seals the spongy surfaces well too, then the filler bonds really well. After all that I could lift it with one hand and it was very strong.

Here is my thread.

https://clubgti.com/forums/index.php?threads/headliner-refurb.290444/#post-2491939

I used a lot of superglue, nearly 3 bottles of the industrial stuff from Toolstation. I can't stress enough how well it worked. Try a bit and see for yourself.

https://www.toolstation.com/gp-super-glue/p16435

 

Just watched the guy doing the refit. Hives me confidence. Thanks for the input gents

 

I re-did mine recently after the first attempt with “hi temp” upholstery adhesive failed with the car left in the sun on a hot-ish day, despite removing the residual foam both surfaces. It was ok until that hot day, then sagged again. This time I used super glue in the cracks and strengthened it, where necessary, with aluminium speed tape. Used super glue to bond the lining material to the backing too. Didn’t get a perfect finish because this time I didn’t remove the flaky foam and some sort of chemical reaction was going on that gave out a fair bit of heat. It’s not perfect but don’t think it’ll sag again. I didn’t want to use fibre glass cos it stinks and wasn’t sure how long that smell would linger right above my head.

 

It goes away alright. After a week or so.

 

Did my 87 GTI sunroof with fiberglass as I was a boatbuilder for a fair while in NZ and Australia,the liner came out in many sections,covering just fell off after removal as the foam backing was dust.
Built a setup repair table and made wood packing blocks to line up the broken pieces and make sure everything was square,fiberglass "hot tacks" applied to the back side after grinding the black moulded layer a bit with is scary because it can just blow apart rather easy.
The secret to using the fiberglass is the laminate the joins and broken area's so you don't create "hard spots" as the shell will crack either side if you don't,this will occur when you turn it over or move it around.
Spent a lot of time removing old inner foam and glue and after trying various things I settled on acetone to melt this sticky shit.
Material chosen by trimmer was black Mk4 Golf which he imports from Europe,has to foam already bonded on to it which he mentioned provides a better finish surface after gluing on.
End of the day its the sort of job you want to get right first time,cheers.