Rear Guards. Not symmetrical.

[Fred W.]

Hi All

Can any of the fiberglass experts on the forum help me out here?
I am in the middle of making my own rear guards (flairs) I have made the plugs and a set of moulds from the plugs. The moulds are close to being symmetrical but not perfect and I have a little bit of asymmetry. I dont want to go back and change anything to do with the plug and make a new mould.
Can I make the new guards, mount them on the clip and then 'build' up layers of glass on the outside of the side that is not as 'full' and if this is OK what are the best techniques for this. The difference is not that much may be 10mm but its enough for me to want to do something about it.

Thanks. Fred.

 

[Fred W Ballinger]

Hi Fred

Any thing is possible, and you could do what you describe, although it would make that area very heavy.

I would first bond on some polyurethane foam, over thickness, and then shape that back to say 2 or 3 mm under the profile you want. Than layup some matt over that, sand, and finish with filler.

Something like what I did in the pics below.

Cheers

Fred W B

 

[Fred W.]

Hi Fred

Thanks for the input its good stuff. I guess what Im looking at here is the bits of wood are clamping the foam good and proper for gluing and then your shaping it. Question, can you tell me what you are using to shape the foam with and at the risk of sounding a bit clueless what exactly is polyurethane foam. What differentiates it from polystyrene foam.

Thanks. Fred.

 

[Fred W Ballinger]

Hi Fred. (one of us has to get a nickname )

Yes, the wood and screws are to clamp the foam on as the glue dries. I use polyurethane wood glue to stick foam to foam and to wood. You would use Resin to stick the foam to GRP.

Polyurethane foam is used (among other things) for insulation, and unlike polystyrene is reistant to resin. You may be able to get it (as insulation sheets/blocks) from builders merchants or a big DIY store. It is made from two liquids that when mixed together solidify and swell up to foam the solid foam. (As used for race seats etc). You may also be able to buy it in this form.

I see you are in Adelaide - if you know anyone in the surfer community ask them to direct you to a surfboard "shaper", they use Polyurethane foam as the core for surfboards and as you only need a bit you could beg some offcuts.

The foam can be easily cut with an small ordinary hand saw, I rough shape it to size with a Stanley "surform" tool, and do fine finish with 80 grit paper on a block. It sands very easily.

I guess you do have a profile guage? - very usefull

Cheers

Fred W B

 

[Fred W.]

Thanks again Fred.

You have my respect for the work your taking on there. You dont have to be that much out from one side to the other for it to be noticeable even if its only you who can spot it easily. That bit of kit on the top of the left guard is my home made contour gauge made out of drinking straws. Naff !

I thought I would put a post up letting people know that if they have thoughts about doing some similar sort of work on their car, be warned that although the work is very doable it will be a fairly lengthy distraction from the mechanical side of the job and you almost certainly wont save any money. My reason for going ahead with the work was to have a go at altering the shape a little to add my bit of artistic license. No guarantee it will all turn out a raging success ascetically but Im having a go anyway.