Headliner restoration - removing the sponge [Archive] - SaabCentral Forums

: Headliner restoration - removing the sponge


RickyS
20-07-08, 06:05 AM
I'm using stiff nylon rotary brushes on an electric drill to remove the sponge layer from the headliner biscuit. The C pillar trim came out OK. But the headliner biscuit is different.

Removal of the sponge layer is no problem, but it leaves a rough glue layer. Do I need to remove this glue layer?

I read that some folk have applied PVA glue over the whole of the headliner once all the foam is off. Did you remove the old glue layer first? How long does the PVA take to dry out, and how much will I need?

TooMany2cvs
20-07-08, 09:21 AM
I'm using stiff nylon rotary brushes on an electric drill to remove the sponge layer from the headliner biscuit.

Sounds a bit harsh to me.

I read that some folk have applied PVA glue over the whole of the headliner once all the foam is off. Did you remove the old glue layer first?

I got it fairly smooth, but not mirror-like.

How long does the PVA take to dry out, and how much will I need?

Overnight, and "not much". I put a good slug of PVA wood glue into an old jamjar, watered it down to the consistency of single cream, then painted it on. I've got edges which are delaminating - I've given those a really good soaking with PVA, covered in cling film, and clamped with some bulldog clips using some thin strips of wood to spread the force. Seems to be working. Where repairs need to be done, I've been building up with strips of newspaper soaked in PVA. Where serious repairs were needed (behind the interior mirror had completely gone AWOL), I built a framework up with thin copper wire (one core from some domestic solid-core lighting gauge twin-and-earth wiring) The PVA's always been watered down to that single cream consistency - it's just too thick to do anything with as it comes out the bottle.

85spgATL
20-07-08, 12:12 PM
Removal of the sponge layer is no problem, but it leaves a rough glue layer. Do I need to remove this glue layer?


I did not. Anyway, if your puttig another pad on, it will look fine.... I used quarter inch headiner foam from the frabric store.

http://i6.photobucket.com/albums/y222/dudeimarobot/SAAB/inteiror2.jpg

85spgATL
20-07-08, 12:20 PM
Removal of the sponge layer is no problem, but it leaves a rough glue layer. Do I need to remove this glue layer?


I did not. Anyway, if your puttig another pad on, it will look fine.... I used quarter inch headiner foam from the frabric store. Looks smooooth

RickyS
21-07-08, 12:44 AM
The stiff nylon cup brush was OK provided you go carefully on the curved sections and don't try and remove the glue layer. A soft nylon cup brush might be better, but I don't have one to try.

Anyway I managed to make a few depressions in the biscuit which I think will show through when the lining material is down (I'm using foam backed lining material about 1/8 inch thick), so these will need to be filled. What to use? I'm thinking of using some stopper filler and sanding it flat/level.

All the sponge is now off. Used a DA sander to get rid of the last of the sponge. OK to use a DA on the flat, but not a good idea on the curved areas.

I'm going to use PVA on the weak areas around the edges and fittings, maybe over the whole biscuit. I've used wood PVA before. Will PVA fill in the depressions or just soak in and harden the existing depressions?

euromobile900
21-07-08, 12:58 AM
In my experience, PVA alone will not work as a filler. It will just soak in and harden the depressions. I used paper mâché on my headliner biscuit where it had failed around the sunroof and by the mirror, and also to mend it back together after I cracked it in half trying to get it out single-handed. After my high school sculpture class, it seemed like the ideal medium to use. Surprisingly tough. Paper mâché has potential to fill in dents too, but this is a little more work since you have to cut the pieces of paper up really small and then lay them just right. I'd advise sawdust/PVA mix.

Also, I did remove the glue layer (by hand, with a putty knife), but I took some of the biscuit with it, and it was a bear of a job, especially sanding the biscuit smooth afterwards. I like to think it saved me having to do the job again soon, but I really have no idea.