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Some advice on using fibreglass panels

It has got to the stage now where the use of fibreglass panels is becoming commonplace. And not just for those looking for a lightweight body for drag racing, or some simple bolt-on flairs and spoilers. Complete fibreglass replacement panels are now available for fenders and bonnets (limited to only a few models), as well as for previously welded on panels such as front valances at rear beavers.

While many of these fibreglass panels have been made for the drag racing sport and they leave a lot to be desired when it comes to fit and finish. Rare Spares has been forced to produce and market some fibreglass replacement panels simply because making them in metal beyond our current capabilities. Our replacement glass valances, beaver panels and spare wheel doors for utilities and panel vans are very high quality, and the fit and finish is equal to that of a metal panel. We do sell some fibreglass fenders, for EJ-EH made by other companies.

We have even attempted manufacture fibreglass wagon tailgates for HR and HQ Holdens, but again, the prototypes were not accurate enough to put on the market. So, to date, we’ve limited our own fibreglass panels to those we can guarantee. That doesn’t mean we don’t sell other fibreglass panels, it’s just that we can’t really guarantee they fit all that well. It comes down to what you are willing to accept.

Fitting a fibreglass panel as a replacement for a welded-on metal one is actually easier than fitting a replacement metal one! Take the EH rear beaver for example. Remove the old damaged or rusty beaver and prepare the inner panel as usual. It’s a good idea to rust proof the inner panel at this stage, because the glass beaver will never rust again, so unless it is damaged in an accident, you will never have to remove it.

Then trial fit the fibreglass panel. Remember glass is strong and flexible, so it can be flexed into place. Some front valances and spoilers don’t seem to fit when you first try them on the car. They are actually made like that, and they have to be flexed into the correct position. This technique is used to give the panel extra strength and rigidity.

Often, the gap between a fibreglass panel and the adjacent metal is more than the gap would be if both panels were metal. This is the case with an EH beaver, on the side where the panel meets the rear quarter. This is done to give you enough room to successfully fix the glass panel into place, and to allow sufficient bonding surface for filler. Other glass panels have a recessed edge where they meet metal, and this recess is designed to give sufficient overlap for a strong joint.

Fix the fibreglass panel into place with PK screws or pop rivets, locating the fixing points about l5Omm apart and in hidden locations wherever possible. For locations where the fixings will be visible, recess the hole and use pop rivets, filling the recess to level before painting. For extra strength, you can use special fibreglass to metal glue that is available from most hardware and panel supply shops.

So, don’t be put off by the thought of having to use some fibreglass panels on your car. Remember also that once it’s in place you won’t have to worry about rust ever again.

From “How to Restore your Car Successfully”