i need to make a curved fibreglass tube, and i was wondering how i could do this. i've used fibreglass before but i am trying to figure out how i can make a mould to lay the glass over, that can be removed after. anyone?
i have thought about using a clown type balloon, but i need something that is gonna stay curved until the resin dries.
how do they make cold air intakes?

 

What kind of curve are you looking for?

I know i used to use fabric over my speaker boxes, then fiberglass over the fabric to get those nices curves... Works well.

 

The way pros do it is with custom made inflatable bladders. A cheap way to do it is to make your plug out of styrofoam, layup your glass with epoxy, then melt the foam away with styrene. You must use epoxy though because polyester resin will melt the foam.

 

a two-part mould will work if the bend isnt in too many inaccessible planes also

 

I would go to home depot's plumbing section. they have all manner of rubber and plastic hose (think garden hose consistency or various diameters and flexibility).

i would then plug one of the ends and fill the onther end with expanding foam. before the foam dries bend it in the shape you want. maybe making a jig of some sort would help.

once it hardens you now have a pretty good buck to make your mouldings from.

good luck.

 

thanks for the advice, i will try out some of your ideas

 

use any tupe of tubing wrapped in foil or baking sheet with a light coat of vaseline remove fiberglass before resin is 100 percent hardened

 

We did some prototype carbon fiber elbows a year back. We took an existing steel elbow that was fabricated to the dimensions we needed. Then we built a two piece mold with a dividing line down the center axis of the piece. We bought some special plastic stuff that expanded inside the mold and held shape. Then we wrapped the the carbon (1" strips) around this cast plastic piece with a low level of epoxy impregnation. When it hardened they melted the cast interior piece out and we had our elbow.