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A Fibreglass repair on a Lotus Elan without the panel in situ

We wanted to restore the glassfibre wheel arch of this lotus elan, usualy repairs done to fibreglass panels are easily carried out by removing the panel for easy access, but as in the case of this panel,  the left hand front wheel arch is moulded to the right hand wheel arch as one continuous unit running also under the engine, we wanted to carry out the repair without having to remove the whole fibreglass panel and engine.

 First of all we need to create a forma by taking a mould from the wheel arch on the opposite side of the car. The lay-up needs to be thin and flexible enough to turn inside out so we can transfer the contours of the right hand side wheel arch to the left hand side.

Make sure all the areas are masked off to prevent Polyester Resin/Gelcoat from running of into unwanted areas.

Apply several coats of PVA Release Agent to the panel letting each coat dry in between coats.

Once the last coat of PVA is dry lightly apply a mould release wax, such as Meguiars M08 or TR 102. This just makes it slightly easier for release we have found combined with the PVA release agent.

Lightly buff off the mould release wax before it dries. .

Cut strips of plain weave fiberglass tape enough to cover the arch with 1 layer, here we used 175g plain weave tape.

Have your fiberglass cut as a kit ready before mixing any resin.

Refer to our catalyst addition chart on our labels and mix the required amount of resin with catalyst.

Wet out the fiberglass cloth with the catalyzed resin.

We then placed the wet out cloth onto the waxed area over lapping the joins by approx 2”, then stippled the cloth with a brush and expelled any trapped air then left the laminate to cure.

Once cured the laminate is sanded to flatten down any rogue Glass fibre strands.

Then the laminate is lightly wiped with acetone to remove dust.

The GRP laminate is removed and should be flexible enough to turn inside out and fix to the damaged area.

The forma should easily turn inside out to cover the area where the original laminate is missing.

The forma is taped in place using masking tape.

We then made a couple of ribs to tape to the area which had a bit of sag to it. These ribs were made by moulding another thicker laminate from the opposite wheel arch and cutting 1” strips from the laminate to tape onto the areas of the forma to hold its shape. Once these ribs are in place and the forma looks nearest to the correct shape add more layers of cloth on top - approx another two layers.

Remove the Forma once it has fully cured and mask off any areas which you don’t want any dust or resin running into.
Tidy the fiberglass edges of the damaged laminate, and key all areas to which the fiberglass and resin is to be applied and wipe down lightly with acetone.

From the underside re-enforce any loose areas of the original damaged panel with fiberglass and resin, when laminating an upside down area fiberglass tends to not hold its own weight once wet, so use a 100g chopped strand matting as this consumes less resin and will not fall off when wet out with resin. Add 3layers making sure each layer is 2” larger than the last

Add again mold release agent and wax to the inside surface of the Forma as we did earlier to create the Forma.

The forma will be fixed to the damaged area by screwing a series of self tappers through the forma into any of the undamaged original laminate. 

Screw the self tappers at least 1cm in from where edge of original laminate is.

This picture shows the view from inside once the forma was screwed into place; the self tappers should pull the edges of the original laminate up against the forma.

Now the forma is in place catalyze a batch of Polyester Gelcoat, we used grey nearest to cars original colour.

Apply the Gelcoat with a brush to the inside of the forma and slightly onto the original body work and leave to cure.

Now catalyze a Gel-coat filler and using a squeegee apply a layer on top of the cured Gelcoat approx 2mm thick and leave to cure this will give a thick surface to the panel if rubbing down is required later.

Apply a couple of layers of 100g matting to the inside of the forma using catalyzed resin and leave to cure.

Once cured, build up another 2 layers of 450g chopped strand matting.

Once the laminate has cured peel away the forma.

As you can see this has left us with a good shell to build up on.

We applied body filler to fill in any slight imperfections and to start getting the original shape back

This model of Lotus has two distinct profile lines running down the original panel so to recreate this we cut two strips of sheet wax and ran the outside edges along where these lines should be, once in please we blended car filler up to the level of these strips and left the filler to cure.
Once the filler had cured we peeled away the wax which left two 2mm steps which blended to nothing down each side of the panel, then we filled the middle with more filler giving us a good shape to sand down and carve into the original profile.

The edges of the wheel arch needed to be grinded back to line up with the bumper, before doing this we built up the area behind with a fiberglass filler to prevent grinding back to nothing.

Now we move onto the damaged bonnet and repair that hole.

The damaged edge is filed to a wedge tapering of towards the painted surface of the bonnet, we also sanded the surrounding area to give a good key to achieve the best mechanical bond possible we then wiped it down with acetone.

Cut a sheet of 2mm self adhesive wax larger than the hole.

The wax should be at least 2” larger than the damaged area.

Push the wax firmly around the edge of the damaged area.

Check that the wax is firmly consolidated to the edge of the damaged area, then mix a batch of catalysed Gelcoat.

Apply a catalyzed Gel-coat to the wax within the damaged area.
Cut 4 pieces of fiberglass (450g c.s.m) the first two should fit exactly into the damaged area then should be followed by another piece slightly larger than the damage and the next again slightly larger than the previous.
Wet the Gel-coated area with catalysed resin, then lay the first piece of C.S.M. on top then wet out with more resin
Consolidate the matting using a paddle roller to expel any trapped air and flatten down the fibres, repeat this process for the consecutive layers.
Remove the sheet wax to reveal the repair.

Rub down with wet and dry paper to achieve a smooth finish, using 240 grit is sufficient enough in this case.

The repaired wheel arch was sealed with a protective coat of epoxy resin this creates a harder wearing shell over the area which was built up with polyester car filler.

The car was then sent to be re-sprayed and is now restored to its former glory.

We are not a body shop and this was a favour as we are very helpful guys here, please do not bring your damaged fibreglass car to the workshop :-)
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