Mixing epoxy

To get good results, you should measure the epoxy carefully and mix thoroughly.

You can mix small amounts with little measuring cups - disposable ones can be purchased from most epoxy suppliers like marine shops. The major manufacturers also sell pumps for their epoxies. These pumps dispense a fairly exact amount with each stroke of the pump. If you do a lot of epoxy work, the pumps are probably a good idea. For critical applications, measuring by weight is the answer. Be aware that a 2:1 ratio by volume does not equal a 2:1 ratio by weight. Small electronic scales work well and most manufacturers will provide a data sheet that lists the specific gravity of both hardener and resin so you can compute proper ratios.

When mixing epoxy, use a clean container. Reusing a container with partially cured epoxy can set off the new batch, especially if you are using a fast-curing epoxy. Many containers are suitable - old yogurt or margarine tubs are good as are clean food tins. Use the widest mouth you can for the amount, since a wide shallow pot will not overheat as much as a deep, narrow pot.

Wooden stir sticks or tongue depressors (buy these at a craft store for 1/10 the cost of those in the epoxy display) are good for mixing. You can also use plastic spoons or knives. Make sure you mix the epoxy thoroughly. Scrape the sides of the container and make sure you get the material down in the bottom corners. An uneven mix will not cure properly and you will waste a lot of time and effort.