Topic: fiberglassing: anyone ever done it?

[paulages]

this article in the technical library makes me want to build the dunstall-replica i couldn't afford on ebay or from airtech:

http://sohc4.us/?q=node/53

it's pretty informative, but i've never laid glass, and am looking for more discussion about how it's laid, how many layers to use for a fuel tank, etc.

[eldar]

Gee  idont know how well fiberglass would dork with fuel. I think you would have to line the tank with a sealant.
Otherwise you could build a slightly small mold out of some material then lay the fiber ove rit and layer it.
I have never done glasswork but I would think that you need something to lay the glass on for proper curves.

[eldar]

Generally 71-76 had the same style carb kits. You still want to find out the year for sure though as there could be jet changes or the seller could have slipped you a set of 77-78 carbs.

[dusterdude]

i agree with eldar on the tank,i would definetly line the glass with something that will hold gas.if you decide to make a mold and form the glass to it,use something like pam cooking spray as a release agent.spray it on the mold then lay the glass onto the mold.ummm eldar,did i miss the carb question here?

[eldar]

Not sure what the deal is with that. That should have gone to a different topic??
Very strange as I was in the correct topic when I posted it.

[dusterdude]

yea sure.we believe ya

[Sam Green Racing]

I have built quite a few tanks over the years and have never had a problem with not sealing/ coating the inside.

You would only have to do it if you use methanol as your fuel.

Sam.

[Geeto67]

I tired to build my own tank years ago. I never had a problem with fuel eroding the tank, but I just couldn't get it to seal right through my methods. I made a buck out of styrafoam, then I coated it with glass, then I used lacquer thinner to dissolve the foam. In the end I went down to the radiator shop I worked at and had them put a redliner in it (thick plastic coating) and that worked to seal it up. I ended up cracking the tank weeks later in a laydown (the redliner still  held the fuel without leaks but I didn't like the look and scrapped it).

[Sam Green Racing]

It's a load of hard work but it can be worth it, when someone asks you where you got it.

[paulages]

the method layed out in that article seems pretty straight forward: carve a mold out of styrofoam, paint it with oil based paint to protect the foam from the resin; glass under, then bondo on your petcock, mounts, and fuel filler cap; glass the whole thing; dissolve the foam; line the tank; and finish/paint.

i've just never glassed before, and i'm looking for specific advice about what type of glass to lay up, how many layers, etc. i'm sure i can get some good tips from whoever sells the supplies...

[Sam Green Racing]

Whats your location ?

[LeoLegendATL]

how would you go about doing the threads for the petcock and such, im a little lost on those parts

[stivh]

Make sure that you work in even layers and cross matt in thin strips about 5cm by 20 cm adding etc on the edges and load bearing points use a fine grade of glass and ensure that you get all the air bubbles out when layering if you can use a small roller even better, obviously ensure that you use the correct ratios when mixing the resin and don't forget to add your pigment colour to the mix as this will help in final painting if not using a tinted etch primer..

oh ...........and don't forget the rubber gloves!

[TwoTired]

the method layed out in that article seems pretty straight forward: carve a mold out of styrofoam, paint it with oil based paint to protect the foam from the resin...

You only need to prepaint the foam if you use a polyester resin.  Or, if you reduce an epoxy resin to make it thinner.  Epoxy resins won't attack foam, but it costs more than the polyester type.

The glass itself is sold in many forms.  Matt, cloth, and woven are most common.  Matt conforms to compound curves easier.  But will sometimes require more resin to fill and saturate.  The glass is sold by weight per area.  And, that relates to it's individual thickness; 3/4 oz, 1 oz, 2 oz etc.
Structurally is is quite strong and needs only double or triple the thickness of steel to acheive the same strength.
Some people are alergic to the resins used.  You might want to practice making a small sample to find out.

http://www.tapplastics.com

These people have everything you need for your project.  They can ship if you can't find a store or an equivalent supplier close by.
Cheers,

[paulages]

how would you go about doing the threads for the petcock and such, im a little lost on those parts

i believe the idea is to glass a layer or two in the required area, then bondo on the neccesary parts cut off of a donor tank, then glass over the "flange" metal you left around the filler neck, petcock nipple, whatever. then afterwards, the hole inside the nipple or fuel filler is cut out of the glass beneath it.

thanks for all the advice, guys. i'll let you know how it turns out, if i ever find the time to try it.

[Bodi]

Fiberglass resin sold for car body repairs has been fuel-proof in my experience. Maybe boat stuff isn't, I dunno.
Fiberglass is hellish nasty to work with. Once the hardener is mixed in the resin starts to gel pretty quickly; you have about 30 minutes maximum per batch before it's too thick to work with. Possibly there are tricks to slow this down? Plus it stinks really bad.
The woven matt makes the best final product but turns into an unruly slime sheet when the resin is applied. The edge fibers come loose and form unpleasant globs that are next to impossible to get off the work or your gloves (or hands if you have rhino skin that doesn't go nasty in the chemicals).
The non-woven matt is thicker but for a given thickness, multiple layers of woven matt will be stronger than the random matt.
Whatever tray you mix the resin for dipping the matt pieces in will be garbage after one mix; if you need 10 batches you'll need 10 trays. Cutting the sheet makes masses of fiber dust that will make you ITCH like mad and they are tough to wash out of clothes; don't wash the 'glassing clothes with anything else or your whole wardrobe will be unwearable. The final finish is pretty rough and will need to be bondo'd and sanded before you get a decent finish. All boat and car body fiberglass parts are made "inside out": on a mold of the outside of the finished part they spray a coloured epoxy "gel coat" which is the surface you see, then the real fiberglass is applied on top (underneath the finish surface) either with matts or a "chopper gun" that chops glass cord into short pieces then sprays them out mixed with resin.
I have no idea how one would make the nice looking "carbon fibre" type finish where a nice even woven matt is smoothly coated with clear blemish-free epoxy. You can put down dry matt and spread resin over it but the edges always unravel and make a mess when I try that, you need to do a lot of squeegying or rolling to saturate the matt and get the bubbles out... and the matt has turned to that loose sheet of slime that does not want to stay pretty.

[paulages]

well that's a pretty realistic and encouraging/discouraging description. i imagine my first attempt will look like a preschool papermache project, but i usually pick things up pretty quickly, and i'm a bit TOO anal about detail, so maybe that's a good thing.

by the way, someone asked, and i'm in portland, oregon.

i believe i read somewhere, where a similar type coating to a base gelcoat is applied last, which leaves work/sandability.

[alfabeast]

You can always use carbon fiber for that racing look, just make the first two layers from carbon fiber and the rest with glass to save money, you could use all carbon but unless it's vacuum formed/autoclaved it wont be any stronger than f/glass.

I made a rear fender by making a fiberglass mold of my tyre and then laid carbon fiber in the mold.

A seat I made by using a bent piece of thin steel as a mold.

Here's a street tracker body kit I made using clay and plywood as a mold:
http://home.earthlink.net/~alfabike/id1.html

You can use all kinds of things for molds, I've made covers useing plates and handlebar switch cases using little tupperware pots.