By Damien Reid

Looking for a quick fix for minor scratches, scrapes and rust which will stand up over time but not cost you a fortune?

Fibreglass filling is one way to repair bodywork quickly and easily.

Mix only as much filler as you can use in a few minutes because as soon as it starts to harden the process is irreversible and cannot be manipulated, so before you begin, make sure the area you want to fix is free from all dust and grease.

As each brand of fibreglass filler is slightly different, be sure to read the directions especially those relating to the ratio of hardener to mix. Combining too much hardener will force the filler to set too quickly before you've finished with it, while using too little will allow the fill to sag and run.

Mix thoroughly until the colour is the same throughout, then use a trowel, spatula or similar tool to apply the coats. Always use a little more than you think you'll need as it will need to be sanded back to provide a smooth finish.

With fibreglass the result is light and fast compared to other metal-based fillers and it's also partially moisture resistant which is great for problem rust areas as it reduces the chance of rust re-occurring around the same place.

To apply, mix roughly 50 parts of filler to one part hardener and knead on a mixing board until it becomes a smooth consistency. This will iron out any air bubbles in the mix and never use cardboard as your mixing board as the filler will absorb moisture, air, oils and particles from the cardboard which will erode the filler composition.

Remember to mix small amounts of around 200g at a time and press it hard into the cavity to ensure no air gets between the fill and the panel. Allow each coat to dry for around half an hour and keep building small layers of no more than 3mm in thickness until the repair is slightly above the panel surface.

While small scratches and scrapes can be filled with fibreglass applied directly to the surface, larger problem areas including rust holes require a fibreglass patch or bridge. This gauze-like sheet spread across the surface gives a strong base to apply the body filler, ready for sanding and paint.

If you have any questions concerning fibreglass filling, see your local Autobarn professional who can advise on the best treatment for your car and the type of work required.