Fibreglassing advice

**Bert** · 7th May 2006, 17:43

Originally Posted by Mattzxr750

that foam spray is not a bad idea. I was surfing the net on this topic and came across this site. they were making a fibreglass shell of a solar car.

and they made a foam model, sprayed it with gelcoat. then covered it with foam spray.

the out come was pretty good so when i make a new rear end for my bike im going to try that with so of the idea's in this post

THat my one good idea gone of the year.:slap:

**Mattzxr750** · 7th May 2006, 20:52

dont worry too much youll have another next year

**classic zed** · 7th May 2006, 21:01

Easily carved to shape, then a thin layer of glass, and finally primed, sanded, primed, sanded and so on until they are perfect then you can make the mould.

The ones pictured was built on a 650KTM for the Power Rangers series.

First pic is the finished foam, Second is the main body glassed and ready for primer, and finally the finished bike.

Two were produced one red and one green.

**sprocket** · 7th May 2006, 21:58

OK....my 2 cents

Mould Making 101

- Foam (if you intend on modifying the article) Article being the origional Fairing
All you do is Ados on blocks of foam and shape it to how you want it to look, with a speed file and sand paper

- once you have the desired shape that you want you then glass the foam with a single layer for E450 chopstrand matt (just the foam and maybe 30 - 40mm onto the article)

- Next we fair the article normally, you would use a polyerster resin with q-cells(easy to sand ) but car bog will do as its polyester based (tip when sanding it dont leave it for to long as its a bastard to sand when its fully cured, just let it tack off for 20mins then sand it with some sand paper )

- The secrect to making a good mould is to make the plug as perfect as possible, so that means sanding and repainting then buffing to a polished finish

So now that we have a mint plug we can begin to mould it, note if you dont intend on changing any part of the fairing you can just start here!

-Firstly the plug must be throughly waxed and left to breath for 30mins between coats to allow the wax to hase off then all you do with a clean rag is wipe it off (wax on wax off styles) IMPORTANT you will need at least 8 coats of wax for a first time mould or you will have a stick up, and you probably wont get you plug out in one peice

-Once you have waxed it you apply tooling gelcoat or you can just use normal gelcoat, dont forget to catalise it (i find that it works fine)and apply it to the plug and allow it to cure (2-3hrs) next you do what is called a backup coat(apply a second gelcoat layer) this eliminates what is known in the trade as crocodiles caused through thin spot in the first layer of gelcoat

-Now we are ready to lay some glass on the plug, I would suggest that you make sure that the fairing is not twisted in anyway, if it is, i find that a few bits of timber glued on the inside of the fairing to hold it in winding will do the trick. So start off with P250 chopstrand as its easy to roll for you first layer and gets in any tricky bits, next layer go for a E450 chopstrand, then woven rovings say 800g will be good enough then another E450 over the top.

I say to use rovings as it stiffens up the entire mould however its tricky if you have never used it before.

Another trick to do to keep the mould from twitsing before you release it is the get the old cardboard reem rolls and cut them in half and glass them on to the mould this ensures that it will remail in the exact shape as the plug

So now you can release it hopefully you waxed it enough give the mould a few taps with a rubber mallet (not a hammer or you will crack the mould ) you can also ues a few wooded wedges as well to part the plug from the mould

and thats about it easy as

To successfully make a mould you will need

Chopstrand matt (emoulsion and powder)
Woven rovings What ever weight you want say around 850g
Polyester resin probably to be safe 1lter per lineal meter
Mekp (know as catalist/hardiner)
Gelcoat enough for the job
Mould release wax
A few paint brushes
A selection of rollers for rolling the fiber glass
Acetone (clean up and matain brushes and rollers)
Rags and heaps of them
Latex gloves
A resporator if you dont like the fumes
Foam(it you intend on modding the article)
Containers

Thats about all i can think of off the top of my head

If anyone needs advice give me a yell and ill point ya in the righ direction

**Mattzxr750** · 8th May 2006, 11:24

objective: is to make a better looking smaller and lighter rear for my zxr.

prep: need to strip off fairings and make a mold so that i have the basic shape

then slim it down and fill in the rear seat making it a solo bike.

build a fibregalss under body just for looks and some how mold in the indercators

i want to give it a more modern look