GRP repair
Author
Discussion

ohidunno

Original Poster:

506 posts

301 months

Monday 28th March 2005
quotequote all
I have managed to damage the bodywork around the front indicator recess on my Chimaera. There is damage to a depth of about 5mm and the affected area is approx 70mm x 70mm.
The rest of the car is pristine as the car had a front end respray about 10,000 miles ago. So I was considering effecting a home repair, with a view to having the car resprayed in a couple of years when the front end will have collected a few stonechips.

I have used body fillers on old bangers years ago, but am far from experienced in this type of thing. I have a few questions:

1. do you think this type of DIY job is worth considering
2. what is the best filler to use
3. do i need to attend to this repair quickly? Is moisture getting into the exposed GRP going to cause problems?

parrot of doom

23,075 posts

263 months

Monday 28th March 2005
quotequote all
How did you do it?

gefopsman

260 posts

268 months

Tuesday 29th March 2005
quotequote all
I would suggest getting the repir done very quickly as moisture ingress will undermine any susequent repair.

The best method for repair would to to remove as much of the loose fibre as possible and replace with fibreglass matting soaked on resin. This will entail sanding back to capture the full extent of the damage which will be more than is immediately visible.

Matting should be used to build back to almost the height of the original finish. P40 fibreglass repair can be used then to fill an deep areas left/missed.

Once sanded back, standard body filler can be used to complete the repair which will then need to be primered using two pack acrylic primer. Any other primer could lead to problems later on.

19560

14,332 posts

287 months

Tuesday 29th March 2005
quotequote all
gefopsman said:
I would suggest getting the repir done very quickly as moisture ingress will undermine any susequent repair.

The best method for repair would to to remove as much of the loose fibre as possible and replace with fibreglass matting soaked on resin. This will entail sanding back to capture the full extent of the damage which will be more than is immediately visible.

Matting should be used to build back to almost the height of the original finish. P40 fibreglass repair can be used then to fill an deep areas left/missed.

Once sanded back, standard body filler can be used to complete the repair which will then need to be primered using two pack acrylic primer. Any other primer could lead to problems later on.

IMHO a good summary. Note the first sentance, capiliary action means that once moisture is in the strands even an oven cannot remove it. Effected area is likely to be bigger than you expect. I would use aluminium mesh fixed below as permanent formwork.
Note also
gefopsman said:
Matting should be used to build back to almost the height of the original finish.

I would read this as to within 1mm or if you use tissue then to within 0.5mm.

ohidunno

Original Poster:

506 posts

301 months

Wednesday 30th March 2005
quotequote all
Thanks for the input.