Maintenance and Repair - West System Epoxy
Owning a boat requires maintenance and the occasional repair. This certainly holds true when it comes to your boat's hull. Knowing how to do your own epoxy repairs can save you money and give you the piece of mind and confidence that you are prepared when the unexpected happens. West System epoxy is a 2-part marine grade epoxy that bonds and coats fiberglass, wood, metal, fabrics and other composite materials to provide superior strength and moisture resistance.
Most of us are not chemists, however having a basic knowledge of how the process works will prove helpful when doing your own repairs. It all starts with the chemical reaction of mixing epoxy resin and a hardening agent. To keep it simple, once this reaction starts to occur your epoxy will pass from a liquid to a gel and ultimately to a solid state, which is referred to as the Cure Time. How long the mixture stays in each state is determined by a number of factors.
Open Time (Liquid) - This is the period of time you have to work with the product - apply it, spread it etc. Clamping and assembly should be done dureing the Open Time.
Initial Cure (Gel) - This is when the epoxy begins to "set-up". It is gererally tacky and not workable. A second application can be applied without special preperation at this time because a new epoxy will chemically bond to it.
Final Cure (Solid) - The epoxy is now in a solid sate and can be sanded and shaped to a more precise fit and finish. The epoxy is typically at about 90% of its final strength dureing this period.
What determines the Cure Time?
There are two main factors - Hardener Speed (Pot life) and Epoxy Temperature. The product guide will indicate the hardener speed and you should select this based on the amount of working time you require for the job. Basically the warmer the temerature of the epoxy the faster it will cure. Generally in warmer conditions you would want to use a slower hardener and perhaps mix smaller batches. The West System 205 is the Fast Hardener and the West System 206 is the Slow Hardener
West System has a complete set of free user guides that will provide you with helpful information every step of the way.