Epoxy is different from most glues in that it is a mechanical bond. It will bond to most rough surfaces. To glue metal first sand with 80 grit then wash with acetone.
Epoxy is a two part glue. There is a resin and a hardener. It is very important to have an even mixing between the two parts. For very small amounts mixing with a plastic stick on a piece of wax paper or plexiglass works well. Avoid using wood as it can absorb the chemicals differentially. Scrape the entire amount of glue off the mixing pallet often and mix to insure the epoxy nearest the pallet gets mixed in.
For slightly larger amounts a paper Dixie cup works well. Make sure to scrape the sides and the bottom while mixing. 45 seconds of stirring and 15 seconds of scraping is a good rule of thumb.
For very large amounts there are drill attachments and instructions are included with their purchase.
For large amounts it is good to use a respirator.
Calculating Epoxy Needed for a Fabric Layup
-from West Systems
This formula will help you estimate the amount of mixed epoxy needed to wet out fiberglass cloth (assuming a resin-to-fiber ratio of 50:50) and apply three rolled epoxy coats to fill the weave of the cloth, i.e. "fill coats."
The formula includes a waste factor of approximately 15%; however, more (or less) may be needed depending on the job and personal application technique. The epoxy is applied at standard room temperature, approximately 72° F.
Gallons of mixed epoxy=A×[(Wf×0.00085)+0.0075]
Where: A=Total area covered by fiberglass. Units are in square feet (ft^2) Wf =Total weight (W) per square yard of fiberglass (f) cloth used in laminate. Units are in ounces per square yard (oz/yd^2), i.e. 6 oz fiberglass cloth weighs 6 oz/yd^2.