Notes on Using Epoxy Resins for High Power Rocketry
Epoxy is an amazing product that can allow regular people to become Aerospace Engineers, building advanced composite airframes out of exotic materials, from fiberglass to aramid. Its use covers many industries and permeates almost all of production in some way. Once dried, epoxy becomes fairly inert and reasonably chemically resistant. When liquid, it can fill many unexpected places, especially with a vacuum-assist. It is self-leveling until it sets, allowing beautiful fillets on your rocket’s fins. Epoxy gives strength to the weary, and as such, it is biblical in its proportions.
Epoxy is required for High Power Rocketry. It always comes in two-part form; containing a resin and a hardener mixed, usually, in equal parts by volume. There is no true epoxy that can be made without two separate parts.
Health Concerns
Epoxy solvent and resin fumes are extremely unhealthy!
Please first read, and believe, everything the package says regarding toxicity and health impact of the epoxy you are using. While epoxy may be reasonably safe once fully cured, we assure you those solvents are very unsafe for lungs and skin while “raw”. Do not breath the fumes from the epoxy solvents before it has cured fully. Please wear respirators with filter elements made for organic vapors. Such as the 3M™ Solvent and Chemical Respirator. Please do not wear dust masks, they do not filter out organic solvents. Please wear chemically-resistant gloves, as the solvents in epoxy can melt your skin. We use disposable mechanics gloves when using epoxy, and we keep the gloves as clean as possible during the process, even wiping them with a paper towel to keep epoxy contamination under control.
As an official safety reference, following is the MSDS for West Systems epoxy, which is a great overall epoxy product for making anything from rockets to sailboats:
West System Epoxy Material Safety Data Sheet
If you have access to a garage, or outdoor work shop, ventilation may not be a major concern, but even fresh air won’t prevent the solvents from entering your lungs while breathing directly above the mixture.
If you do all your epoxy jobs indoors, please be aware of the impact of the fumes on your indoor space. Can you get fresh air indoors? Will the heavier-than-air fumes drop to the floor and affect pets, or reach an open flame? Will the fumes be trapped indoors, and recycled into the air for repeat breathing? Anything more than a tablespoon worth of epoxy will probably add a smell to the air that certainly indicates toxicity.
