Sometimes the most difficult aspects of working on fiberglass projects at home is obtaining the proper supplies. Now that we have the internet, this is greatly simplified, and many online stores exist to sell many different types of resin and reinforcement; tools and supplies. One of the problems with this is the cost of shipping the resins as hazardous materials. And actually seeing and handling the reinforcement will help in determining if it is up for your application.
Sometimes it is advantageous to buy supplies
from a physical store. This saves time and money from shipping, and allows for better inspection of the purchased products. Local sources are not always easy to identify. Many times automotive bodyshop repair stores carry fiberglass resin. I have found that marine repair supply stores carry a more extensive repair supply, including epoxy, polyester, fiberglass sheeting, and even gelcoat and associated chemical additives.
When purchasing esins and gelcoats always keep in mind the shelflife. My experience has always been that polyester, vinylester, and gelcoat have about a six month shelflife from when it was manufactured. Be cautious at autobody supply houses that sell low volume amounts of resin and may have some old stock. Epoxy generally has a longer shelflife.
A good practice when obtaining new materials is to always do a test run in a small dixie cup, sometimes called a “Gel Test”. Mix the resin and hardener together and stir it up. Monitor the time it takes to start getting thick and lumpy. And time full hardness. As it gets towards full cure, there is potential to get hot enough to start a fire, so take proper precautions. This test will tell whether the resin and hardener are even compatible and what sort of working time to expect. This will make life much easier under actual fabrication conditions.