If it's that old washing-up bowl plastic you have a problem. The best way to graft pieces in have found is to spot weld it- use an old soldering iron to fuse the plastic together on the inside. Otherwise what I have done is to roughen up the gluing surface with coarse sandpaper and apply 'brush-on' superglue liberally so that it soaks in. Then you can glue new pieces in as per normal.
To fix the wheel arches, I would trim everything back to a clean shape, then cut some plasticard roughly to fit. Glue/weld it in position, then back it up with another bigger piece on the inside that covers the joint. Fill all the gaps with a fillet of body putty. Then you can file and sand it to the correct body contours and simply recut the wheel arch to the correct profile.
Then you have the problem of painting. Most stuff doesn't adhere well to the soft plastic, but again, I have done it by papering everthing and 'clear coating' with brushable superglue. Otherwise there are special paints available in the US that have been mentioned on the forum, but I havn't got hold of any myself.
But if it's hard plastic, all you have to do is fill the arch with plasticard and recut, as above!
To fix the wheel arches, I would trim everything back to a clean shape, then cut some plasticard roughly to fit. Glue/weld it in position, then back it up with another bigger piece on the inside that covers the joint. Fill all the gaps with a fillet of body putty. Then you can file and sand it to the correct body contours and simply recut the wheel arch to the correct profile.
Then you have the problem of painting. Most stuff doesn't adhere well to the soft plastic, but again, I have done it by papering everthing and 'clear coating' with brushable superglue. Otherwise there are special paints available in the US that have been mentioned on the forum, but I havn't got hold of any myself.
But if it's hard plastic, all you have to do is fill the arch with plasticard and recut, as above!
