Hi All

I have to make a bulge in my aluminium bonnet to miss the cam covers and thermostat housing on my Locotec (Zetec engine). Bodywork is not, normally my area of expertise! I was going to make it out of fibreglass but don't know how easy it is to bond fibreglass to aluminium and then how to fill etc..

The attached picture shows my problem (the other patched hole is where the air filter used to protrude when the car had a 1300 crossflow)

Any help would be much appreciated.

Wyn
Rescued attachment P1010040.JPG

I would design the bulge with an internal flange to allow you to rivet/blot through the bonnet, hiding the rivets inside the bulge. You could also put some rubber bead arounf the edge.

Flanges are good

little ascii diag of what I mean...
___
/_ _ bulge
--- --- bonnet

would make the mould fairly tricky to make/release though.

edit - dammit, spaces not coming out in diagram.

edit - tried it improve slightly, the hole in the bonnet and bulge are only one space wide, hopefully its enough for you to see.

[Edited on 22/3/2004 by GO]

[Edited on 22/3/2004 by GO]

Sikoflex or any other PU should do it after you'd removed the paint off of the Ali.
Cheers,
Bob

JB Weld would be less affected by the heat

Thanks for all the responses guys. I can see a long night in the garage.........

Before you make an aluminum/fiberglass concoction, you may want to consider using your aluminum bonnet cover as a mold for a single fiberglass piece.

I don't know if it would save any weight, but it would most likely look a lot cleaner than something that is glued on...

If you do want to attach a fiberglass piece to the aluminum, I would suggest pop rivets and some bondo and a goos sanding to smooth the whole thing out.

-MR

Hi

I have just brought a fiberclass bulge from red line engineering (C*****ham) do do the same thing on my car, not sure if it is the right size for you but it is quite big. £20.00ish

Dave

Hi

I have just brought a fiberclass bulge from red line engineering (C*****ham) to do the same sort of thing on my car, not sure if it is the right size for you but it is quite big. £20.00ish

Dave

Thanks Westdown. Do you have any pictures or a part number?

Who was it that suggested a fuel tank from a motorcycle??? Am toying with this idea, any pics, or advice on how to fix to bonnet? Some of the above ideas coiuld work, like a flange rivetted on.
Am also thinking of using the petrol cap from the same source, anyone else done that? Would use the cap plus cut the surround to mount on the back panel. Anyone put a filler on the side behind the rear wheel arch?

You could just make you bulge and fibreglass it on from underneath (making sure the ali is weel roughed up of course). Any of the car body fillers (P40 maybe?) would be suitable to blend it in if you wanted to and they are pretty crack resistant if you dont need to bend them too much. I think you could make a neat job of it like that...but i stand to be corrected!

Cheers
David

Actually, a quality epoxy would be sufficient to bond fiberglass to the aluminium. Just be sure to scuff and clean each surface well and find one with sufficient thermal properties (250F or so Tg). Otherwise the one piece mold mentioned earlier would be a pretty good idea, but would still require the higher temp epoxy. Polyester/Vinylester resin would probably sag after time due to heat.

Stuff the glassfiber beat a bulge out of ali.
Make a mdf ring the size you requre x 2
cut ali larger than required and screw the bits of mdf together clamping the ali between them. You could use your sand blaster on the rear/underside to stretch the ali to a bulge. You could use the panel beaters hammers with a shot sack on the bottom to beat against machine mart has a kit for 19 quid. To fix these panels to the bonnet some countersunk rivets (small) and some silkafex or other adhesive. This should work no bother. Terrapin uses a similar method to form his rings with no problems.

Someat to tink about....

You could allways use the "concrete mold".Look for a plastic container with a bottom shape you like.Cut the bottom out to needed height and fill this with concrete with fine grade grain.After drying leave the concrete in the mold and flip the whole thing upside down onto a small sheet of mdf covered with plastic.Make a "wall" around the mdf of board to a height of top of mold + 2".Optionally you can fill the edge between the mold and the mdf with bodyfiller to give it a smooth radius.Fill the whole thing up with the same fine grade grain concrete and let dry.
After curing remove the plastic container and you have a perfect male/female mold.

Tetrion household filler mght do the job if you don't want a bag of cement hanging round to go off. Is that a NTV in the background? I think I recognize that swingarm. I have a fibreglass bulge that someone gave me, it's from a bus and the grandkids use it in the sandpit as a mould. I'll post a picture in a bit.

Dear All

Thanks for the tips - when I get time.......

Peteff - yes it is an NTV - rides nicely and my wife liked being on the back of it (until she got pregnant!!)

On the back of an NTV?? Rusty

Not on the back of the NTV, and not in the MX5 we bought her the same day he was conceived!!

Are you that good with the missus?
Never got anything!

Sorry about ressurecting this old thread ......Has anybody tried beating a bulge (oo er!) from ali? Would the ali have to be a certain type ,or just any type ,annealed? does it work with ,say,1.6 thickness ,or does it have to be thinner .? so many questions!!!! ROD