The use of wheat flour with epoxy makes me wonder why you are using epoxy. You might as well use wood dough. Wheat flour is basically starch with no fiber (lignin) and as such has no inherent strength. It functions more as a fairing agent in this application; which it will do nicely but gives up much of the strength of the epoxy. A better choice is to use the fairing agent that is used in most body putties and some epoxies- talc. It is cheap and you can get it at any dollar store for near the price of flour. It is likely the primary fairing agent in West System 405 filler-but that is a trade secret. Talc is ground stone and does not take up the epoxy and starve the joint by absorbing the epoxy as sawdust will do. There is some reduction in strength but it is minimal. It is easy to machine down and powdered pigment or stain can be added to the epoxy and talc mixture to get a color that you would want. Coloring does not work well with sawdust as the sawdust usually comes out too dark to start with once it is wetted with epoxy. I will be giving a presentation on adhesives in Seattle for more detailed information and how to make the best choices based on the science of adhesives. It will not be overly technical but very useful for daily choices of adhesives. Douglas Gregg Classic Piano Doc Southold, NY
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