In its most simple form, the process of fiberglassing starts with very small strands of glass that are either woven together like a cloth, or chopped and then pressed together to form a mat. This material, which comes off of a roll, is then saturated with a two part epoxy or polyester resin that gets painted on in a thick viscus liquid. When the resin dries, the entire structure hardens and becomes rigid. Fiberglass can be used to make volumes and structures ranging from speakers to snowboards and is a valuable medium to work in when you want to create something that can't easily be cut out of wood or metal - curved 3D objects for example.
If the fiberglass is applied on a flat surface, it hardens into a flat sheet when dry and will act like any other rigid material.
However, if the fiberglass is applied over a form, say the ribs of a boat hull, then it can be used to create strong, lightweight volumes that can take on virtually any curve, contour or shape.
Because it can be used to create rigid curved surfaces, it's a process that is generally reserved for specialized building projects. See the following steps of some specific Instructables to see what I mean: step 11: Create subwoofer retrorockets and midrange 'eyes'
, step 16Fiberglassing your beaver
, Creating a fiberglass snowmobile trailer
amazing video/Instructable on making a fairing for a human powered vehicle
. When you need to make something that is rigid and curved, fiberglass is definitely the way to go.Terms:
Working with fiberglass comes with a whole new set of terms and lingo that it might be useful to know. I can't say that I will be using all of these words in my Instructable, but they are good to know anyway.Fiberglass
- very thin glass fibers that are treated like threads in a textileWoven vs. Chopped Mat
- woven mats contain fibers that are aligned and woven together like fabric, while chopped mats are made up of randomly aligned short fibers held together using a binder. Resin
- resin is the syrup like liquid that wets out the mat and then dries hard. It's activated by a hardener or second part.Polyester vs. Epoxy Resins
- polyester resins are cheaper, heavier and older then epoxy based resins. Polyester resins are activated by adding around 1.5% - 2% of total volume of resin that you are mixing of a hardener (MEKP). Epoxy resins come in a two parts that are mixed in more equal ratios )generally between 1:1 and 1:4). Epoxy based resins are stronger, have better adhesive properties then polyester resins and are more resistant to cracks and water. The major drawback is their price.MEKP
- Methyl Ethyl Keytone Peroxide - polyester resin catalyst (hardener)PVA
- Polyvinyl Alcohol (film mold release)Cabosil
- the white silica filler being mixed in (trade name - aka Aerosil or fairing filler)Tool
- negative mold used to make partsMicro Balloons
- air filler encapsulated in silica glass (creates a lattice matrix structure in resin)Gelcoat
- provides a high quality finish to composite tool surfaceComposite
- material made from two or more substances (in this case fiber glass and resin)Exotherm
- reference to the heat generated/required by the resin to curePot
- Catalyzed batch of resinPot Life
- Working/usable life of pot. After this time, the chemical reactions between catalyst and resin "take off"
**Much of this list is copied from Trebuchet03's fiberglassing glossary which originally appears here
Working with fiberglass is actually one of the more hazardous processes out there. The small fibers from the mat can cause skin irritations and tend to get all over the place. Fumes from the resin and cleaners that are used can cause long term damage and are full of all kinds of nasty VOC's (things that mess up the brain and the baby maker). And then there is the large amount of very fine dust that is created when sanding. It's not that working with this stuff is deadly, it's just that it must be dealt with in the proper way and using the proper precautions. When working with fiberglass you should be wearing:
- Painters suit (to keep the itchy dust off)
- Working in a well ventilated workspace (preferably outdoors)
Take everything that you were wearing and throw it away. You really don't want to wash clothing that has been exposed to fiberglass, or dust from sanding fiberglass with other clothes in the washing machine because you might just end up spreading the itchy strands all over your once safe clothing.Tools:
Aside from the resin and fiberglass itself, some other tools are required.
Useful places for more information and supplies:
- Power sanders
- Sanding pads and sandpaper
- Mixing bowl (a disposable plastic container is fine)
- Mixing stick (piece of scrap wood)
- Measuring tools - pumps that dispense the resin and the hardener in the correct ratio or a measuring cup
- Disposable paint brush
- Solvents for cleaning
There are tons of good tips already published right here on Instructables. Here are just a few.Mixing Polyester Resin
by Trebuchet03Handy Tricks
(for removing fiberglass from skin) by TimAndersonEpoxy Laminating Systems
by freemanmfgFiberglass Tools and Tricks
by unclesamUsing Paper, Resin and Fiberglass to be the Master Chief!
Here are some companies that sell fiberglassing supplies.US Composites
has a wide range of resins.West System
is a good source for marine resins and fillers.System Three
has tons of marine application resin
has many locations in the bay area and stocks a wide range of resin's fiberglass mat, and the tools needed to work with it all. They also have some informative .pdf's located in their FAQ section
Check out your local store to get an idea of what you'll need and then see what's online. If you don't happen to be next to a major retailer of fiberglass supplies, it could be a good idea to order online since the price of resin varies wildly depending on where you get it.