Using Fibreglass and Epoxi - what could you build?

[MaaTini]

I try to get familiar with the Idea, to use Epoxy and Fibreglass to build me a small Watervehicel

basicly, it should become a Catermaran - using 2 Kayaks as my Base and completing the "Deck" with Epoxi and Fibreglass

a small Engine would complete me Task - and a "Ruder" of course ...

I must admit, I rarely have used these Materials - beside Fixing rusty Holes on my old Cars Long time ago - and it ended up messy...

But basicly - it should be not too difficult to use these Materials to build nearly everything

Whatever you have built with Epoxy or similar Materials - post it here and give me and others an Idea or Advice, for what it could be used

Even if you just have thought about to do somoething similar - lets share the Idea

Cheers

[MegaRanter]

Sex toys comes to mind.

[RandomSand]

You'd need a stainless steel metal frame to mount your outboard's mounting bracket onto, wouldn't you ?

I guess it will end up costing more than off-the-shelf.

Wikipedia has some information : http://en.wikipedia.org/wiki/Hull_(watercraft)

[David48]

If you are building in Thailand ... have a read of this. need-plans-for-a-long-tailed-boat

Might give some clues to help with some parts of the boat build.

[impulse]

Buy 2 kayaks and go down to BKK Chinatown metals market and buy aluminum extrusions (or stainless "angle iron") and stainless nuts and bolts to make them into a catamaran. If you're handy with wood, that's probably even easier than metals. With the great woods available in Thailand, wood may be a better choice, especially for a one-off.

A little bit of wood for your motor mount and you're good to go. You can be as creative as you like with masts, rudders, daggerboards, etc.

If you want a sea worthy craft, use stainless "angle iron" instead of aluminum extrusions. Aluminum corrodes very quickly in seawater unless i's anodized. Great for lakes, poor for seawater. And you'll get dis-similar metal corrosion wherever you have a stainless fastener in contact with aluminum.

Besides, you can weld on stainless with a cheap household welder. Welding aluminum requires industrial grade equipment with an industrial price.

Working with fiberglass and epoxy isn't for the feint of heart. And most people mistakenly identify polyester resin as "epoxy". If you can smell it from 5 meters away, it's polyester, not epoxy. And it's a nightmare to work with on a large scale.

By the time you make (or buy $$$$$) a fiberglass mold and locate the resins and glass cloth, you'll find that you wish you had just gone with indigenous processes like plywood, strip construction, or just farming it out.

Edited January 20, 2014 by impulse

[weegee]

Fiberglass is great...but...if you don't use it properly, and protect yourself. you can end up with skin disease from it...especially epoxy resin.

Don't do it until you have checked as much as possible on the subject.....

Cheapest way is Plwood and cover it with fibreglass and woven matting....But the plywood must be made with waterproof glues, or it will delaminate.

[tonytigerbkk]

If you want a (decent smooth) surface on the fibreglass you will need to make a negative mould (the negative mould is the actual production mould).

There are many ways and materials that can be used to make the mould but the easiest way to do this (on a non commercial scale) are as such:

1. First you will need to make a positive mould (AKA plug or master mould).
2. To make the plug make a rough mock up of the object the same shape as the finished product that you are making.

The best way to do this is to make a wooden frame work, build the area up with plywood and then built it up with plaster.

1. Smooth the plaster down to the exact shape as the object that you are making, the smoother the surface the better the finish will be.
2. Apply a layer of gel coat, this is done so that the negative mould can be released from the plug.
3. When the gel coat is lay the fibreglass onto the plug.

You should use at least 3 layers of 450 woven mat and a low shrink epoxy resin.

1. Leave the fibreglass to dry and cure (around 24 hours) and then release the production mould from the plug.
2. Apply a layer of gel coat to the production mould than hand lay the fibreglass and epoxy using the same materials as in step 5.

If you are making a canoe then you would need 2 moulds, a top mould and a bottom mould.

For this it would be better to build flanges on the production moulds, so the 2 moulds can be bolted together to join the 2 parts.

To join 2 fibreglass parts use epoxy resin which will infuse the parts and give a waterproof seal.

The 2 part mould method is long and fairly difficult but if you do this correctly then the finish is great and the moulds can be used over and over again.

Sorry if my instructions are a but hard to follow but I’m not really a wordsmith, so I just write these down in a way that I think can be understood.

[dave2]

re

a small Engine would complete me Task

you dont wanna do that

dave2

[mikecwm]

I've built or rebuilt 4 sail boats using ply, fibre glass and epoxy resin. Epoxy is 4 times the price of polyester resin, but lasts forever. It is also the only resin you can use over the top of polyester (if you were patching an older boat - never use polyester over the top of epoxy - it won't stick).

Always wear gloves when you're mixing or applying epoxy - you very quickly become allergic to it otherwise - then just getting a small amount on the fingers will bring out a rash around the crotch (my experience anyway).

Aluminum for brackets is fine as long as you hose them off with fresh water when you take it out of salt water. Cheap to buy, easy to cut and drill to bolt pieces together. You can drill with just a battery drill.

Stainless does require a good workshop in order to drill - and a really good set of drill bits - which will need constant cooling oil if you don't want them glowing red and going dull before you've even drilled through one hole.

I also built a box car for my son - unfortunately he grew faster than I could complete it and by the time I finished he could barely squeeze in. Had to sell it after just a trial run.

Here's a link to a great site for all sorts of advice - http://www.gougeon.com/

Can't see a way to load images of the boats I've built, but that would be bragging anyway. All multihull - tri and cat. Multihulls for sailors is a kind of expensive disease.

Wait - found the link to add photos. Here goes with the bragging!

Edited January 26, 2014 by mikecwm