Yes, additional layers of epoxy resin may be applied one on top of another; but the method of application will vary depending upon whether the additional coats of resin are applied when the prior coat is fully cured or not. If the epoxy is completely cured, you’ll need to lightly sand the surface to ‘rough it up’ and give the new layer of epoxy resin something to cling to. After sanding, wipe or rinse off the dust (drying thoroughly if rinsed). Then another layer of epoxy resin may be applied. Alternatively, if the surface hasn’t cured fully and is still tacky to the touch—but no resin sticks to your finger—you’re at the right stage to apply another coat of epoxy resin.